Search Results

Search found 25300 results on 1012 pages for 'internet speed'.

Page 749/1012 | < Previous Page | 745 746 747 748 749 750 751 752 753 754 755 756  | Next Page >

• Serving images from another hostname vs Apache overload for the rewrites

  - by luison

  We are trying to improve further the speed of some sites with older HTML in order as well to obtain better SEO results. We have now applied some minify measures, combined html, css etc. We use a small virtualized infrastructure and we've always wanted to use a light + standar http server configuration so the first one can serve images and static contents vs the other one php, rewrites, etc. We can easily do that now with a VM using the same files and conf of vhosts (bind mounts) on apache but with hardly any modules loaded. This means the light httpd will have smaller fingerprint that would allow us to serve more and quicker, have more minSpareServer running, etc. So, as browsers benefit from loading static content from different hostnames as well, we've thought about building a rewrite rule on our main server (main.com) to "redirect" all images and css *.jpg, *.gif, *.css etc to the same at say cdn.main.com thus the browser being able to have more connections. The question is, assuming we have a very complex rewrite ruleset already (we manually manipulate many old URLs for SEO) will it be worth? I mean will the additional load of main's apache to have to redirect main.com/image.jpg (I understand we'll have to do a 301) to cdn.main.com/image.jpg + then cdn.main.com having to serve it, be larger than the gain we would be archiving on the browser? Could the excess of 301s of all images on a page be penalized by google? How do large companies work this out, does the original code already include images linked from the cdn with absolute paths?

  Read the article

• Recover badly recorded DVDs

  - by CesarGon

  A few years ago (2003-2005) I bought a Sony USB external DVD recorder for my Dell laptop and I used it to burn a lot of discs. Much later, when I tried to use one of these discs, I realised that I could not read it. The disc behaved as if it was scratched or dirty. I tried on a couple of different DVD drives but got the same effect. Sadly, all the discs that I burnt with that recorder suffer from the same problem. Edit. When I read one of these discs with ImgBurn, I get lots of unrecovered read errors in multiple sectors, even at 1x speed. The sectors that cause read errors seem to be quite random; it's not always the same one. I have no idea what could be wrong with the discs. I doubt that they are scratched or dirty; it would be too much of a coincidence that all the discs that I burnt with that recorder got damaged at the same time. Also, they don't show any physical defects. Is there any way to diagnose what the problem is and, hopefully, recover the contents of the discs? Many thanks.

  Read the article

• Remote Desktop Services Licensing - Does server have to have a RDS role?

  - by transistor1

  I recently set up a "micro" size Windows 2008 Datacenter server on Amazon AWS. My small group needs several concurrent RDS users to be able to access the machine. Without installing the "Remote Desktop Server" role, it allows 2 concurrent connections. I read on MS' website that in order to set up multiple users, we needed to install the RDS role. I did so, but now the application we are trying to share is running much slower than it was before. Prior to the role installation, it was taking about 5 seconds to open; now it is taking a few minutes to open -- without any other users logged on except me. My assumption is that the RDS role may be too much for this micro instance to handle, and currently, changing to another size instance is not an option (it may be possible later if we were to receive enough funding). This leads me to the following questions: 1) Is it a sensible assessment to assume that it is the RDS role is slowing things down, or are there other things that I could look at to speed it up? We are talking about a machine with ~600MB of memory. 2) If I revert back to the pre-RDS role, is there any legitimate way (in terms of purchasing RDS licenses) to get more than 2 concurrent desktops? I did read this, and am not questioning that the answerer is knowlegeable; but someone else may have some other experience. I am also making it clear that we want to do this in a legitimate way. Thanks in advance for any assistance that can be provided! EDIT: if it is helpful in answering the question, the application in question is a Lotus Approach database. Also, I am asking this from a technical perspective: not a legal one. I want to know if it is possible to install valid licenses without the RDS role.

  Read the article

• Matched or unmatched drives for RAID arrays?

  - by Will

  Looking around there is conflciting information on this, with some strongly suggesting one or the other. From my understanding the issue with matched drives is that the wear on both drives is more or less the same, so the potential for the second drive failing with or very soon after the first is pretty high. People also claim matched drives give substianatally higher performance however assuming the unmatched drives are more or less the same (eg 2, 1 TB STATA II 7200rpm drives with 32MB cache), would the minor differences between say a Seagate and a Western Digital one (say one has a 128MB/s read rate, and the other a 150MB/s read rate, as well as I guess various other minor differences) actually cause any notable performance loss, ie potentialy worse than two matched 128MB/s drives, or does RAID not really care and give you essentially an optimal solution (eg upto 278MB/s total read speed for RAID 0 and 1) and similar for other RAID with more "unmatched" drives (5 and 1+0 come to mind as possibilities)? Also I couldnt find much info on how this is different on different RAID setups, eg RAID 0 or RAID 1, software or hardware RAID, etc. I'm assuming such things have an effect, and thats it's not all the same for RAID in general?

  Read the article

• Backtrack, Wi-Fi not working

  - by hradecek

  I've installed Backtrack 5R3 KDE, and I realized that my wireless is not working, but wired is working fine. Here's the lshw output: *-network description: Ethernet interface product: RTL8101E/RTL8102E PCI Express Fast Ethernet controller vendor: Realtek Semiconductor Co., Ltd. physical id: 0 bus info: pci@0000:02:00.0 logical name: eth0 version: 05 serial: 04:7d:7b:b7:46:f8 size: 100MB/s capacity: 100MB/s width: 64 bits clock: 33MHz capabilities: pm msi pciexpress msix vpd bus_master cap_list ethernet physical tp mii 10bt 10bt-fd 100bt 100bt-fd autonegotiation configuration: autonegotiation=on broadcast=yes driver=r8169 driverversion=2.3LK-NAPI duplex=full firmware=rtl_nic/rtl8105e-1.fw ip=192.168.2.2 latency=0 link=yes multicast=yes port=MII speed=100MB/s resources: irq:42 ioport:2000(size=256) memory:f0404000-f0404fff memory:f0400000-f0403fff lspci output: 00:00.0 Host bridge: Intel Corporation 2nd Generation Core Processor Family DRAM Controller (rev 09) 00:02.0 VGA compatible controller: Intel Corporation 2nd Generation Core Processor Family Integrated Graphics Controller (rev 09) 00:14.0 USB Controller: Intel Corporation Panther Point USB xHCI Host Controller (rev 04) 00:16.0 Communication controller: Intel Corporation Panther Point MEI Controller #1 (rev 04) 00:1a.0 USB Controller: Intel Corporation Panther Point USB Enhanced Host Controller #2 (rev 04) 00:1b.0 Audio device: Intel Corporation Panther Point High Definition Audio Controller (rev 04) 00:1c.0 PCI bridge: Intel Corporation Panther Point PCI Express Root Port 1 (rev c4) 00:1c.1 PCI bridge: Intel Corporation Panther Point PCI Express Root Port 2 (rev c4) 00:1d.0 USB Controller: Intel Corporation Panther Point USB Enhanced Host Controller #1 (rev 04) 00:1f.0 ISA bridge: Intel Corporation Panther Point LPC Controller (rev 04) 00:1f.2 SATA controller: Intel Corporation Panther Point 6 port SATA AHCI Controller (rev 04) 00:1f.3 SMBus: Intel Corporation Panther Point SMBus Controller (rev 04) 02:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8101E/RTL8102E PCI Express Fast Ethernet controller (rev 05)

  Read the article

• VPS goes slow at more than 20 users online at the same time

  - by hachiari

  I have 512 MB VPS (brustable to 1GB) Somehow, the site goes slow when there are about 10 users, and becomes impossible to load at 20 users online at the same time. I wonder what could be the problem for this. The bandwidth connection of the VPS is 1Gbps. Here is some settings in my VPS: KeepAlive Off <IfModule prefork.c> StartServers 7 MinSpareServers 7 MaxSpareServers 10 ServerLimit 64 MaxClients 64 MaxRequestsPerChild 0 </IfModule> my.cnf settings - calculated Max Memory 300MB Output from UNIXBENCH INDEX VALUES TEST BASELINE RESULT INDEX Dhrystone 2 using register variables 376783.7 13429727.4 356.4 Double-Precision Whetstone 83.1 1137.5 136.9 Execl Throughput 188.3 1637.4 87.0 File Copy 1024 bufsize 2000 maxblocks 2672.0 148868.0 557.1 File Copy 256 bufsize 500 maxblocks 1077.0 79430.0 737.5 File Read 4096 bufsize 8000 maxblocks 15382.0 1410009.0 916.7 Pipe Throughput 111814.6 4419722.0 395.3 Pipe-based Context Switching 15448.6 561505.1 363.5 Process Creation 569.3 10272.7 180.4 Shell Scripts (8 concurrent) 44.8 514.3 114.8 System Call Overhead 114433.5 3537373.8 309.1 ========= FINAL SCORE 295.0 I am afraid that the VPS company limit the number of connection to the VPS... is it possible? The server is in Japan, but the site has global traffic (some of the traffic are from countries with low speed connection). Could this be the problem? This is a serious problem :( my site just cant grow if this keeps on happening... please tell me if you have any idea. Thank You, Bryant

  Read the article

• How large is the performance loss for a 64-bit VirtualBox guest running on a 32-bit host?

  - by IllvilJa

  I have a 64-bit Virtualbox guest running Gentoo Linux (amd64) and it is currently hosted on a 32-bit Gentoo laptop. I've noticed that the performance of the VM is very slow compared to the performance of the 32-bit host itself. Also when I compare with another 32-bit Linux VM running on the same host, performance is significantly less on the 64-bit VM. I know that running a 64-bit VM on a 32-bit host does incur some performance penalties for the VM, but does anyone have any deeper knowledge of how large a penalty one might expect in this scenario, roughly speaking? Is a 10% slowdown something to expect, or should it be a slowdown in the 90% range (running at 1/10 the normal speed)? Or to phrase it in another way: would it be reasonable to expect that the performance improvement for the 64-bit VM increases so much that it is worth reinstalling the host machine to run 64-bit Gentoo instead? I'm currently seriously considering that upgrade, but am curious about other peoples experience of the current scenario. I am aware that the host OS will require more RAM when running in 64-bit, but that's OK for me. Also, I do know that one usually don't run a 64-bit VM on a 32-bit server (I'm surprised I even got the VM started in the first place) but things turned out that way when I tried to future proof the VM I was setting up and decided to make it 64-bit anyway.

  Read the article

• Can't configure frame relay T1 on Cisco 1760

  - by sonar

  For the past few days I've been trying to configure a data T1 via a Frame Relay. Now I've been pretty unsuccessful at it, and it's been a while, since I've done this so please bare with me. The ISP provided me the following information: 1. IP address 2. Gateway address 3. Encapsulation Frame Relay 4. DLCI 100 5. BZ8 ESF (I think the bz8 was supposed to be b8zs) 6. Time Slot (1 al 24). And what I have configured up until now is the following: interface Serial0/0 ip address <ip address> 255.255.255.252 encapsulation frame-relay service-module t1 timeslots 1-24 frame-relay interface-dlci 100 sh service-module s0/0 (outputs): Module type is T1/fractional Hardware revision is 0.128, Software revision is 0.2, Image checksum is 0x73D70058, Protocol revision is 0.1 Receiver has no alarms. Framing is **ESF**, Line Code is **B8ZS**, Current clock source is line, Fraction has **24 timeslots** (64 Kbits/sec each), Net bandwidth is 1536 Kbits/sec. Last module self-test (done at startup): Passed Last clearing of alarm counters 00:17:17 loss of signal : 0, loss of frame : 0, AIS alarm : 0, Remote alarm : 2, last occurred 00:10:10 Module access errors : 0, Total Data (last 1 15 minute intervals): 0 Line Code Violations, 0 Path Code Violations 0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins 0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs Data in current interval (138 seconds elapsed): 0 Line Code Violations, 0 Path Code Violations 0 Slip Secs, 0 Fr Loss Secs, 0 Line Err Secs, 0 Degraded Mins 0 Errored Secs, 0 Bursty Err Secs, 0 Severely Err Secs, 0 Unavail Secs sh int: FastEthernet0/0 is up, line protocol is up Hardware is PQUICC_FEC, address is 000d.6516.e5aa (bia 000d.6516.e5aa) Internet address is 10.0.0.1/24 MTU 1500 bytes, BW 100000 Kbit, DLY 100 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation ARPA, loopback not set Keepalive set (10 sec) Full-duplex, 100Mb/s, 100BaseTX/FX ARP type: ARPA, ARP Timeout 04:00:00 Last input 00:20:00, output 00:00:00, output hang never Last clearing of "show interface" counters never Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0 Queueing strategy: fifo Output queue: 0/40 (size/max) 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 0 packets input, 0 bytes Received 0 broadcasts, 0 runts, 0 giants, 0 throttles 0 input errors, 0 CRC, 0 frame, 0 overrun, 0 ignored 0 watchdog 0 input packets with dribble condition detected 191 packets output, 20676 bytes, 0 underruns 0 output errors, 0 collisions, 1 interface resets 0 babbles, 0 late collision, 0 deferred 0 lost carrier, 0 no carrier 0 output buffer failures, 0 output buffers swapped out Serial0/0 is up, line protocol is down Hardware is PQUICC with Fractional T1 CSU/DSU MTU 1500 bytes, BW 1536 Kbit, DLY 20000 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation FRAME-RELAY, loopback not set Keepalive set (10 sec) LMI enq sent 157, LMI stat recvd 0, LMI upd recvd 0, DTE LMI down LMI enq recvd 23, LMI stat sent 0, LMI upd sent 0 LMI DLCI 1023 LMI type is CISCO frame relay DTE FR SVC disabled, LAPF state down Broadcast queue 0/64, broadcasts sent/dropped 2/0, interface broadcasts 0 Last input 00:24:51, output 00:00:05, output hang never Last clearing of "show interface" counters 00:27:20 Input queue: 0/75/0/0 (size/max/drops/flushes); Total output drops: 0 Queueing strategy: weighted fair Output queue: 0/1000/64/0 (size/max total/threshold/drops) Conversations 0/1/256 (active/max active/max total) Reserved Conversations 0/0 (allocated/max allocated) Available Bandwidth 1152 kilobits/sec 5 minute input rate 0 bits/sec, 0 packets/sec 5 minute output rate 0 bits/sec, 0 packets/sec 23 packets input, 302 bytes, 0 no buffer Received 0 broadcasts, 0 runts, 0 giants, 0 throttles 1725 input errors, 595 CRC, 1099 frame, 0 overrun, 0 ignored, 30 abort 246 packets output, 3974 bytes, 0 underruns 0 output errors, 0 collisions, 48 interface resets 0 output buffer failures, 0 output buffers swapped out 4 carrier transitions DCD=up DSR=up DTR=up RTS=up CTS=up Serial0/0.1 is down, line protocol is down Hardware is PQUICC with Fractional T1 CSU/DSU MTU 1500 bytes, BW 1536 Kbit, DLY 20000 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation FRAME-RELAY Last clearing of "show interface" counters never Serial0/0.100 is down, line protocol is down Hardware is PQUICC with Fractional T1 CSU/DSU Internet address is <ip address>/30 MTU 1500 bytes, BW 1536 Kbit, DLY 20000 usec, reliability 255/255, txload 1/255, rxload 1/255 Encapsulation FRAME-RELAY Last clearing of "show interface" counters never And everything seems to be accounted for to me, but apparently I'm missing something. My issue is that I'm stuck on interface up, line protocol down, so the T1 doesn't go up. Any ideas? Thank you,

  Read the article

• Ram configuration 4x4 or 2x8?

  - by Carl B

  I am looking to upgrade my Ram to 16gigs and I am wondering if there is any distinct advantage of the way I do it. That being a 4x4 or 2x8 set up. In all my searching there have been a number of pros for each profile. I can find no benchmarck results for either setup as a compaison. So, if there are 2 profiles of the same speed, same voltage, same timing and same cas what would perform better or have a better over all benafit? A few examples from my search - a 4x4 set would lend a benafit in that if one stick failed, you only lose 25% of your Ram vs 50% in a 2x8 set up. a 2x8 set up would have less strain on the memory controler and motherboard. a 2x8 would generate less heat. a 2x8 set up is easier to over clock (not part of my need, but alot of the comparisons circled around the overclocability ease of the 2 stick set up). There is one outstanding benafit that I have found in at least the target company I have looked at and that is price. The 2x8 is nearly half the cost. My motherboard supports a max of 16 gigs and I have a 64 bit OS. Has anyone seen any performance comparisons or is 16 gb just 16 gb no matter how you slice it? And is there any merit to the above pros? Edit: as per the mobo specs - Main Memory • Supports four unbuffered DIMM of 1.5 Volt DDR3 800/1066/1333/1600*/1800*/2133* (OC) DRAM, 16GB Max

  Read the article

• Intel HD Graphics vs NVIDIA Quadro FX 380 PCI-E

  - by Michael

  I recently purchased an Acer Veriton which has an i5-650 processor, Windows 7 Pro (64 bit) and Intel HD Graphics listed as the video card. I also purchased a PNY nVIDIA Quadro FX 380 PCI-E card for improved picture and home video viewing and editing. I have already replaced the original 300 wattt power supply to a 430 watt Antec Truepower I had on hand and boosted the RAM to 8 gigs from the original 4. Question 1) Am I getting any improvement in visual quality or system speed with the Quadro or is it a waste of money and I should just save up to buy a bigger video card? This card was on sale for $115. If I am getting improvement then I need to ask another question. Question 2) Instructions for the Quadro installation are as follows... 1--Uninstall the existing VGA driver. -Remove the existing Display Driver via "Add or Remove Porgrams". -Shut down your computer. 2--Remove your Existing Graphics Board (or Disable Integrated 3D Graphics Controller). skipping instructions on how to remove existing graphics board -Systems with integrated (also know as on-board) 3D graphics may require you to disable the integrated 3D graphics system. Consult the owners or vendor manual that came with your PC on how to properly do this. So is the Intel HD Graphics considered a 3D graphics controller? If so should I just contact Acer or can anyone give me instructions? Thanks in advance for any help.

  Read the article

• Why does my simple Raid 1 backup storage perform really slow sometimes?

  - by randomguy

  I bought 2x Samsung F3 EcoGreen 2TB hard disks to make a backup storage. I put them in Raid 1 (mirror) mode. Made a single partition and formatted it to NTFS, running Windows 7. For some reason, accessing the drive's contents (simply by navigating folders) is sometimes really slow. Like opening D:/photos/ can sometimes take several seconds before it starts showing any of the folder's contents. Same applies for other folders. What could be causing this and what could I do to improve the performance? I remember that there was an option somewhere inside Windows to choose fast access but less reliable persistence operations (read/write). It was a tick inside some dialog. At the time, it felt like a good idea to take the tick away from the option and get more reliable persistence but slower access, but now I'm regretting. I'm unable to find this dialog.. I've looked hard. I don't know, if it would make any difference. Oh, and I've ran scan disk and defrag on the drive. No errors and speed isn't improved.

  Read the article

• Slow manipulation of netfilter rules

  - by Ole Martin Eide

  I have a script maintaining gre tunnels and firewall rules using the "ip" and "iptables" tools. Setting up hundreds of tunnels, and adresses per interface runs just fine. Takes less than 0.1 second per interface, however when I get around to do the firewall rules everything slows down spending 0.5 per insertion. Why is it running so slow? What can I do to improve the speed? It seems like I could try ipset instead, but I really feel there is something wrong with the kernel or something. The interesting thing is that the first 10 rules runs fast, then it slows down.. mybox(root) foo# iptables -V iptables v1.3.5 mybox(root) foo# uname -a Linux foo 2.6.18-164.el5 #1 SMP Tue Aug 18 15:51:48 EDT 2009 x86_64 x86_64 x86_64 GNU/Linux mybox(root) foo# cat test.sh #!/bin/sh for n in {1..100} do /sbin/iptables -A OUTPUT -s ${n} -j ACCEPT /sbin/iptables -D OUTPUT -s ${n} -j ACCEPT done mybox(root) foo# time ./test.sh real 1m38.839s user 0m0.100s sys 1m38.724s Appriciate any help. Cheers!

  Read the article

• PXELinux and compressed kernels/images

  - by Yvan JANSSENS

  Is it possible to boot compressed kernels with a compressed initrd with PXELinux? First, a little background: We created a custom Linux distro, for diskless OpenCL computing nodes. We want those nodes to fetch their OS from the network. Our Distro is composed out of a kernel (duh) and a large initrd which is loaded into RAM and everything is executed from there. We chose to run everything off the initrd for two reasons: NFS was not an option to serve the filesystem's extra contents Fast file access from RAM. No persistent storage needed, data and config is pulled dynamically through a SOAP service. Now our initrd is about 450M in size. At our network speeds, it takes about two to three minutes to load a single client. Will compression speed up te downloading, and if yes, which one should be used? Is LZMA supported by PXELinux, or do we need to stick to bzip2 or gzip? Because of the 2-3 minutes loading time, booting 15 nodes over the same network link takes quite a lot of time. We decided not to use hard drives or CD/DVD drives, for financial reasons (cheapest HDD @ €30 times 15 is a lot of money saved ;-) ) So, our question is: what compression options are available for this setup? And how do we do this? Thank you for your time! Yvan Janssens

  Read the article

• What is the fall off of subsecond throughput on Ethernet Network Interfaces

  - by Kyle Brandt

  On a network interface, speeds are given in term of data over time, in particular, they are bits per second. However, in the uber-fast world of computing -- a second is kind of a really long time. So for example, given a linear falloff. A 1 GBit per second interface would do 500MBit per half second, 250Mbit per quarter second etc. I imagine at certain units of time, this is no longer linear. Perhaps this is set by ethernet frequencies, system clock speeds, interrupt timers etc. I am sure this varies depending on the system -- but does anyone have more information or whitepapers on this? One of the main reasons I am curious is to understand output drops on interfaces. Even if the speed per second is much lower than the interface can handle -- perhaps there are spikes that cause drops for only small numbers of milliseconds. Perhaps various coalescing would hide this effect -- or perhaps increase it on the receiving interface? Do queues make a difference here? Example: So given if this is linear down to the MS we would have 1Mbit/MS, and if Wireshark isn't distorting what I see, should I see drops when I have a spike beyond 1Mbit?

  Read the article

• What are the replacement options for an IDE hd for a DOS based system?

  - by dummzeuch

  I have got a few "embedded" systems running MSDOS 6.2 which boot from and store data to IDE hard disks. Since these drives are nearing their end of life, the question arises how we can replace them. The requirements are: DOS must be able to install and boot from these drives. They must be able to sustain heavy (mostly) write access. If possible, they should be able to survive moderate vibrations (not too bad since the current hds have survived several years of that) I considered the following options so far: other ide hard drives: Unfortunately modern IDE drives are too large so DOS cannot boot from them even if I create small partitions. Older IDE drives are just that: old, so they are probably not the most reliable ones any more. SSDs: There are a few SSDs with IDE interface available. I have not yet tried them. Does anybody have any experience with them? They look like the ideal replacement provided that DOS can boot from them and that writing speed does not deteriorate too much (the old hds are no race cars either). Compact Flash: There are adapters for using CF with IDE controllers and they work fine. DOS can boot from them and they have no problems at all with vibrations. What I am not sure about is their durability. DOS uses FAT so some very few sectors are written every time the medium is being written to. IDE to SATA converters: I have no idea whether they are any good. Has anybody tried them? It might be an option to use one of these to connect an SATA SSD to the system. Are there any alternatives that I have missed? (We are working on replacing these systems, but it will still take a few years.)

  Read the article

• file read performance degrades as number of files increases

  - by bfallik-bamboom

  We're observing poor file read IO results that we'd like to better understand. We can use fio to write 100 files with a sustained aggregate throughput of ~700MB/s. When we switch the test to read instead of write, the aggregate throughput is only ~55MB/s. The drop seems related to the number of files since the throughput for read and write are comparable for a single file then diverge proportionally as we increase the number of files. The test server has 24 CPU cores, 48GB of memory, and is running CentOS 6.0. The disk hardware is a RAID 6 array with 12 disks and a Dell H800 controller. This device is partitioned with ext4 using the default settings. Increasing the readahead (using blockdev) improves the read throughput significantly but it still doesn't match write speed. For instance, increasing the readahead from 128KB to 1M improved the read throughput to ~145MB/s. Is this a known performance issue in our OS/disk/filesystem configuration? If so, how can we tell? If not, what tools or tests can we use to further isolate the issue? Thanks.

  Read the article

• Can I charge USB devices from a powered hub that isn't connected to a PC?

  - by Anodyne

  This will probably sound familiar to most of you... In my home, we have a whole bunch of devices that can be charged via USB (two iPhones, a BlackBerry, an iPod Touch, etc ad nauseam). We also have a bunch of USB chargers, each of which has a single USB port on it. I'd like to have something permanently connected to AC power with at least 4 USB ports on it, so we can just plug devices in and don't need to go looking for a free outlet. So here's the question: if I buy a powered USB hub, will that do the job even if I don't connect it to a PC? Ideally if you have a hub that you can personally verify will be suitable, let me know the manufacturer and model :-) Thanks in advance! EDIT: The solution I eventually went for was this: Kensington 4-Port USB Charger for Mobile Devices (Europe) There's also a US version here: Kensington 4-Port USB Charger for Mobile Devices (USA) It arrived yesterday, so I used it to charge the following devices, all at the same time, overnight last night: 32GB iPhone 3GS 16GB iPhone 3G First-generation iPod Touch Kensington Portable Power Pack for Mobile Devices I can't say anything about the charging speed (as I left it overnight) but all devices were fully charged this morning.

  Read the article

• Throughput and why do ISPs sell too much bandwidth?

  - by jonescb

  I hope the question made sense how I worded it. :) I've been wondering, maximum theoretical bandwidth is measured as RWIN/RTT (Window size / round trip time) Source 1 and Souce 2 So if a major city only 100 miles away gives me a ping of 50ms, and I have the default 64kb TCP window size then my maximum throughput will be 12.5Mb/s. Everything further away would give me a higher ping and therefore a lower throughput. Is there any reason to buy something like FiOS with a 50Mb/s or greater connection? Will you ever be able to reach that kind of speed? I know you can increase the TCP window size to increase throughput, but it has to be at both ends which is a deal breaker because you can't control the server. I'm assuming other network protocols like UDP aren't quite as affected by latency as TCP is, but how much of overall network traffic does non-TCP make up vs TCP. Am I just misguided about how throughput works? But if the above is correct, then why should a consumer like me buy way more bandwidth than can be realistically used. Maybe the only reason is for downloading multiple things at once, or one thing from multiple servers/peers?

  Read the article

• Fake demostration software for command line

  - by Joe

  I'm looking for some software that would be useful for giving demonstrations. I regularly have to show the effects of scrips ect to classes while talking about their effects, and equaly regularly I have finger trouble and have to rewrite various commands - wasting class time and general energy. I'd like to be able to record a sequence of commands in advance, and then play them back at the speed of my choosing. So I might have a file that containes the commands: echo "hello world!" ls ls -l ls -l | sort I'd like to be able to play these commands back by typing similar ones in. So I'd have a blinking command prompt and if I typed 'echo "hxxx' the command prompt would read home$echo "hell and if I typed any other letters the terminal would fill up with the remainder of the command until I press enter, when it executes the command. The point is that even if I screw up the command when typing it, the command that I'd prepared in advance would be executed. My question is - does similar software exist for giving demonstrations? or even, is this an easy thing to script up...? EDIT - two quick things first of all I'm on osx - but it would be nice to get a general solution for other people who arrive here from google. and second a lot of the comments/answers are concentrating on, in effect, making it fast and easy to enter long commands by means of hotkeys and the like. Actually I'd like it to at least look like I'm typing live - that's why I put in the bit about the one-to-one keymapping, but I don't think I explained that quite as well as I could have...

  Read the article

• Windows 8 install from USB freezes

  - by Rafael Almeida

  I'm trying to install Windows 8 from an 8GB Kingston Data Traveler. I'm currently using the Windows 7 USB DVD Download Tool to put the iso into the flash drive. It copies the files, but in the end it says it 'had a problem with bootsect' and could not make the flash drive bootable. This seems to be because my current system is Windows 7 32bits, and the bootsect.exe in the ISO is a 64-bit executable. Then I downloaded the 32-bit bootsect.exe and made the drive bootable by running: bootsect /nt60 E: /mbr Then I restarted and managed to boot via the flash drive, but now everything is very slow. It takes about two minutes for the initial black screen with the Windows logo and the spinner go away, then it goes to a purple-ish blank screen that stays on for about five more minutes and then it finally shows a dialog asking for the installation, date/time and keyboard languages. I input then, click "Install Now" and it takes about three more minutes with a "Setup is starting" screen. After that, the PC apparently reboots, the CPU fan speeds up considerably, and there's no video and nothing more happens even after more than ten minutes. What is happening? I already tried using another USB port and even installing from a Samsung G3 Station 2TB external hard disk, but the same thing happens. The file transfer speed to the Kingston drive was about only 3 megabytes per second.

  Read the article

• Slow, choppy video playback with nVidia 8600GT

  - by user5351

  I have an nVidia 8600GT card (made by EVGA) on a machine with Windows Vista (AMD Athlon X2 processors) and four gigs of ram. It runs pretty good, but I have had some slow/choppy/stuterring video playback issues whenever watching flash videos on Youtube or other sites. The problem is there with both Firefox and IE flash videos, but is maybe worse with Firefox. I also tried Linux with nVidia's binary drivers and it was about the same. I downloaded EVGA precision which allows me to control stuff like the fan and clock speed. The card's temp (in both Vista and Linux) is usually at 66C when idle (not playing a game or watching anything). It goes up a little when watching a video (maybe 68-72C). Any ideas on how to fix this? UPDATE: The issues are both with full screen and embedded flash videos. I have Flash 10.0.32.18 (always make sure I use most recent for security), and the CPU is an AMD Athlon 64 X2 Dual Core Processor 4000+ at 2.11 GHZ. The current GPU driver installed is the most recent GeForce one from last July.

  Read the article

• What does the 'Burst Rate' stat mean in HDTune?

  - by UpTheCreek

  I recently upgraded my laptop's v slow hard drive to a seagate momentus 7200. Everything is working fine, but I'm a bit confused by these benchmark results: The burst rate is significantly less than the Maximim transfer rate, and not much higher than the normal minimum (if you ignore the spikes). What's going on here? On the HDtune website it defines Burst Rate as: ...the highest speed (in megabytes per second) at which data can be transferred from the drive interface (IDE or SCSI for example) to the operating system. Which begs some questions... e.g. if this is the highest, then how did the bechmarking tool record the 103MB/sec maximum? And if this really is the true maximum, then where is the bottleneck? The laptops SATA interface is on an Intel 82801GBM southbridge controller. When I check in hardware manager, I see that it's driver is iaStor.sys from 2005. Maybe that's the issue? I'll look for a newever version, but any insights would be appreciated. Thanks

  Read the article

• Why am I unable to mount my USB drive (unknown partition table)?

  - by Pat

  I'm a real newbie to linux. Anyway the problem is that my USB doesn't get recognized anymore which is really annoying because I need information from it. I've read like a zillion threads how to manually mount it but I really can't it to work. I hope it's just some easy, stupid problem where any of you could help me out quickly.. Here is the syslog: kernel: [ 6872.420125] usb 2-2: new high-speed USB device number 11 using ehci_hcd mtp-probe: checking bus 2, device 11: "/sys/devices/pci0000:00/0000:00:1d.7/usb2/2-2" kernel: [ 6872.556295] scsi8 : usb-storage 2-2:1.0 mtp-probe: bus: 2, device: 11 was not an MTP device kernel: [ 6873.558081] scsi 8:0:0:0: Direct-Access SanDisk Cruzer 8.01 PQ: 0 ANSI: 0 CCS kernel: [ 6873.559964] sd 8:0:0:0: Attached scsi generic sg3 type 0 kernel: [ 6873.562833] sd 8:0:0:0: [sdc] 15682559 512-byte logical blocks: (8.02 GB/7.47 GiB) kernel: [ 6873.564867] sd 8:0:0:0: [sdc] Write Protect is off kernel: [ 6873.564878] sd 8:0:0:0: [sdc] Mode Sense: 45 00 00 08 kernel: [ 6873.565485] sd 8:0:0:0: [sdc] No Caching mode page present kernel: [ 6873.565495] sd 8:0:0:0: [sdc] Assuming drive cache: write through kernel: [ 6873.568377] sd 8:0:0:0: [sdc] No Caching mode page present kernel: [ 6873.568387] sd 8:0:0:0: [sdc] Assuming drive cache: write through kernel: [ 6873.574330] sdc: unknown partition table kernel: [ 6873.576853] sd 8:0:0:0: [sdc] No Caching mode page present kernel: [ 6873.576863] sd 8:0:0:0: [sdc] Assuming drive cache: write through kernel: [ 6873.576871] sd 8:0:0:0: [sdc] Attached SCSI removable disk Thanks in advance

  Read the article

• How can I create a macro that acts on a relative reference rather than an absolute reference to cell A1?

  - by Bruce

  I have a master rent statement in an Excel 2007 (macro enabled) spreadsheet that shows all tenants in rows with columns formed by the months. Each tenant then has a separate rent statement sheet like the one below that pulls the data through from the master rent statement and all I do then is to copy the last 4 columns to the right and add them to the right, just renaming the month labelled as ‘rent due’ with the current month and then hiding the previous last 4 columns to the left so that the statement always shows the previous month's activity and the amount due for the current month: I used a macro to speed up the creation of these statements, but then found that in some cases the result was wrong and needed major correction because the macro use absolute references i.e. its starting position was relative to cell A1 whereas some of my rent worksheets commence from a different column and in some cases from a different column and a different row. I have tried recording the macro with 'Use relative references' but when trying to use the macro it only gets part way through its operation before it stops and the message appears: Run time error '1004' Application defined or object defined error with the option to End or Debug or go to Help and then I'm stuck as I don't know how to debug and work in VBA or understand what has gone wrong. I want to record a single macro that always remains relative to the last 'Total Due' column heading (in the sample, it’s cell FF3 but on another worksheet could be cell GA26) and thus enables me regardless of where on the worksheet the rent statement is placed to add through my recorded macro a further four columns with updated dates and a repositioned 'Total Due' summary (in the sample in cells FE23 and FF23). The contents of cells FE23 and FE22 are always the same number of rows from the 'Sample Rent Statement, Service Charge and Sub Total' rows. I've searched on the web and in the help files of Excel 2007 but have been totally stumped by this, so currently I have to re-record a quantity of macros each month to cover all of the permutations of the worksheets in my Excel rent workbook, which is starting to become pointless in terms of saving time. Does someone know a solution to this problem please?!

  Read the article

• after building in more ram, bios/debian does nothing [closed]

  - by derty

  My private server has 2x1gb Ram working with a 64bit Debian and an Q6600 Intel. This runs 2 virtual mashines on it each one recives 512mb RAM. Which you can immagine is a bit tight for the hole system. Now i got 2x2gb ram from a friend. I'm not sure if thery are clocking at the same speed, but i'm sure my power adaptor is not on his limit and can handle that. So there are 2 ram sockets left at the mainboard. I shuted down the system and build in the 4 gigs and looked what happen. After pressing the start button, everything gets noisy as known BUT the screen shows nothing, not even the bios stuff it usally does. Why isn't the system booting? I can immagine that it does not direkt link between booting debian and the bios not showing a thing. Or is it Grub? I mounted the system disk, and i can see it, switch folders write stuff with "vim" it does not seems like there is a problem.

  Read the article

< Previous Page | 745 746 747 748 749 750 751 752 753 754 755 756  | Next Page >