Search Results

Search found 20904 results on 837 pages for 'disk performance'.

Page 283/837 | < Previous Page | 279 280 281 282 283 284 285 286 287 288 289 290  | Next Page >

• Dual booting windows 8/ubuntu 12.04. Grub doesn't appear and machine never boot in ubuntu

  - by black sensei

  i got a new ACER predator AG3620-UR308 which came with windows 8, so i wanted to run ubuntu 12.04.2 on it as a dual booting. To be honest, i've been doing dual booting for a while now so, i did the right thing. the box came with 2TB HDD. so i made 4 partitions with a raw partition just after the windows installation partition I always do manual installation so even if ubuntu didn't detect windows 8, it was ok for me. So i created swap area and finished the installation etc....Grub was install on the only drive there which is sda. After reboot, grub doesn't even come up.So it always boot in windows 8. I did repeat the installation process twice and yield same result. which is weird because this method always works for me so far.Even the laptop am using to write this post is a dual booting windows 7/ mint nadia installed the same way. Is there anything new in windows 8 that i didn't make provision for? Before starting the installation, all i read about was that , windows 8 should be installed first and ubuntu after. I went ahead and disable secure boot from the BIOS and enabled CSM (don't even know what it means) according to Acer custhelp site . I boot from USB and did fdisk -l bellow is the result: ubuntu@ubuntu:~$ sudo fdisk -l WARNING: GPT (GUID Partition Table) detected on '/dev/sda'! The util fdisk doesn't support GPT. Use GNU Parted. Disk /dev/sda: 2000.4 GB, 2000398934016 bytes 255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes Disk identifier: 0x8c361cb5 Device Boot Start End Blocks Id System /dev/sda1 1 3907029167 1953514583+ ee GPT Partition 1 does not start on physical sector boundary. Disk /dev/sdb: 8178 MB, 8178892800 bytes 255 heads, 63 sectors/track, 994 cylinders, total 15974400 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x0006a87e Device Boot Start End Blocks Id System /dev/sdb1 * 2048 15972351 7985152 b W95 FAT32 ubuntu@ubuntu:~$ Can anybody shed some light? thank you in advance

  Read the article

• SIMD Extensions for the Database Storage Engine

  - by jchang

  For the last 15 years, Intel and AMD have been progressively adding special purpose extensions to their processor architectures. The extensions mostly pertain to vector operations with Single Instruction, Multiple Data (SIMD) concept. The motivation was that achieving significant performance improvement over each successive generation for the general purpose elements had become extraordinarily difficult. On the other hand, SIMD performance could be significantly improved with special purpose registers...(read more)

  Read the article

• Organization &amp; Architecture UNISA Studies &ndash; Chap 4

  - by MarkPearl

  Learning Outcomes Explain the characteristics of memory systems Describe the memory hierarchy Discuss cache memory principles Discuss issues relevant to cache design Describe the cache organization of the Pentium Computer Memory Systems There are key characteristics of memory… Location – internal or external Capacity – expressed in terms of bytes Unit of Transfer – the number of bits read out of or written into memory at a time Access Method – sequential, direct, random or associative From a users perspective the two most important characteristics of memory are… Capacity Performance – access time, memory cycle time, transfer rate The trade off for memory happens along three axis… Faster access time, greater cost per bit Greater capacity, smaller cost per bit Greater capacity, slower access time This leads to people using a tiered approach in their use of memory   As one goes down the hierarchy, the following occurs… Decreasing cost per bit Increasing capacity Increasing access time Decreasing frequency of access of the memory by the processor The use of two levels of memory to reduce average access time works in principle, but only if conditions 1 to 4 apply. A variety of technologies exist that allow us to accomplish this. Thus it is possible to organize data across the hierarchy such that the percentage of accesses to each successively lower level is substantially less than that of the level above. A portion of main memory can be used as a buffer to hold data temporarily that is to be read out to disk. This is sometimes referred to as a disk cache and improves performance in two ways… Disk writes are clustered. Instead of many small transfers of data, we have a few large transfers of data. This improves disk performance and minimizes processor involvement. Some data designed for write-out may be referenced by a program before the next dump to disk. In that case the data is retrieved rapidly from the software cache rather than slowly from disk. Cache Memory Principles Cache memory is substantially faster than main memory. A caching system works as follows.. When a processor attempts to read a word of memory, a check is made to see if this in in cache memory… If it is, the data is supplied, If it is not in the cache, a block of main memory, consisting of a fixed number of words is loaded to the cache. Because of the phenomenon of locality of references, when a block of data is fetched into the cache, it is likely that there will be future references to that same memory location or to other words in the block. Elements of Cache Design While there are a large number of cache implementations, there are a few basic design elements that serve to classify and differentiate cache architectures… Cache Addresses Cache Size Mapping Function Replacement Algorithm Write Policy Line Size Number of Caches Cache Addresses Almost all non-embedded processors support virtual memory. Virtual memory in essence allows a program to address memory from a logical point of view without needing to worry about the amount of physical memory available. When virtual addresses are used the designer may choose to place the cache between the MMU (memory management unit) and the processor or between the MMU and main memory. The disadvantage of virtual memory is that most virtual memory systems supply each application with the same virtual memory address space (each application sees virtual memory starting at memory address 0), which means the cache memory must be completely flushed with each application context switch or extra bits must be added to each line of the cache to identify which virtual address space the address refers to. Cache Size We would like the size of the cache to be small enough so that the overall average cost per bit is close to that of main memory alone and large enough so that the overall average access time is close to that of the cache alone. Also, larger caches are slightly slower than smaller ones. Mapping Function Because there are fewer cache lines than main memory blocks, an algorithm is needed for mapping main memory blocks into cache lines. The choice of mapping function dictates how the cache is organized. Three techniques can be used… Direct – simplest technique, maps each block of main memory into only one possible cache line Associative – Each main memory block to be loaded into any line of the cache Set Associative – exhibits the strengths of both the direct and associative approaches while reducing their disadvantages For detailed explanations of each approach – read the text book (page 148 – 154) Replacement Algorithm For associative and set associating mapping a replacement algorithm is needed to determine which of the existing blocks in the cache must be replaced by a new block. There are four common approaches… LRU (Least recently used) FIFO (First in first out) LFU (Least frequently used) Random selection Write Policy When a block resident in the cache is to be replaced, there are two cases to consider If no writes to that block have happened in the cache – discard it If a write has occurred, a process needs to be initiated where the changes in the cache are propagated back to the main memory. There are several approaches to achieve this including… Write Through – all writes to the cache are done to the main memory as well at the point of the change Write Back – when a block is replaced, all dirty bits are written back to main memory The problem is complicated when we have multiple caches, there are techniques to accommodate for this but I have not summarized them. Line Size When a block of data is retrieved and placed in the cache, not only the desired word but also some number of adjacent words are retrieved. As the block size increases from very small to larger sizes, the hit ratio will at first increase because of the principle of locality, which states that the data in the vicinity of a referenced word are likely to be referenced in the near future. As the block size increases, more useful data are brought into cache. The hit ratio will begin to decrease as the block becomes even bigger and the probability of using the newly fetched information becomes less than the probability of using the newly fetched information that has to be replaced. Two specific effects come into play… Larger blocks reduce the number of blocks that fit into a cache. Because each block fetch overwrites older cache contents, a small number of blocks results in data being overwritten shortly after they are fetched. As a block becomes larger, each additional word is farther from the requested word and therefore less likely to be needed in the near future. The relationship between block size and hit ratio is complex, and no set approach is judged to be the best in all circumstances.   Pentium 4 and ARM cache organizations The processor core consists of four major components: Fetch/decode unit – fetches program instruction in order from the L2 cache, decodes these into a series of micro-operations, and stores the results in the L2 instruction cache Out-of-order execution logic – Schedules execution of the micro-operations subject to data dependencies and resource availability – thus micro-operations may be scheduled for execution in a different order than they were fetched from the instruction stream. As time permits, this unit schedules speculative execution of micro-operations that may be required in the future Execution units – These units execute micro-operations, fetching the required data from the L1 data cache and temporarily storing results in registers Memory subsystem – This unit includes the L2 and L3 caches and the system bus, which is used to access main memory when the L1 and L2 caches have a cache miss and to access the system I/O resources

  Read the article

• Webcast - June 27th: Announcing Oracle SuperCluster T5-8: Our Fastest Engineered System

  - by Javier Puerta

  Join us for a live webcast with Oracle Executive Vice President, John Fowler, as he announces the new Oracle SuperCluster T5-8: Our Fastest Engineered System. Learn how the new Oracle SuperCluster T5-8 delivers: Extreme performance through Oracle Exadata, Oracle Exalogic, Oracle’s virtualization solutions, and the world’s fastest servers Highest availability with no single point of failure and 99.999% uptime Highest efficiency with unmatched price/performance and the lowest operating costs A complete engineered system ideal for database and application consolidation and private cloud Register here

  Read the article

• Calgary .NET User Group &ndash; Entity Framework Code First - December 11th

  - by David Paquette

  I will be presenting at the Calgary .NET User Group on December 11th. We will start from scratch in this intro to Entity Framework Code First. We will build a simple application using ASP.NET MVC and Entity Framework and evolve the application to show how we can build scalable applications using Entity Framework Code First. Topics covered will include database initialization, code based migrations, performance profiling and performance tuning. Register at http://www.dotnetcalgary.com/

  Read the article

• Improving Finance Department Productivity at BorgWarner

  Nigel Youell, Product Marketing Director, Enterprise Performance Management Applications at Oracle discusses with Mark Smith, Manager, Financial Reporting Systems at BorgWarner how using Oracle's Enterprise Performance Management System on top of SAP transactional systems at BorgWarner has made significant improvements in the productivity of it finance function and halved the time it takes for to close its books.

  Read the article

• Brute Force Hardware versus Tuning

  - by jchang

  Every now and then, the question is asked “When will servers be powerful enough that performance tuning will not be necessary.” Sometimes I get the impression this was posed not on technical grounds, but rather that ISVs and CIOs don’t like performance specialists. Fortunately (for me) it does not appear that this will ever happen for two principal reasons: 1) hardware and tuning contribute in such completely different aspects that neither can be ignored, and 2) multi-core processors actually introduce...(read more)

  Read the article

• PowerPivot FILTER condition optimizations

  - by Marco Russo (SQLBI)

  In the comments of a recent post from Alberto Ferrari there was an interesting note about different performance related to the order of conditions in a FILTER call. I investigated about that and Jeffrey Wang has been so nice to give me some info about actual implementation that I can share on a blog post. First of all, an important disclaimer: PowerPivot is intended to make life easier, not requiring the user to think how to write the order of elements in a formula just to get better performance....(read more)

  Read the article

• Understanding Dynamic Management Views and Functions in SQL Server 2008

  Performance monitoring and optimization is an inseparable part of a DBA's activities. To optimize a poorly performing system/query or to troubleshoot the performance issues you need to know the root cause. Prior to SQL Server 2005, we had several system tables to monitor the state of the system. SQL Server monitoring made easy "Keeping an eye on our many SQL Server instances is much easier with SQL Response." Mike Lile.Download a free trial of SQL Response now.

  Read the article

• Introduction to SQL Server 2008 Extended Events

  SQL Server 2008 Extended Events are the new low level, high performance eventing system in SQL Server. They use less system resources and provide better tracking of SQL Server performance than previous methods like Perfmon and SQL Trace/Profiler events.

  Read the article

• Getting windows 7 to boot from external hard drive. Using Ubuntu

  - by SMS

  I have Ubuntu 12.04LTS as my current operating system, and I have a Windows 7 iso on a disk. I'm using an external hard drive because my internal hard drive has become damaged. I need to get Windows to install onto my external hard drive (where Ubuntu is as well). The iso disk will not install windows to the hard drive. Can anyone help guide me through the process of getting windows on the external?

  Read the article

• Using a PowerShell Script to delete old files for SQL Server

  Many clients are using custom stored procedures or third party tools to backup databases in production environments instead of using database maintenance plans. One of the things that you need to do is to maintain the number of backup files that exist on disk, so you don't run out of disk space. There are several techniques for deleting old files, but in this tip I show how this can be done using PowerShell.

  Read the article

• Ubuntu 12.10 Live USB BootError

  - by Sivan

  I am a Linux Newbee, running ubuntu 12.04 i386 on a 64-bit machine. Now I just downloaded Ubuntu 12.10 AMD64 iso and made a bootable USB using Startup Disk Creator. I was directed to install available updated packages, which I did install. The Startup Disk was succesfully created. But when I tried to boot from the USB I am getting a BootError message and nothing else. What could have gone wrong?

  Read the article

• Visual Studio 2012 Update 3 disponible et marque la fin des mises à jour pour cette version de l'EDI

  Visual Studio 2012 Update 3 CTP 1 disponible avec des améliorations de performance et plusieurs correctifs de boguesQuelques semaines seulement après la sortie de Visual Studio 2012 Update 2, Microsoft dévoile la prochaine mise à jour de son environnement de développement.L'éditeur vient de publier la Community Technology Preview (CTP) de Visual Studio 2012 Update 3, qui apporte des corrections de bogues, des améliorations de performance et quelques nouveautés.Avec cette troisième version de Visual Studio 2012 Update, Microsoft donne l'impression d'avoir adopté un rythme de mises à jour plus rapide pour l'EDI, axé sur le trimestr...

  Read the article

• How Oracle GRC Applications Improve the Bottom Line

  By spotting anomalies before they incur large losses and limiting exposure to fraud and wastage, organizations save on time and cost spent on errors and remediation, prevent the escalation of risk, and optimize business performance. The session will unveil the latest capabilities offered by Oracle's GRC Applications that help companies grow from managing compliance to optimizing business performance.

  Read the article

• Top Exastack ISV Headlines: Smartsoft, Forbis

  - by Javier Puerta

  Smartsoft's OCEAN Payment Processing Solution achieves Oracle Exadata Optimized status. "Performance is the most important issue for our success in the market and running OCEAN on the Oracle Exadata Database Machine provides customers with extreme performance." - Learn more Banking solution FORBIS Ltd's FORPOST achieves Oracle Exadata, Exalogic and SuperCluster Ready Status. "We are glad to offer our current and future customers the newest features provided by Oracle Engineered Systems to achieve maximum reliability and speed operation." - Learn more

  Read the article

• Is it recommended to apply the new said-great 200 line Linux kernel patch?

  - by takpar

  Hi, Nowadays I'm hearing a lot about the new ~200 line path to Linux kernel that is said makes sensible difference in performance. Now, do anyone has experience on applying this path on his Ubuntu kernel? I also saw an alternative way that claimed has a better result: wget http://launchpadlibrarian.net/59511828/cgroup_patch chmod +x cgroup_patch sudo ./cgroup_patch What do you think this is? Is this validated? I ask this question because I need more performance but I can't risk on stability.

  Read the article

• Management of Windows Azure SQL Databases via PowerShell with REST APIs

  Management of Azure SQL Databases has been greatly simplified by the introduction of the Azure PowerShell module. Marcin Policht describes the principles of dealing with the Azure PowerShell module’s REST APIs directly. FREE eBook – "45 Database Performance Tips for Developers"Improve your database performance with 45 tips from SQL Server MVPs and industry experts. Get the eBook here.

  Read the article

• Different Ways to Restore a SQL Server Database

  This article describes the SQL Server database restore principles for full backups, differential backups and transaction log backups and how to perform the restores to get to a particular point in time. This tip describes SQL Server database restore principles on a database that is using the FULL recovery model. FREE eBook – "45 Database Performance Tips for Developers"Improve your database performance with 45 tips from SQL Server MVPs and industry experts. Get the eBook here.

  Read the article

• Maximizing Throughput with TVPs

  TVPs offer several performance optimization possibilities that other bulk operations do not allow, and these operations may allow for TVP performance to exceed other bulk operations by an order of magnitude, especially for a pattern where subsets of the data are frequently updated. Want to work faster with SQL Server?If you want to work faster try out the SQL Toolbelt. "The SQL Toolbelt provides tools that database developers as well as DBAs should not live without." William Van Orden. Download the SQL Toolbelt here.

  Read the article

• USB hard drive not recognized

  - by user318772

  Until recently I was using the portable USB hard drive in my win 7 laptop and ubuntu laptop. Suddenly now none of the laptops recognize it. This is the message i get by doing lsusb... Bus 001 Device 004: ID 1058:1010 Western Digital Technologies, Inc. Elements External HDD Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub Bus 005 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 004 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 003 Device 003: ID 0b97:7762 O2 Micro, Inc. Oz776 SmartCard Reader Bus 003 Device 002: ID 0b97:7761 O2 Micro, Inc. Oz776 1.1 Hub Bus 003 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub Bus 002 Device 002: ID 413c:a005 Dell Computer Corp. Internal 2.0 Hub Bus 002 Device 001: ID 1d6b:0001 Linux Foundation 1.1 root hub fdisk doesn't show the external hard drive Disk /dev/sda: 80.0 GB, 80026361856 bytes 255 heads, 63 sectors/track, 9729 cylinders, total 156301488 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x0004a743 Device Boot Start End Blocks Id System /dev/sda1 * 2048 152111103 76054528 83 Linux /dev/sda2 152113150 156301311 2094081 5 Extended /dev/sda5 152113152 156301311 2094080 82 Linux swap / Solaris when i do testdisk TestDisk 6.14, Data Recovery Utility, July 2013 Christophe GRENIER <[email protected]> http://www.cgsecurity.org TestDisk is free software, and comes with ABSOLUTELY NO WARRANTY. Select a media (use Arrow keys, then press Enter): >Disk /dev/sda - 80 GB / 74 GiB - ST980825AS Disk /dev/sdb - 2199 GB / 2048 GiB testdisk-> Intel->analyse I get partition error Disk /dev/sdb - 2199 GB / 2048 GiB - CHS 2097152 64 32 Current partition structure: Partition Start End Size in sectors Partition: Read error Here is the output of dmesg [11948.549171] Add. Sense: Invalid command operation code [11948.549177] sd 2:0:0:0: [sdb] CDB: [11948.549181] Read(16): 88 00 00 00 00 00 00 00 00 00 00 00 00 08 00 00 [11948.550489] sd 2:0:0:0: [sdb] Invalid command failure [11948.550495] sd 2:0:0:0: [sdb] [11948.550499] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE [11948.550505] sd 2:0:0:0: [sdb] [11948.550508] Sense Key : Illegal Request [current] [11948.550514] Info fld=0x0 [11948.550519] sd 2:0:0:0: [sdb] [11948.550525] Add. Sense: Invalid command operation code [11948.550531] sd 2:0:0:0: [sdb] CDB: [11948.550534] Read(16): 88 00 00 00 00 00 00 00 00 00 00 00 00 08 00 00 [11948.551870] sd 2:0:0:0: [sdb] Invalid command failure [11948.551876] sd 2:0:0:0: [sdb] [11948.551880] Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE [11948.551885] sd 2:0:0:0: [sdb] [11948.551888] Sense Key : Illegal Request [current] [11948.551895] Info fld=0x0 [11948.551900] sd 2:0:0:0: [sdb] [11948.551905] Add. Sense: Invalid command operation code [11948.551911] sd 2:0:0:0: [sdb] CDB: [11948.551914] Read(16): 88 00 00 00 00 00 00 00 00 00 00 00 00 08 00 00 If possible i want to retrive at least some data from this hard drive. If thats not possible I would like to format it and use it. Any help will be greatly appreciated Thanks

  Read the article

• TechEd 2014 Day 1

  - by John Paul Cook

  Today at TechEd 2014, many people had questions about the in-memory database features in SQL Server 2014. A common question is how an in-memory database is different from having a database on a SQL Server with an amount of ram far greater than the size of the database. In-memory or memory optimized tables have different data structures and are accessed differently using a latch free and lock free approach that greatly improves performance. This provides part of the performance improvement. The rest...(read more)

  Read the article

• The SQL of Membership: Equivalence Classes & Cliques

  It is awkward to do 'Graph databases' in SQL to explore the sort of relationships and memberships in social networks because equivalence relations are classes (a set of sets) rather than sets. However one can explore graphs in SQL if the relationship has all three of the mathematical properties needed for an equivalence relationship. FREE eBook – "45 Database Performance Tips for Developers"Improve your database performance with 45 tips from SQL Server MVPs and industry experts. Get the eBook here.

  Read the article

• Creating Indicator and Gauge Report in SSRS - SQL Server 2008 R2

  SQL Server Reporting Services allows you to embed indicators and Gauges in your report to analyze the data and its state. Indicators are minimal gauges that convey the state of a single data value at a glance and are mostly used to represent state value of Key Performance Indicator (KPI). New! SQL Monitor 3.0 Red Gate's multi-server performance monitoring and alerting tool gets results from Day One.Simple to install and easy to use – download a free trial today.

  Read the article

• Cursor-Killing: Retrieving Recently Modified Data

  Cursors are considered by many to be the bane of good T-SQL. What are the best ways to avoid iterative T-SQL and to write queries that look and perform beautifully? In the next part of an ongoing series, we look at ways to efficiently retrieve recently modified data. FREE eBook – "45 Database Performance Tips for Developers"Improve your database performance with 45 tips from SQL Server MVPs and industry experts. Get the eBook here.

  Read the article

< Previous Page | 279 280 281 282 283 284 285 286 287 288 289 290  | Next Page >