How do I calculate clock speed in multi-core processors?
- by NReilingh
Is it correct to say, for example, that a processor with four cores each running at 3GHz is in fact a processor running at 12GHz?
I once got into a "Mac vs. PC" argument (which by the way is NOT the focus of this topic... that was back in middle school) with an acquaintance who insisted that Macs were only being advertised as 1Ghz machines because they were dual-processor G4s each running at 500MHz.
At the time I knew this to be hogwash for reasons I think are apparent to most people, but I just saw a comment on this website to the effect of "6 cores x 0.2GHz = 1.2Ghz" and that got me thinking again about whether there's a real answer to this.
So, this is a more-or-less philosophical/deep technical question about the semantics of clock speed calculation. I see two possibilities:
Each core is in fact doing x calculations per second, thus the total number of calculations is x(cores).
Clock speed is rather a count of the number of cycles the processor goes through in the space of a second, so as long as all cores are running at the same speed, the speed of each clock cycle stays the same no matter how many cores exist. In other words, Hz = (core1Hz+core2Hz+...)/cores.
