x5670 double QPI link

LaCuNa

Limp Gawd
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Jun 3, 2014
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Hello fellow geeks, what benefit does an x5670 processor with double QPI links have compared to a similar i7 processor with only 1 QPI link?
 
The benefit is that it can run in dual-socket motherboards. The first QPI path is for connecting to a chipset, and the second one is for connecting to another (identical) processor installed in the same motherboard so that they could work together.
 
How do these x56xx work when using 2 processors that aren't "matched" ?

I only ask because I got a x5680 and in the future it may be nice to have a 2nd but I'm not sure the +/- if they're "matched" or not.
 
ToddW2,

Here's the Intel's documentation about your question (pages 25-26). A brief rundown:
1) Both CPUs must have similar TDP;
2) Both CPUs must have similar QPI and RAM speeds;
3) Both CPUs must have similar number of cores and threads;
4) Both CPUs have to be based on a similar micro-architecture;
5) Stepping does not matter;
6) Clock speed does not matter, either.

It turns out you won't be able to mix your X5680 with any other lower-end Xeon because the closest CPU to yours in the Xeon tier list is the X5675 which comes with 95W TDP.
 
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Good info, and glad you posted those 1-6 here for all to see in the future.

I assume I can always get a 2nd x5680, and your suggestion of the x5675 was another that would work but isn't the same, correct?

For others: The x5680 is a 130w CPU.

Todd
 
Probably I wasn't clear on it, but I think the X5675 wouldn't work together with your X5680 just because the X5675 is a 95W TDP part and your X5680 is a 130W TDP part and that contradicts the first statement I have posted above. Anyway, if was going for a dual-socket setup myself, I would be getting identical CPUs anyway and I suggest you do too. :)
 
I ran a x5660 and a x5650 in an Asus dual socket.
I found when all cores were working on 1 work unit from folding at home they worked at the slower CPU speed.
When running 12 work units, 1 WU per core, they worked at rated speed Running.BOINC

If I remember right in an EVGA SR2 a team member was running a hex core and a quad core for 10/20 cores/threads.
 
I ended up snagging a matched pair, and using the 3rd for another project :)
 
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