Core 2 Quad Threading Question

[dguy6789]

Hello

The Core 2 Quad is two Core 2 Duos strapped together. That is to say it is a pair of monolithic dual core chips. Each pair shares level 2 cache. In a Yorkfield, 2 cores get to share 6MB and 2 other cores get to share 6MB.

My question is this: For programs that run two threads, is it faster for both threads to run on the two cores that share cache, or is it faster for each thread to run on separate pairs so that they could each have access to more level 2 cache each at the sacrifice of interconnect speeds?

 

[faxon]

it would depend greatly on the application running. if the data in the cache is information which can be utilized equally by each core, but doesnt take up the whole cache, it would make more sense to store all the data on one core and process it there, leaving the other cores + cache open to run other things. if the program is processing 2 separate data sets at the same time though, it might make sense to run one on one out of one L2 and the other one off the other, assuming again that the data required doesnt all fit in a single 6mb cache

 

[dguy6789]

Makes sense. It would be interesting to see if some cpu affinity settings affected game performance at all for dual threaded cpu limited games.