disable cores, get cache?

[Anosh]

I have a i7 920 (1366) and the cache structure (according to CPU-Z) looks like this:
L1 Data 4 x 32 KBytes , 8-way
L1 Inst. 4 x 32 KBytes , 4-way
L2 4 x 256 KBytes , 8-way
L3 8 MBytes, 16-way

And I was wondering if I would to disable half the cores (2 out of 4) would the remaining cores get more cache per core? And could it have a positive effect in games since CPUs with larger cache (ie generation before nehalem) perform better in games.

From what I can recall only the L3 cache is outside of core die and therefore only this cache stays active when a pair of cores are disabled?

 

[hans007]

yes. i am pretty sure it would work just like other cpus with disabled cores on die.

phenom II x2 the 2 remaining cores share the L3 cache, same with celeron Ms which are based on a dual core Core 2 duo with 1 core disabled.

 

[dguy6789]

In theory this would give the fewer cores more L3 cache, but it most likely wouldn't improve your gaming experience. By having those cores available, they can handle any task that might be called from the operating system, leaving the cores that are running your game to keep running the game without interruption. The less cores you have, the more of a performance hit you get when the OS(or any other program that may be running) needs CPU cycles while you're playing a game.

 

[iCyborg]

And I was wondering if I would to disable half the cores (2 out of 4) would the remaining cores get more cache per core? And could it have a positive effect in games since CPUs with larger cache (ie generation before nehalem) perform better in games.

Well, yes, in theory, but I believe L3 isn't fairly shared between all active cores, so if 2 cores are mostly idling, the other 2 can use more L3 than their 2mb share, in other words, I doubt you'd see a meaningful positive effect.

 

[SHAQ]

You could try it in a game that only uses 2 cores. Almost every game released in the last year supports 4 though. Play Mount and Blade with 2 and 4 cores. Play it with different amounts of soldiers on the screen during battles by editing the cfg. I think Warband has a demo. Mount and Blade only supports one core though, but it is very CPU limited and I think that would be the best test since the mount of soldiers on the screen can be set.