On board cache

[JohnB299]

Is there a noteable performance difference in cache size on different cpu chips? in example the 2500 with 640k total and the 2400 with 384k total? Is this even important?
Thanks

 

[Mephistopheles]

Yes, cache is important. But you have to think that AMD considered that when rating their processors... and they considered it generously.

When increasing L2 cache from 256KB to 512KB, AMD already increased Barton's PR by 300 points for the same clock as the T-bred. However, in the real world, the added cache doesn't help that much.

The L2 caches for several non-server processors on the market now range from 1MB (for Banias ) through 512KB (for Barton and Northwood) and to 256KB (T-breds, Palominos, Willamettes...). But don't compare them by numbers, they all use different architectures. The only scenario in which you might compare them by numbers is when one architecture gets its cache doubled - and even then, you can only compare inside that architecture's family.

 

[soundwave5]

Most definatly there is a difference probably the best examples would be the Intel Celeron line of processors. Since the Celerons only have 128k of L2 cache this has a great impact because even at 2.2 Ghz the Celeron performence wise only amounts to the performence of maybe a P4 1.6 (approx). Since the Atholon XP's and the Northwood P4's have a total of 512+ k of cache they are able to reach higher performence levels.


Soundwave

 

[rubikian]

Cache need to be bigger nowadays because the programs are getting larger now. But if cache is too large, you are not using it as cache and treating it as main memory.

 

[JohnB299]

thanks for all the replys!

 

[reever2]

Bigger L2 caches for AMD dont help it that much since its made to use its large L1 cache at higher speeds, like how consoles use <32mb VRAM but dont suffer a penalty because its running like 36gb/sec

Bigger L2 caches on Intels matter a lot, since they depend more on L2 than L1, P4's with lower than <512kb of cache suffer a lot