L2 cache

[YEA_PC_PHONICS]

okay so a main reason the upper coroe's are good is huge L2 right. well i found this from along time ago. why has it changed?

AMD are just faster chips. The P4 is too slow because of the large L2 Cache. Since AMD hasnt brokent he 256 mark they are alot faster. I think Intel has learned from their mistake though and brought the L2 Cache from 512 back down to 256.

 

[TonyBAMF]

Thats becuase that is wrong
L2 Cache is your friend

The large upper L2 cache is a reason the C2D is faster, but deffiently not the only one, many new designs came in the making of such a good CPU

 

[34erd]

okay so a main reason the upper coroe's are good is huge L2 right

No... that may add to performance a bit but it doesn't make a huge difference.

well i found this from along time ago. why has it changed?

It hasn't, that poster was wrong. Larger cache may make higher cache latencys but it wont make a CPU with larger cache perform worse. But then a larger cache doesn't add alot to performance in its self.

 

[Geoff]

The large upper L2 cache is a reason the C2D is faster, but deffiently not the only one, many new designs came in the making of such a good CPU

No... that may add to performance a bit but it doesn't make a huge difference.

Exactly. The Pentium D 9xx has 4MB of L2 cache, but it still wasnt considered that great of a performer. Especially since AMD X2's performed much better with only 1MB of L2 cache.

 

[apj101]

okay so a main reason the upper coroe's are good is huge L2 right

well thats not false, but it would be better to say its a ombination of the size, and the intelligent look ahead, that makes the cache of c2d so good.
plus you quote refers to the P4, however conroe has changed the rules regarding cache latencies a LOT

Exactly. The Pentium D 9xx has 4MB of L2 cache, but it still wasnt considered that great of a performer. Especially since AMD X2's performed much better with only 1MB of L2 cache.

well the amd cache could afford to be slower cause the cpu-memory latencies overall were so much smaller, thus the cache latency and size became less of a factor, unlike for the p-d series et al...

 

[Geoff]

well the amd cache could afford to be slower cause the cpu-memory latencies overall were so much smaller, thus the cache latency and size became less of a factor, unlike for the p-d series et al...

True, I was simply pointing out that just because a CPU has a large L2 cache, it doesn't mean it's a great performer.

 

[Shady]

AMD are just faster chips. The P4 is too slow because of the large L2 Cache. Since AMD hasnt brokent he 256 mark they are alot faster. I think Intel has learned from their mistake though and brought the L2 Cache from 512 back down to 256.

i don't know if what's in the quote is right ... but
i guess what made the AMD X2 faster is the L1 cache
AMD X2 has Higher L1(max 128*2) and lower L2 than the Pentium D or 4
i think this is the key.

 

[Abkrino]

cache why not

guys it's not about cache it's all about design
intel's Itanium 2 has 9 mb cache true that cache increases the performance but the more it's utilized the more the true power of the whole idea of having cache shows while increasing memory in genral increases latency u should divide and conquer with multi core tech already shipping this should push the cache size greater than 16 mb i expect in 2007-2008