p4 cache 512 or 256?

[Willy]

Hi all
is this the correct forum for that question?



i made some searchs and found 2 models of intel p4 processor.
the difference is the memory cache (256 in regular e 512 in class A)
what is the difference?which is the best for video aplications?
thanks n help

[vcdfreak]

The following shows that CPU with more cache can be benefited when it comes to encoding:

http://www.tomshardware.com/cpu/02q2/020402/p4_2400-10.html

I bet the non-512K version will be phased out soon, as the 512K version draws closer to the performance of a Athlon XP.

Usually more cache means better performance. Look the the "128K" version of 1.7GHz P4, viz., Celeron 1.7GHz. It's just pathetic.


It goes like this, programs and data running in the processor are stored partially in the register(fastest), L1 cache, L2 cache, then the complete copy is stored in the physical memory(slowest). Since computer programs are huge nowadays, they are mostly saved in L1 cache, L2 cache and physical memory. Since the physical memory is slow compared to L1, L2, they are copied to L1, L2 and see if there is a chance that the data/program codes stored might be reused. If there is a reuse and they can be found in L1, or L2, they will be channeled back to CPU instead of loading from the slow memory.

Nowadays, L2 cache is at the same speed as the CPU. Compared to the RAM, RDRAM, DDRRAM or SDRAM, they are still a lot faster. The bigger the size of the cache, the higher the chance the data that are to be reused can be found there. So why settle for less cache? The 256K cache version are made when the chips manufacturing process is not as good. The 512K version is the improvement version probably seeing the threat from AMD Athlon XP processors. Now Intel can cramp more cache into the chips after moving .13um manufacturing process.

The following benchmark also shows that faster RAM can boost encoding performance:

http://www.tomshardware.com/mainboard/02q2/020501/ddr400vsrambus-04.html


Hope this helps.

[Willy]

ty my friend..now i know whatis the best choice!!!
thank u very much!!!