RE: seti@home
Fri, 16 Jul 1999 04:13:11 -0700 (PDT)

J W [] wrote:
>My Celeron 300 is 63 hours, so that makes it equivalent to something
>like a PII 115. Can the small cache really cut my speed down to a third?

Potentially, yes. The Celeron loses over the PII by having a smaller cache, but gains because the cache runs at the full clock speed, whereas the PII's cache runs at half the clock speed with a 32k(?) L1 cache running at the chip's clock speed. As a result, on any program which uses a lot of tight code, the Celeron will be at least as fast as the PII, because it can all fit in the cache... but when you're accessing a lot of data or a lot of different routines in the code, the PII drops from a 450MHz L1 cache to the 225MHz L2 cache, whereas the Celeron drops from the 300MHz L1 cache to 66MHz system memory. Obviously the PII takes the L2 performance hit well before the Celeron takes the system memory performance hit, but when the PII is running from L2 cache and the Celeron is running from system memory the Celeron will be much, much slower.

Seti has a fairly large dataset, and it spends a lot of time in Windows drawing the bars on the screen, so it's not surprising that a Celeron is slower than a PII.