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>You will note that, for a given clock speed, the Pentium 3 machines are
>about 50% faster than the new Pentium 4. Newer ain't always better!

It's well known that the Pentium 4 clock speeds aren't comparable to
the Pentium 3, or the AMD Athlon, for that matter. The Pentium 4 uses
a different internal architecture that does less on each clock, but
which Intel claims can be scaled to much higher clock speeds in the

The current Pentium 4 has a large cache line size of 64 bytes vs 32
bytes on the Pentium 3. It also has a smaller level 1 data cache, 8KB
vs 16KB for the Pentium 3. So memory access patterns can have a big
effect on the relative performance of these two CPUs.

The Pentium 4 provides SSE2, a set of additional instructions for
digital signal processing. But unless the application is written to
use it, SSE2 provides no benefit.

Because Seti@Home won't release client source code, we have no way to
know if it can use SSE2, or the earlier DSP instruction sets MMX and
SSE. And we have no way to analyze memory access behavior to see if it
could be improved for the Pentium 4.

I've gotten the distinct impression that the Seti@Home folks have many
more volunteers than they need, so they haven't bothered to optimize
their client software to use our machines (and our electricity) as
efficiently as possible.


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