Hi Alan
My system runs with an XP2400 chip under Win XP Pro and does the same thing,
when it starts to process a new work unit it runs at 60% per hour then
within 30 mins or so it drops off to anything between 32% to 40% per hour
(average WU time 2hrs 40mins).
I think if you go to a Pentium 4 you'll have to change the motherboard, as
the CPU pins are different and if you do that go for one with the highest
bus speed, that way it makes upgrades easier in the future.
Hope this helps.
-- 
Ron Atkin.
Peterborough,
UK.
"Alan Browne" <alan.browne@FreeLunchvideotron.ca> wrote in message
news:x5idnasahrH7wODd4p2dnA@giganews.com...

I'm running 3.08 under WinXP on a Celeron at 2.4 GHz.  I may upgrade to
a Pentium IV by simply replacing the chip.

Requesting clarification.  When SETI runs a unit, it completes the first
10% of the unit very quickly (about 1 hour in my case).  After that
first 10% or so, however, the rate of processing falls to about 3% /
hour.  Is there some reason for this?

Can anyone guestimate my performance improvement if I replace the
Celeron with a Pentium IV at the same clock speed?

Cheers,
Alan.