funny i have that situation also, i have a computer with a celeron (d i think...) at 2.53 ghz, i wanted to upgrade so i purchased a pentium 4 3.0E with an 800 fsb, since the socket was 478 i didnt think that it mattered so i plugged it in and found that with a 400 or 533 fsb the p4 ran at half its said speed, 1.5 ghz... i wasnt sure if this was an upgrade so i went back to the celeron, i know nothing about performing benchmark tests, except that they are possible.
   
  subsequently i purchased a computer from a friend that had a p4 at 2.8 ghz with a fsb of 400 or 533, i am not sure why this intel mother board is capable of using either fsb speeds...
  i havent yet figured out if this situation yielded an upgrade but i am curious...also i was wondering if fsb speed was ajustable on all motherboards or some or any at all? 
   
  i dont remember, but fsb ratings may be listed in the mother board bios, on the compaq i have it is called set up i think and is found by pressing a certain button right before the operating system boots...maybe f10?

[log in to unmask]> wrote:
  I have a Compaq computer that uses a socket 478 Pentium 4 1.7 GHz processor with a 400 MHz FSB. I want to upgrade this processor, and I have found 2.8 GHz socket 478 P4, but it has a 533 FSB. Will this processor still work, just at the 400 MHz FSB speed, or are they completely incompatible? Is there a way to find out the speed it will run at with a 400 MHz FSB?

Thanks

Glenn Goodrich


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