neither cpu is too impressive, but i would go with 800eb if i were you.
the p3-1000 is supposed to be a bit faster on boards with intel chipsets. but sis630 is a slower chipset, so its expected to make 100fsb a more noticeable bottleneck, and put the 1ghz at disadvantage.

Wow, never expected to get an answer so fast.

So, the 800EB is a little bit faster. Thanks for the answer.

Also, I have a slotket but I don't know what brand or model it is. I want to put the P3 1GHz in a 440BX motherboard. Is a BCM QS440BX with Slot 1. Can be done?

Well, i've changed the processor and, nothing. Windows doesn't start. I guess I have to reinstall Windows, because Memtest86 and Damn Small Linux are running fine.

See if that 1000 will run at 133, good chance it will.
The 800EB is probably faster in most cases since it's a 33% faster FSB versus a 20% faster clock.

The 800EB doesn't work very well in the PCChips, in Windows there are random lockups and bluescreens, and Linux runs really slow.
The 1000 with the slotket doesn't work either, sometimes the pc doesn't boot at all.

Also, i've tested the 1000 at 133 but can't change the multiplier, so the computer doesn't boot. Same thing happens when put the 800EB at asynchronous memory (133/100).

So I left the computers with their original processors.

Thanks anyway.