AlexZ wrote on Yesterday, 16:51:

CUBX is a 133Mhz FSB board, 1Ghz@133 is the best choice. It may be possible to run it at 500Mhz with 66Mhz FSB. 100Mhz FSB versi […]
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pete8475 wrote on 2026-03-27, 22:08:

I might buy a 100mhz fsb P3-900 and see if I can get that stable at 1.2. That way everything is in spec except agp (this card is fine with 89mhz agp) and it obviously would downclock nicely to 600mhz (66mhz fsb) as well.

CUBX is a 133Mhz FSB board, 1Ghz@133 is the best choice. It may be possible to run it at 500Mhz with 66Mhz FSB. 100Mhz FSB versions suffer from FSB overload at about 900Mhz and higher.

My PIII 900 is enough for the whole Windows 98 era and very early Windows XP (~2002).

fx5900xt is for P4/Athlon XP/Athlon 64 (s754). If you want to max it out in Windows 98 then get Athlon 64 with AGP. GeForce 4200ti is a good match for PIII.

H3nrik V! wrote on 2026-03-29, 06:41:

The thing with 900/100s is that there were never sold many back in the day, I have yet to come across one for a price, I'm comfortable paying ..

That's why I got an extra PIII 900 while they were cheaper. I have also seen 1.1Ghz@100 on sale, but those are even more rare.

The best CPU for this board is the P3 1.4S I have, but this isn't about having the fastest P3.

That CPU isn't quite fast enough so I use a P4 overclocked to 4.75GHZ for the later DX9 era stuff, I just want something a little more versatile for old stuff so I've ordered on ebay a 900 and we'll see if it'll do 600, 900 and 1200mhz.

EDIT - also 133FSB 1GHZ Pentium 3 does work at 500 in this board.

I couldn't find a Coppermine that would reliably clock past about 1100 on my Intel Seattle board. Even the Celeron 1100 that I had would lock up and freeze.
Ended up with a cheap slocket and a pin modded Tualatin 1266.
Eventually moved on the just using my Intel 815 board with the same chip.
It is fast and trouble free.

AlexZ wrote on Yesterday, 16:51:

H3nrik V! wrote on 2026-03-29, 06:41:

The thing with 900/100s is that there were never sold many back in the day, I have yet to come across one for a price, I'm comfortable paying ..

That's why I got an extra PIII 900 while they were cheaper. I have also seen 1.1Ghz@100 on sale, but those are even more rare.

Makes sense. By an incredible strike of luck, I've gotten my hands on a pair of 1.1/100. Both working - for my P2B-DS. (All though a pair of native 1000/100 Slot1 would be even cooler)