If I remember correctly the Gigabyte GA-BX2000+ would not run any really fast CPUs at 133 MHz FSB like the Coppermine 1000(133) or the Tualatin P3-S 1400.
The ones with 100 MHz FSB did run flawlessly like the Coppermine Celeron 1100 and the Tualatiin Celeron 1400.
It's not rellay an issue with the motherboard not handling 133 MHz FSB as the P3 800(133) ran fine and I could even overclock to what ever max FSB the motherboard supported when I used a Coppermine 600(133) or similar. It must be some odd timing issue/bug with the combination of high FSB and a really fast CPU.
I used a MSI 6905 Master Slotket and Korea modded Tualatins but I dont think that makes anything any different as the Coppermines suffered from the same issue.
If you can find a Celeron 1400 I think that would be a safe... -ish bet.
If the Slot-T has FSB selection jumpers try forcing 100 MHz FSB. The Tualatin P3-S @1050 is almost as fast as the Tualeron 1400 (and much faster than the Coppermine) and perhaps you can get away with 112 or 115 MHz FSB with either one.
Edit.
112 MHz FSB was the best I managed with the Tualatin P3-S 1400 on the Gigabyte BX2000+ and this ruined my whole i440BX vs i815 vs VIA Apollo Pro benchmarking and CPU scaling project.
P3-S @112 MHz FSB
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Celeron 1400 @112 MHz FSB
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The P3-S wins out but I think the Celeron would fare somewhat better with a faster video card.
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(only some of the game results here, the rest are still screenshots only)
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New PC: i9 12900K @5GHz all cores @1.2v. MSI PRO Z690-A. 32GB DDR4 3600 CL14. 3070Ti.
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