Win2000 shall run well on it.
I'd go TNT2 Ultra, dual Voodoo 2 and dual Katmai on that kind of machine.
To make it the ultimate pre coppermine/Athlon/Geforce setup.

You could install BeOS as part of the dual-boot, or make that a triple-boot, dual cpu (or more) machine are exactly the kind of setup perfect for that OS.
Best graphic card would then be a Voodoo 3 if you want hardware-accelerated OpenGL for Quake 2 & 3.
The web browser is totally obsolete though...

Win2k should run like a dream on there. I used to run it just fine on a single Pentium II 266MHz with 384MB of ram.

the problem with a Voodoo 3 for instance is that the newer V5500 machine i have can do everything a V3 can do , only better, same with putting Katmai's in it (ie, a speed sensitive game is going to respond the same to a Katmai 600 as it would to a Coppermine 800), so the benefit is lost in that case.

400Mhz would mean games like C&C or Grim working better without speed issues (or if there are any , its easier to slow it down), same with the V1 and the extra compatibility it has with earlier Glide games at least that is my thinking behind it.

400MHz is a pretty fine spot, I used a 333MHz P2 @ 417MHz for years and was pretty happy with it.
Only with Quake 3 it began to be a bit sluggish, with its TNT, it played in 800x600 med details max.

thats really it , for games like Quake 3 , Alice , NOLF etc, I can use my 800Mhz Coppermine/V5500 machine which it plays very well for the most part.

the real choice is between keeping this as a dual CPU machine, or swapping parts around as I previously stated, both choices have their merits.

Darkman wrote:

thats really it , for games like Quake 3 , Alice , NOLF etc, I can use my 800Mhz Coppermine/V5500 machine which it plays very well for the most part.

the real choice is between keeping this as a dual CPU machine, or swapping parts around as I previously stated, both choices have their merits.

For gaming, the only game that'll use the second CPU is Quake 3, and dual 400MHz is too low for it, so ...
I actually own a dual P2 400, but I'll put my Slot A in the case instead.

hence part of the reason why I want to use it on the 800Mhz machine, the BX6 in the other machine doesn't officially support the Coppermine, wheres this motherboard does (at least according to Gigabyte's website) , just makes things a little easier and more logical , at least for me.

it also means I won't have to run NT or 2K on this since it won't be any use (well I might still install NT just for the sake of it), the other machine already has a 98/2K dual boot.

If it was me I would put the P2 400 in the Abit BX6. As you say it was one of the defacto CPU's for a long time and temperature isn't much of a worry.
And a duel 800 Mhz Coppermine is sexy. Not that useful but sexy.
To me, Win2k seems a bit slower in games then 9x so the 2nd CPU may offload some windows extra resources and bring it up to 9x speeds. Not sure about that though, I know 2k was pretty basic at CPU resourcing. and of course you can always duel boot into 9x and have the 2nd CPU ignored anyway.

interestingly I did install Win2K on a 2nd hard drive (added the 80GB hard drive , on top of the 20GB one already present), and after trying out Quake2 on both I found that , at least in OpenGL mode , Win2K was about half the speed , which is very odd because on the other machine there is almost no difference in that game, and some games actually run faster , its most likely the Rage Pro drivers , if I remember correctly, ATI weren't that great at releasing good drivers back in the day. I do really like the 2D quality on this card though , its no worse than the Voodoo 5 I would say, certainly less blurry than the GF2Ti .

the issue now is actually finding a 2nd 800Mhz PIII , the 133Mhz variety is everywhere and cheap , but the 100Mhz model which I have seems to be pretty rare.
the other issue is that unlike the BX6 , this board uses jumpers to control the speed and FSB of the CPU , and since the manual obviously doesn't have the combination for 800Mhz, Im trying to find it somewhere else, according to Gigabyte's website its supported (via a bios upgrade, which Ive already done) , but no jumper settings are given.

on a seperate note I forgot to ask.

since this PC has a GPU based on the Rage Pro card, I figured I might try the ATI version of Tomb Raider, however Im getting an error which states "failed to start ATI CIF" , is this a driver issue? any solution to the problem (I think I just used the driver still on AMD's website)

Rage Pro is much slower on Windows 2000 than on Windows 9x. I once found a great site describing this in detail, but I can't find it at the moment.
The CPU deserves a faster video card anyway. With something like a TNT or TNT2 there shouldn't be much of a difference between the OSes.
I'd probably put the Rage Pro in another box that will be running 9x. Rage Pro is nothing special anyway, common as dirt. If you don't plan to use ATI CIF I'd use at least a Rage 128.

For Tomb Raider have a look at Gona's page.
You have to use one of the working driver versions and Windows 9x.