Just for experiment's sake I built 4 "all in one" retro PCs a while ago. I'll post the configuration and performance/stability results below:
First PC - budget slow-down computer:
- AMD K6-II 400 ACZ running at 6x66MHz (set multiplier to 2x, the K6-2 interprets it as 6x)
- Lucky Star VIA VP3 AT motherboard
- Voodoo 3 3000 PCI
- Guillemot Maxi Gamer 64
Speed can be controlled in two ways: via a hardware switch fitted to the back of the case - it changes the multipler from 2x(6x) to 2.5x resulting in 166MHz clock speed witch requires rebooting or using SetMuL. It can go down to 386DX-33 levels. Newer games are challenging. Unreal Tournament for example will run and is playable but only offers a pleasant experinece at 640x480 / 16bit colours. Even then, it's not 60FPS. Quake 3 is again, quite playable, but at lower settings. D3D games like Homeworld will run very well until you get lots of ships and projectiles on screen - then it becomes a slideshow regardless of what graphics settings you use. All in all not bad for a cheap socket 7 PC.
Second PC - Super 7
- Aopen AX59 PRO (VIA MVP3)
- Voodoo 3 3000 AGP
- Ensoniq Audio PCI (used to have a AWE64 value in it but I noticed newer games perform noticeably better with the ES1371)
Slowing down is performed exclusively with SetMul, and just like the machine above it can emulate a 40MHz 386DX. Windows games like Unreal and Quake III perform noticeably better, mainly due to 100MHz fsb and 256kb of on-die L2 cache. Using a newer PCI sound card seems to have eliminated some of the occasional stutter I experienced in some windows games, at the expense of real OPL3 (who needs it on this PC anyway, the soft wavetable synth is pretty decent). It's still not a speed daemon, but games like red alert 2 are noticeably smoother on the K6-3/MVP3 platform then on a regular K6-2 and a slower 66MHz socket 7 board. Unreal Tournament runs great at 800x600, same for Quake III. Homeworld however is still choppy with lots of on screen action.
Third PC - VIA C3
- Via C3 Ezra 933MHz
- Shuttle VIA Apollo PRO 133 mATX (can't remember exact model name)
- Voodoo 3 2000 AGP
- Aztec Waverider 32
Good performance in windows games but not on par with a Pentium III of the same speed. Later 2D and RTS games like Red Alert 2 run exceptionally well, but unreal and quake III perform about the same - if not a bit slower then the K6-III. This is due to the C3's slow floating point unit - simply switching to a 933MHz pentium III on the same exact configuration doubles the framerate in any openGL or direct3D game. It can be slowed down using setmul to about the level of a 386-33, and even overclocked a little bit (seems to be stable enough at 7.5x - 1000MHz). I'd say subjectively the performance is very close to the K6-III PC, but at one quarter the price (K6-2+/K6-III prices seem to have exploded lately).
Fourth PC - the experiment
- AMD Geode NX 1750 (socket A) 10.5x133 = 1400MHz
- Abit AN7 (nforce 2)
- Geforce FX5900 (MSI)
- Voodoo 2 12MB (powercolor evilking 2)
- Creative Sound Blaster Live!
Setmul lets you play with the multiplier as well as cache. Lowest multiplier setting is 4x, witch gives a speed of 533MHz. Further downclocking can be achieved via BIOS. In fact the Abit AN7 provides FSB, Multiplier and voltage control via BIOS, as well as cache control. Lowest I could get the Geode is 4x100. Disabling both cache levels yields performance equal to a 50MHZ 486 - according to speedsys at least. This machine does not have an ISA slot, and none of the socket A boards with ISA I own will post with this CPU apart from an Abit KT7, but for some reason setmul freezes on this combination of CPU and motherboard, and the KT7 has doesn't support multipier control via bios. I don't have to describe windows performance on this thing - everything runs smooth even at 1600x1200. As an added bonus, the Geode is a great overclocker. It can go up to 2000MHz with minimal voltage bumps. At 533MHz tough, even with cache enabled, games that would terminate with "Runtime 200" seem to work fine (jazz jackrabbit for example). So far this build covers the widest range of games, being able to run 1991 to 2003 dos and windows games with minimal fuss. The only downside is the lack of an ISA slot and as such real opl3. The only improvement would be finding a socket A mainboard with DDR and an ISA slot - no easy feat.