Hmm I would be surprised if such a tool exists...

Regarding FSB, the best you can hope for are some boards allow changing the FSB in the BIOS.

With CPU and mainboard cache disabled, it doesn't make a difference. 66 or 100 MHz: You have a 386DX.

So on a K6 the slowest you can get is a 386DX. Any slower and you can do things like slow down the RAM timings, use EDO instead of SDRAM. E.g. with EDO Ram you get a 3dbench score of 8, that is on the level of ~ 20MHz 386. The 16MB module in my time machine is such an EDO RAM. I haven't played around with RAM timings, but it seems to have a tiny bit of an impact.

Now if you went with a Pentium MMX, there is no way to get it slow enough. It's the "fastest" cacheless CPU...

With mainboard cache enabled (and CPU cache disabled) the FSB however has a huge impact. The higher, the faster the machine. On a K6 however you won't get much more than a 486DX. The K6 is the slowest "cache less" CPU, which IMO is good!

And for 3D games, just set the multiplier to 6x and you have quite the rocket 😀

Check out this video: http://www.youtube.com/watch?v=2rPhi9-ILHw

It has benchmark results as well.

3dbench database for reference: 3DBENCH CPU Benchmark Database

FSB makes a difference, because it you use the same multiplier it forces your CPU to run at a lower clockspeed. However as i am testing just right now with a K6-2, i get the following results:

With all caches disabled, 83MHZ bus x 2 multiplier:

Score of 9650 Dhrystones on NSSI. This is equivalent to a 386 DX 33.

With all caches disabled, 50MHZ bus x 2 multiplier:

Score of 6570 Dhrystones on NSSI. This is slightly faster than a 386 DX 25.

With the additional slowdown with SoftMPU the system is now equivalent to a 386 DX 25.

I guess i have to give up on Test Drive III. Not too bad, my main focus is Wing Commander.

Loosen the RAM timings, and there are other chipset setting that slow things down.

And you can always purchase EDO ram (they still come in the SDRAM shape).

Also, have you tried Test Drive 3? Does it still run too fast?

I recently made a k6-3+ 400 with an embedded chip running at 2.1 volts. Its an interesting platform but I havent had time to play yet.

Mau1wurf1977 wrote:

Loosen the RAM timings, and there are other chipset setting that slow things down.

And you can always purchase EDO ram (they still come in the SDRAM shape).

Also, have you tried Test Drive 3? Does it still run too fast?

I'm not testing this on the Super Socket 7, as it is not finalized, but on a QDI Titanium IB+ Socket 7 with a patched BIOS to support K6-2's and K6+'s. And yeah i do know about RAM timings/latencies and bloody waitstates, but this will be very inconvenient because it does not serve my purpose of what i wanted to do.

About Test Drive 3, yes it is still not running perfectly, but almost there! So with some waitstates it would get there, but this is totally inconvenient. I would love to do everything with DOS prompt.

I believe a 100MHZ FSB x 2 multiplier will give me a speed equivalent or close to a 386 DX 40, which is still quite a bit for Wing Commander, i guess a bit to fast when nothing is around but playable when fighting the Kilrathi.

I have to check the DFI BIOS, to see if i can do the FSB there, which as far as i remember i can't. I think it's only done via switches on the PCB.

Just a side note, with this caching enabling/disabling thing we do, we can see how outdated and limited the x86 ISA is. I often wonder how computing today would be if IBM had chosen Motorola instead of Intel.