SetMul can toggle the L2 cache on a Pentium 2. It can toggle the L1 too, but L2 will become non-functional too, as you already found. I did not find an exclusive L1 toggle in the Pentium 2 datasheet.

Am afraid you won't get proper 486 speed out of a Pentium 2. It will be 386-ish.

The program "Throttle" may get you 486 like benchmarking results, but it won't work smooth on every game.

I recommend using MoSlo instead of messing about with caches. It works great for cpu's up to around 500mhz. I tend to use the percentage switch (there's several different slowdown methods) and adjust it per game. Then once I find the ideal setting, I just create a batch file so I don't have to type everything in everytime I play that particular game.

Thanks guys! I'm going to try SetMul to disable the L2 and see if that works and if not then I'll try MoSlo.

There are only a few games I want to try that are speed dependent and I have a K6 based system that slows down a lot easier, I'm just doing this with the P2 to see if it's possible and what it can do.

Talking about L1 and L2 cache can sometimes hide what's happening.

Let's call it CPU cache and motherboard cache.

The problem you are seeing is exactly why I didn't end up using Slot 1 systems for Time Machine projects and went with Socket 7 / Super Socket 7.

Your motherboard does not have motherboard cache. So there is nothing you can do. You can only turn on and off CPU cache, switching between fast as heck and slow as a dog.

On a Super Socket 7 machine the boards have motherboard cache which can be turned on and off separately giving you an in-between performance level usually equivalent to something between a 486DX and 486DX2.

For a fast 486DX2 go with a Pentium MMX or Cyrix. Standard Pentium will end up a bit slower, AMD K6-2 the slowest.

On a VIA C3 it is actually possible to disable L1 while keeping L2 enabled: It is still in the 386 / slow 486 region.
Therefor I suppose there is something about the Pentium Pro/2/C3 architecture that just relies more heavily on L1 cache, compared to socket 7. But I cannot test this theory directly with a Pentium 2 because one cannot run it with just L2.

In addition VIA C3 has a function to disable just half of its L1. On a Nehemiah core this results in 486DX-40-like speed.

Very interesting!

SetMul worked for disabling the L2 on the P2 without shutting off L1, speedsys ID'd it as a celeron 233 and the cache chart showed it. When trying setmul L1D L2E it looked like it worked based on the output it gave but speedsys showed all cache turned off. Tried various combinations but Phil is right, best to go with a Socket 7 setup for this type of work.

I'm done for now playing with this board. It has ended up a dual boot DOS and 98SE. The onboard Yahama sounds really good, better than some of the SB clone ISA cards I have.

The early (dA0-Series) PII-333 can be clocked from 133 to 333. I cleocked mine to 233.
This CPU is much cooler on 233 Mhz as the original PII-233.
Some speed sensitive games do not produce a runtime-error if the cpu is downclocked to 233.
But as you already mentioned the PII-233 is still much to fast for 386/486 stuff.

I did not have checked disabling the cpu-cache or tried moslo or other tools yet,
but i certainly will. I still have a real 486/2-66 but this machine is also way to fast
for some early doesgames like wincommander 1+2.

Maybe if you get a DB0 PII-333 that can handle 500 MHz you could try to run those 386/486 games with both caches disabled ? Your CPU would have a range from 133MHz up to 500MHz with caches enabled or not so I guess that this could be quite nice

No, max is the factory default clock-speed. which means multi @66FSB.
The K6-III+ is more flixible, because it can be run with 66 or 100FSB.

https://en.wikipedia.org/wiki/List_of_Intel_P … microprocessors

Pentium II 266
- SL2K9 (dA0)
- SL2QE (dA0)
133-266 Mhz possible (2x-4x@66FSB)

Pentium II 333
SL2KA (dA0)
SL2QF (dA0)
133-333 Mhz possible (2x-5x@66FSB)

Yeah but with a BX chipset motherboard you can put the FSB up to 100MHz via software

Pentium II 333:
2x-5x*66
But if your CPU handles it, it will be able to do also :
2x-5x*100

No unlocked P2 will handle FSB100.

dr.zeissler wrote:

No unlocked P2 will handle FSB100.

I had more then one unlocked Pii over 100fsb
Go over to hwbot. alot of Pii well over 100fsb

http://hwbot.org/submission/2523584_kotori_cp … 0mhz_725.43_mhz
http://hwbot.org/submission/2137660_veld_cpu_ … 6mhz_451.14_mhz
hwbot.org/submission/2262812_veld_cpu_f ... 619.46_mhz
http://hwbot.org/submission/2782415_strunkenb … y_6be_133.7_mhz
http://hwbot.org/submission/2356474_trekky_re … 6_ii_145.02_mhz
http://hwbot.org/submission/2137661_veld_cpu_ … 0mhz_459.13_mhz

Pentium II 333 SL2QF can do 4.0x100=400MHz, at least if it comes with 5.0ns L2 cache. Otherwise 3.0x100 will work. Pentium MMX can also do 2.0x100=200MHz.
The CPU clock limit relates to total speed regardless of FSB. The motherboard and RAM are the ones taking the stress from running a higher FSB.