Ok tried the DVD s I burnt (memtest, UBCD, Free Dos) but doesn't like it. I take it these machines have issues with DVDs.

Burnt memtest on CD and it worked right away. Found tons of errors, so I binned that stick of ram. Put another one in and all is good.

Burnt the bios stuff on a CD and will try to boot via FreeDOS (which I will also burn onto a CD) and flash the bios and do a benchmark.

Current CPU is a S370 Celeron 500...

Flashed the bios and the Celeron was suddently a 900 MHz model. Intel cpu utility from UBCD confirmed that...

Ran a Norton SI 8.0 with Cache disabled and got 15.6 which turns the machine into a 386SX 20 MHz. Not bad for a start!

Tried a few games and they worked fine...

So disabling L1 cache has a massive performance impact. So one actually needs to find a rather fast CPU to begin with to emulate a faster 386 model?

I got some more cpus here, but I will wait until I get the S370 coolers which have a lever (much easier to mount onto these fragile chips...).

Well the fastest one is a 1.4 GHz PIII so I will hunt one down and see where this gets me.

Enabling L2 cache while L1 was enabled didn't do anything really. Got the same score...

Mau1wurf1977 wrote:

Well the fastest one is a 1.4 GHz PIII so I will hunt one down and see where this gets me.

Just to add to this, there are also Tualatin Celerons (commonly known as Tualerons 😉 )with 256kb cache and 100Mhz fsb. Many of the later steppings can be overclocked by setting the bus speed from 100 to 133 for speeds up to 1.7/1.8Ghz 😉
When going this route, be sure to use one of the later steppings as you'll have more success pulling such an overclock off.

Mau1wurf1977 wrote:

So one actually needs to find a rather fast CPU to begin with to emulate a faster 386 model?

Yep, thats what it boils down to. Slot1 ist the only option to almost come full circle: With 1000 MHz without cache, you reach a fast 386. Try playing with your ram timings too, for fine tuning the speed.
With 133 MHz and no second level cache, you pick it up again at the upper Pentium level. So a slot1 board will offer all speeds but a decent 486.

Thats why I choose it above an Athlon 1400. It runs cooler too.

Edit: An Athlon 1400 can reach 486 speeds, but instead leaves a Pentium gap, since at best it kicks in at 300 - 500 MHz.

So basically, you can't get it all.

Yep, thats what it boils down to. Slot1 ist the only option to almost come full circle: With 1000 MHz without cache, you reach a fast 386.

Ok now I am interested!

Slot1 or socket 370 shouldn't really matter? Or does it?

My PIII @ 1 GHz only nets me a slow 386SX 20 MHz. If I could get a fast 386 I would have completed my projects goal already 😁

Do Slot1 boards / chipsets behave differently?

EDIT: Just realized I had been using PC100 ram. I have 1 PC133 stick but it gives me errors in memtest, still I ran Norton SI 8.0 and the score improved from 16.7 to 19.4 with my PIII 1 GHz.

So it's now at a level of a 386SX 25 MHz or 386DX 20 MHz!

I should get my Slot 1 board soon then I can see how the BX440 and i815 compare performance wise...

Mau1wurf1977 wrote:

Slot1 or socket 370 shouldn't really matter? Or does it?

It surely matters. The socket 370 cpus are all multiplier locked. I don't remember if there are 370 boards with intel and ISA either. For Slot 1, you can get P2 cpus, where you can adjust the cpu clock from 133 MHz up to 500 MHz in bios. This is nice for critical windows games. In fact, if you settle for an LX board, you may go even slower. I can't be bothered, since I want to be able to reach 1000 MHz too, for cache free emulation of XT to 386sx.

My PIII @ 1 GHz only nets me a slow 386SX 20 MHz. If I could get a fast 386 I would have completed my projects goal already 😁

Try to push your ram timings to the limit or use faster ram. Ram speed matters when cruising without cache!

Do Slot1 boards / chipsets behave differently?

With the right CPU they do!

EDIT: Just realized I had been using PC100 ram. I have 1 PC133 stick but it gives me errors in memtest, still I ran Norton SI 8.0 and the score improved from 16.7 to 19.4 with my PIII 1 GHz.

See. Get a working stick or mobo and push the ram. Timings to the limit. Afaik, you'll get by with settings, where windows would puke on your shoes!

Edit: Is your benachmark available for download anywhere?

Yea thanks for the tip!

I believe I posted this in another thread, but lowering the timings from CL3 to CL2 gave me another slight boost. I got 3 PC133 sticks today and they all worked fine!

I am confident now that once my 1.4 GHz S370 cpu arrives I will have reached the (for my project) perfect 386 speed (386DX 25 MHz) with room to slow it down as needed through the BIOS (FSB and RAM speed).

Yes there are plenty of S370 boards with ISA. You can go even faster with early socket A boards, that is something I will surely look into.

Another option are these industrial boards, though very expensive at several hundred dollars. If the BIOS in those boards allow lowering the multiplier, then using any current Celeron like a E3300 would allow you to do some amazing things.

You could not only lower the CPU speed from 3 GHz down to 800 MHz, you can also lower the Ram speed and therefore have a massive performance scaling from top to bottom.

So yea, lots and lots of options. However S370 is very cheap. Boards are much easier to find and cost less and 386 or 486 hardware. They are ATX so can use new cases and power supplies, they work with current IDE DVD burners, documentation is readily available, no jumpers because you set everything in BIOS or it's set automatically....

Mau1wurf1977 wrote:

Yes there are plenty of S370 boards with ISA.

And Intel chipset? Well anyway, they don't let you emulate a P1.

You can go even faster with early socket A boards, that is something I will surely look into.

I suggested this to you in another thread, but I myself have abandoned that idea for now.
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The current board I am playing with has a VIA chipset! It has 1 ISA slot and the others are all PCI. Onboard graphics which I use (Trident or something)...

Has worked fine so far!