marxveix wrote on 2025-11-02, 12:02:

I am new do this LFB and FastVid. Is it possible to have LFB performance boost to other CPU-s as well? […]
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Dan386DX wrote on 2025-11-02, 00:29:

Used SET6X86 to modify a register with the aim of tweaking LFB performance on my motherboard's onboard GPU (ATI Rage Pro 3D) - a bit like a DIY FastVid because FastVid won't work on this system.

I am new do this LFB and FastVid. Is it possible to have LFB performance boost to other CPU-s as well?

FastVid is for Intel
K6INIT is for AMD
CYRIX has no tool?

What about other less known CPU-s, like Transmeta Crusoe?

Good question, I honestly don't know - I'd have thought in theory it's possible on any x86 processor, although IIRC, Transmeta Crusoe while able to emulate x86 microcode is architecturally wildly different. It's possible a tool exists somewhere but seems unlikely

@feipoa

Well, this is embarassing.

It turns out, my SET6x86 tweak did *not* work.

You know what had triggered the VGA/LFB improvement? I'd switched the FSB/Multi jumpering from 83*1.5 to 100*1.5 and completely and utterly forgotten.

LFB scales with FSB (of course it does).

I'm going to take a little VOGONS break for shame. Thank you all for puting up with me 😁

FastVid is ok with all older configurations/video cards, and FVid gives good results on modern configurations and with today's video cards.
The latter, for example, gives about a 2x FPS increase with Q2DOS, with a relatively small GTX1650 card.

Socket 7 systems are so easy/fun to experiment with! I tried an IBM 6x86MX in mine and it looks like it has 4 options for the multiplier: 2x, 2.5, 3 and 3.5x. I tested at its extremes, and compared it with a K6-2 and K6-3. I timed how long it took to compile bash (in linux):

200MHz (2x100) 59:33
210MHz (3.5x60) 69:35
210MHz (3.5x60) 74:20 K6-2
210MHz (3.5x60) 56:10 K6-3

So it seems to be between the K6-2 and k6-3 in performance. The decent cache means it is not extremely sensitive to the bus speed.

Yeah, Cyrix made a really good processor back in the day.

I really want to get ahold of a joshua one day.

Yeah preliminary testing was showing it to hand celeron it's own ass at same clockspeed, though they still had overoptimistic PR nonsense going on. The centaur replacement seemed like such a disappointment for the first couple of spins, worse. I guess maybe it couldn't develop for low power like that could in later iterations.

Which version of the 6x86 would have a good chance of working at 300MHz? I've been looking on ebay and "333" seems to be the highest rating available now for usa buyers. Is there a better source?

As far as the small selection i have tried over the years goes, 35, 30, 25 micron 233, 266, 333, 366 all seem to be hitting a wall at 290, even with massive coolers on them. Though I've never taken the core volts up from 2.9. So I guess it takes a 2.2V 18 micron to get over that hump comfortably, or a "golden sample" in the silicon lottery.

I was noticing the other day though how expensive everything over 233 is getting. 6x86 in general too, seems odd to me that they seem in general more expensive than most of the Winchips now, when the winchips were thought to be rarer a decade back.