Right, I'm going to get to the bottom of this *raises fist to the sky*
I don't have a 128MB stick, but I just ordered one, and should get that in a few days, then I'm going to strip the system down, to just what you suggested... and see what happens.

Would it help at all, while waiting for that ram, if I posted my bios settings, in case anything stands out to you?

Try adjusting the CAS latency... The lower the better.

Is there a setting for DRAM Timing that is faster than Fast?

Can you disable DRAM integrity mode?

Note.. the first two can lead to instability songs ready to reset the BIOS if it fails to POST.

Only change one at a time.

DRAM Timing options are just Normal or Fast
DRAM Integrity options are just ECC or Parity

Could this be related?
K6-2+/III+ slowdown issues on ALi Aladdin V
Unfortunately I don't see if they ever resolved that...

I can check the bios settings with my P5A for you tonight, where I got the scores from I posted earlier.
I can check the drivers I installed as well.

I ran the memory benchmarks in aida32
The attachments are at 600mhz, but when I set the multiplier to 5.5 the write speed actually went up to 115MBS. Due to this, I ran 3dmark99 at 550mhz, and got 2400/7369, a bit lower than previously, so I'm not sure why that write speed was higher when I slowed I the cpu.

RockstarRunner wrote on 2020-09-30, 10:20:

Could this be related?
K6-2+/III+ slowdown issues on ALi Aladdin V
Unfortunately I don't see if they ever resolved that...

Don't think that would explain the very slow performance in Quake 2 (software mode). Also, you already have "VGA frame buffer" enabled.

Very strange issue, indeed... (but a lot of fun 😀 )
There's nothing that stands out to me as an indication of a potential issue. Your BIOS screens look good, and the Aida memory tests are also OK (even though the write speed is a bit on the low side).
Now you got me curious, I really want to test and debug a board with the Ali chipset (the last time I used a SS7 board with Ali Aladdin V was... 20 years ago).

Hope this helps

I guess the only next step I have is to wait for the ram (doubt it will help, wouldn't explain the big performance drop) then strip it down to the basics and build up, testing as I go. And after that, if it still doesn't change then I've no idea....
Would be interested to try with a non + CPU, but I'm not spending any more money on this.

Try setting GAT mode to 0 in the ALi AGP Tool and see if you get any difference

Garrett W wrote on 2020-09-30, 19:45:

Try setting GAT mode to 0 in the ALi AGP Tool and see if you get any difference

This would not explain the slow performance in software mode.

Decided to run memtest86... Why does it say I don't have any L3 cache?! Shouldn't that be the motherboard cache? Could it be bad/dead and thus explain the slowdown?

Please, anyone with a k6-2+... If you could share your results from memtest86 that would really help.

(I'm using memtest86+ 5.01 floppy version)

I don't think that would explain such a performance hit with a K6-2+ CPU. Typically, when the motherboard cache is disabled, the performance hit with a K6-2/3+ should be less than 10%, usually about 5%.
Anyway, I can check one of my SuperSocket 7 boards in the next days (because I'm currently doing tests with other platforms), and will get back to you.

But, what if the L3 was bad, and I'm using a 256MB ram stick? Still waiting on the 128MB stick to arrive. I tested with the external cache on and off on bios, difference was negligible.

It should be the same. When talking about a K6-2/3+ CPU, I don't expect performance to drop by more than 10%, even if the cacheable RAM size is exceeded and / or motherboard cache is disabled.

I guess the L3 cache is ok, according to this test...
I got the 128mb stick today, so I'll retest it all now

Is there any reason that the info screen in 3dmark 99 would show the bus as PCI?

With 128MB stick, I saw minor improvements, but definitely still something wrong. I've tried many things, but nothing really helps. I'm about to give up.

RockstarRunner wrote on 2020-10-07, 15:04:

With 128MB stick, I saw minor improvements, but definitely still something wrong. I've tried many things, but nothing really helps. I'm about to give up.

See here:
http://www.k6plus.com/phpBB3/viewtopic.php?t=1118

Looks like this board had issues with the K6-2+ even back in the day.

Maybe try the F7B BIOS as well. It is available directly from Gigabyte.

I vaguely remember seeing a video from Phil's computer lab where he ran into the issue of an AGP card showing up as PCI and that limited performance for him as well. I am not sure if it was driver related or chipset