VOGONS


First post, by bertrammatrix

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After sporadically buying a few AMD 5x86 here and there over the last 2 years everytime I could get a decent price in hopes of eventually finding one that can run on a 60/66mhz fsb... I finally found one!

The cpu, an ADW, known to me as "#12" (but actually the 20th-something one I've tested)

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Other System specs:
Pcchips M919 v3.4 motherboard
Pancakepuppy's 1mb L2 cache module @ 2-1-2
128mb 60ns edo ram (Samsung tsop) @ 1/0 ws
Matrox G200 pci 16mb
Promise Ultra TX2 pci IDE
Ymf 719 based sound card

The system is fully windows stable at 180mhz with the CPU voltage at 3.7 volts and a large heatsink with a fan lightly blowing over it. 200mhz is possible at the same voltage with increased airflow, and I was able to play Worms Armageddon for a few hours without any issues, HOWEVER - during shut down the system would hang, no matter what I did. Not wanting windows registry issues I'll stick to 180mhz for "regular use" for reliability's sake (as reliable as a m919 running at these speeds gets anyway)

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Reply 1 of 12, by bertrammatrix

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Some more numbers:

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Performance at 180mhz. Note, the FPU speed here is actually slightly lower then what my Cyrix at 2x60mhz scores in the same motherboard with enhancements enabled, however I have yet to find a game in which the AMD at 180 wouldn't feel faster. Obviously this is a bit of an apples to oranges comparison though as the cyrix needs much relaxed cache timings compared to the AMD.

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Reply 2 of 12, by pshipkov

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Well, your 200mhz configuration is impressive. Best quake 1 score with 486 cpu so far.
Tell us more about it - bios version, ram chips (looks like samsung), post few more scores like Doom test.
Did you run any other more challenging benchmarks to verify stability?

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Reply 3 of 12, by red-ray

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Well done, I wonder if my SIV utility correctly reports the CPU speed, please will you try it?

Ideally use SIV V5.82 Beta-05, do Menu->File->Save Local and post the save file.

Below you can see it's OK on my system, but I have never tested it with a 60/66 MHz FSB speed.

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I wonder why CPUZ reports the L1 cache size + technology for your CPU, but not for my CPU when that are basically the same CPU.

At x4 it repots the technology, but still no L1 cache size.

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I wonder if your system would be more stable a 4 x 50 MHz, have you tried it?

Reply 4 of 12, by bertrammatrix

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pshipkov wrote on 2025-07-04, 05:55:

Well, your 200mhz configuration is impressive. Best quake 1 score with 486 cpu so far.
Tell us more about it - bios version, ram chips (looks like samsung), post few more scores like Doom test.
Did you run any other more challenging benchmarks to verify stability?

Thanks. I've been wanting in the club for some time now and working hard at it 😁

Didn't someone score around 25 with a 1:1 fsb/pci ratio? I could probably milk out an extra fps if I used one of my cards that can do that speed, however not that motivated since the G200 outperforms those under windows regardless of the benchmark score.

Bios version is stock for this board 05/06/1996. Extensive testing confirmed findings of others that all the other bioses available have a gap in the cacheable range between 56-64 mb, leading to lower performance, while not giving any other observable benefit. I tried a few award bioses of similar boards as well, but these all had other issues. Note, this bios also works flawlessly on a v1.5 board (that has a version with the memory gap from factory).

The edo ram has 5v tsop Samsung ic's - km44c16104bs-6. I tracked this down after some recomendations from Feipoa regarding Samsung tsop ram. I also have a 64mb 40ns (!!!) module with soj Samsung chips that performs flawlessly, however since there seemed no difference stability wise I obviously stuck with the 128. I also had great results with a 64mb module of Samsung tsop FPM - benchmark results were 1-2 us/mbps better with this and no instability was noted (I think one of my benchmark result photos is with this module). However, the FPM "felt " a tad slower in windows - not sure if EDO is playing a role here, or, if the FPM is at the edge of it's capabilities and I am getting cache misses or something that affects the performance.

Yeah I can post some more results.

So far, close to a week in, all seems stable, even leaving demanding windows games paused with winamp in the background etc all day has not triggered anything. I've messed with a few of these less successfully and usually causing lockups or errors isn't a problem

Reply 5 of 12, by H3nrik V!

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Wonder if you could get by that shutting down issue by clocking down on the fly, just before closing Windows. My 486SOM's clock generator can switch frequency live, clocking up or down as needed. By red-ray's inspiration, I added switches rather than jumpers, to be able to switch as I please ..

The multiplier, though is read at reset, so that's not a live switch ...

If it's dual it's kind of cool ... 😎

--- GA586DX --- P2B-DS --- BP6 ---

Please use the "quote" option if asking questions to what I write - it will really up the chances of me noticing 😀

Reply 6 of 12, by bertrammatrix

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pshipkov wrote on 2025-07-04, 05:55:

Well, your 200mhz configuration is impressive. Best quake 1 score with 486 cpu so far.
Tell us more about it - bios version, ram chips (looks like samsung), post few more scores like Doom test.
Did you run any other more challenging benchmarks to verify stability?

Here is a few more benches

Doom

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Pcplayer 320 and 640

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Reply 7 of 12, by Disruptor

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Did you do your test with the G200 or the Virge?

Reply 8 of 12, by The Serpent Rider

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S3 Virge can't work stable at 60 MHz. At least I haven't encounter one that could.

I must be some kind of standard: the anonymous gangbanger of the 21st century.

Reply 9 of 12, by maxtherabbit

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Very impressive results

Reply 10 of 12, by bertrammatrix

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Disruptor wrote on Yesterday, 14:59:

Did you do your test with the G200 or the Virge?

Sharp eye. That round in particular was done with an S3 virge (with a 75mhz clock) and I believe FPM memory. I was wanting the virge in there as the g450 I usually use for dos tests (as it scores identically to my g200 which usually lives in a system/doesn'tserve as a test card) does not have windows 98 drivers that work on a 486.

The virge consistently scores about o.2 quake fps LESS then g200, while using FPM consistently scores about 0.2 more then using edo. SO, virge + FPM or g200 + edo yields an identical quake score. The virge obviously lacks heavily under windows compared to the g200

Reply 11 of 12, by bertrammatrix

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The Serpent Rider wrote on Yesterday, 15:30:

S3 Virge can't work stable at 60 MHz. At least I haven't encounter one that could.

I agree. I tested several and always had problems eventually. The ones with a lower clock rate did a little better but never reliable.

HOWEVER, I'm NOT running this one at 1:1 fsb/pci, so the pci is comfortably running at 30mhz. Honestly, I can't be bothered to hot switch it every boot to achieve a 1:1 pci at this speed (which is the only way to force it on a 919). I've had mixed results with running 60mhz pci on SiS and Ali boards - sometimes there is an extra fps to be had, sometimes not. I remember the Ali board in particular scoring over 100 in 3d bench with a sis6326 and a 2x60mhz cyrix which was very impressive, however the improvement to any other benchmark (or to the feel of games under windows) was very minimal

Reply 12 of 12, by pshipkov

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Yes, thats evident by your Doom framerate. It is around 60, which if far below the 80 if you run at 1:1.
Basically, runtimes that can saturate the pci/vlb busses will suffer significantly.

Thanks for the additional details.
Linked you from a big thread related to this stuff.

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