Hi folks,

I am testing a K6-2 system and I've found a curious problem...

Basically the more RAM I install, the worse is the 3D performance.

I've tested from 64 to 512Mb with combinations of various PC133 modules. With 64 the system flyes, but starting with 128 and more the performance decreases. I've done the tests with 3DMark99 and 2000.

I don't understand what's wrong, it should be the opposite. More RAM should give better performance!

Have you got any idea of what's going on? This computer is driving me crazy haha 

mirage111 wrote on 09.01.15 at 23:13:09:


uhmm, just a small correction.....more ram does not equal better performance...it does to a certain degree, but better statement is ram doesn't decrease performance......or at least it shouldn't

What OS are you running? win98? if so, be sure to install the patch for more ram capability, since originally, win98 doesn't like ram above 256MB all that much

Google for win98se unofficial servicepack, it is included in that.

But if it becomes noticable even with only 128MB....then I think something else is wrong.

Can you motherboard model, what kinda ram etc etc?!

Try also the newest bios possible. And see in bios if your memory timings are set to automatic... maybe when you put more ram, the bios sets higher latency for compatibility and thus the memory works a bit slower, so the overall performance is slower.

My board has 512Kb cache and it is activated in BIOS. Thandor, do you mean that more than 128Mb RAM is useless  with this chipset and this amount of cache? However, in that case, adding more RAM shouldn't make the system slow, shouldn't it?

Well, I've installed the service pack and the problem is still there but I have managed to put 128Mb without performance loss, using a single module. I've also tried with a 256Mb single module and the performance falls again, and I am not talking about a little bit loss, it is clearly noticeable.

I've also checked the BIOS as you suggested but I think it is OK. Anyway, here are two pics, so you can tell me if you see something wrong.

mirage111 wrote on 11.01.15 at 14:36:37:
Yes, with more than 128MB RAM it will generally be slower because it won't be cacheable. More than 128MB will only be faster if you really need 256MB or 512MB of RAM. (Uncached RAM is always faster than caching to a traditional hard-drive, but cached RAM is faster than uncached RAM and will do just fine if you 'only' need 128MB RAM).

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As far as I know the unofficial service pack won't allow you to use more than 512MB RAM in Windows '98 SE, it will only make sure that Windows '98 SE shows the correct amount of RAM if you have (too) much RAM installed.
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So you just have to stick with one 128MB RAM module.

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I would say it's pretty much OK. You can try to configure 'SDRAM CAS Latency' to 2.5 (or even 2.0) depending on your RAM module. Often 100MHz modules are CAS2.5. If you run a 133MHz CAS3.0 module on 100MHz you can configure it for CAS2.5 if you run it at 100MHz.

Those are the modules I've tested:



All of them are single sided except the Kingston 256, and all of them are PC133 except the IBM module, wich is PC100 as you can see.

Well, let's go for one thing at a time.

Goriath, the loss seems to be related to the amount of memory installed. I've tried different combos like 128+128, 256+128, 128+128+256, and so on... Everything over 128Mb results in a performance loss. I've also tried different slots in the board, with no difference.
I relation to BIOS updating, the board I'm using has version A7 and the newest I found is version A9. I have also another board of the same model, but older, wich has version A3. I will test the version A3 with more than 128Mb and see what happens. At the time I prefer not to update BIOS because those old parts are getting hard to find for me and, you know, something could go wrong and ruin the board. So I keep update as the last try.

Thandor, I don't need more than 128 really, 'cause I use these computers for gaming the games of that era, you know, Unreal, Quake, etc... And they go fine with 128, but I've never seen a worst performance with more RAM so I'm curious about it, and want to find out if there is a problem or it's just the way it works.
About CAS latency configuration in the BIOS, I've tried 2 and 3 (There is no 2.5 setting in my BIOS) but it's the same.

Ultima, I see the 133 modules have 75 printed in some places, so I think they are 7.5ns modules. Anyway, you can check the picture.

Thank you for your great help guys, I always learn a lot from this forum.