Edit 09/11/23: Added resolution for the Memory bandwidth issue.
Edit 03/22/24: Added resolution for the 3DMark results issue.
Edit 03/22/24: Formatting.

Hi, thanks for sharing. I like it in general especially the layout and I have a comment and a question.
In OP you mention

using setup /pi to disable ACPI

but it really is:

1setup /p i

And the question is how do you find “modern” activities such as web browsing and IDE/whatever tools you use in Linux in 4:3 aspect? 1200 height is not a huge number by today standards.

mln wrote on 2023-11-08, 16:14:

Unknown Devices in Device Manager

Try the unofficial ICH9/10 drivers from here. I'm not sure if they support X58, but they worked great for my P35 chipset.

I am getting ~10GB/s Memory Read Throughput under both 98SE (AIDA64) and Linux (Passmark) while it should be more like ~20GB/s.
Looks like for some reason memory works in single-channel mode instead of triple-channel. It passes memtest86+ thought.

I've noticed a performance penalty under Win98 if more than 2 GB RAM was installed on my P35 chipset. Try lowering the RAM amount to that and see if it helps.

Thanks for answers, glad you liked it.

Bruno128 wrote on 2023-11-08, 16:28:

Hi, thanks for sharing. I like it in general especially the layout and I have a comment and a question. In OP you mention […]
Show full quote

Hi, thanks for sharing. I like it in general especially the layout and I have a comment and a question.
In OP you mention

using setup /pi to disable ACPI

but it really is:

Copy code to clipboard

1setup /p i

At first I tried with setup only and got exclamination marks for some ACPI devices. With the /pi switch there are no ACPI devices in the Device Manager at all, so maybe it works too.

Bruno128 wrote on 2023-11-08, 16:28:

And the question is how do you find “modern” activities such as web browsing and IDE/whatever tools you use in Linux in 4:3 aspect? 1200 height is not a huge number by today standards.

Web browsing in 4:3 works fine for me, didn't have any issues so far.
Regarding IDE and other tools, I am using Linux with i3 tiling window manager. It has virtual screens and allows to organize them in many ways. It's an efficient and convenient tool after getting used to it. Anyway, these are just hobby activities.

Joseph_Joestar wrote on 2023-11-08, 16:49:

mln wrote on 2023-11-08, 16:14:

Unknown Devices in Device Manager

Try the unofficial ICH9/10 drivers from here. I'm not sure if they support X58, but they worked great for my P35 chipset.

I used them with my previous P35 build and they worked too. I tried them again with this build but Device Manager didn't want to use them.
Anyway, those "drivers" are just an .inf file, so I guess their only purpose is to hide Unknown Devices from Device Manager. I will take a look at them later and try to add X58/ICH10.

Joseph_Joestar wrote on 2023-11-08, 16:49:

I am getting ~10GB/s Memory Read Throughput under both 98SE (AIDA64) and Linux (Passmark) while it should be more like ~20GB/s.
Looks like for some reason memory works in single-channel mode instead of triple-channel. It passes memtest86+ thought.

I've noticed a performance penalty under Win98 if more than 2 GB RAM was installed on my P35 chipset. Try lowering the RAM amount to that and see if it helps.

It seems to also affect Linux benchmarks, so I guess it's more like a compatibility issue between Motherboard and RAM modules. Officially, 4GB are the biggest sticks supported by this board and I have 6 x 8GB.
I don't have any DDR3 modules smaller than 8GB.

After disabling HT in BIOS, 3DMarks look better, but still behind E8600 + X550:

• 3dMark99 (vs. 14079, CPU: 73062 with HT enabled)

  

• 3dMark00 (vs. 12579 with HT enabled)

  

• 3dMark01 (vs. 11480 with HT enabled)

  

1) Disable all but one core in BIOS (along with HT)
2) AIDA64 bandwidth benchmarks scales with core count.
3) Recently ran 48GB of RAM on Core i7 975 on Rampage III Extreme, here's valid : https://valid.x86.fr/vdev1v
Performance is quite good.
4) Never bother with "unknown device" things on X58 under Win98. I would try doing ACPI install again though (just to check performance from it).
5) CPU Configuration I used (don't look at CPU multiplier, I'm on OC'ed 980X) :

agent_x007 wrote on 2023-11-09, 20:14:

1) Disable all but one core in BIOS (along with HT) 2) AIDA64 bandwidth benchmarks scales with core count. 3) Recently ran 48GB […]
Show full quote

1) Disable all but one core in BIOS (along with HT)
2) AIDA64 bandwidth benchmarks scales with core count.
3) Recently ran 48GB of RAM on Core i7 975 on Rampage III Extreme, here's valid : https://valid.x86.fr/vdev1v
Performance is quite good.
4) Never bother with "unknown device" things on X58 under Win98. I would try doing ACPI install again though (just to check performance from it).
5) CPU Configuration I used (don't look at CPU multiplier, I'm on OC'ed 980X) :
CPU Configuration.png

Thank you for the tips. So far disabling HT gave the biggest boost.

I've just tried Tom2D benchmark:

All tests are more or less okay, but the last one (Stretching) is awfully low, thus probably it makes overall score low as well.

Hi

I considered building this type of system some time ago but i was thinking about virtualization + PCI passthrough.

Have you tested / considered this solution?

acl wrote on 2023-11-13, 07:18:

Hi

I considered building this type of system some time ago but i was thinking about virtualization + PCI passthrough.

Have you tested / considered this solution?

Hi, I haven't tested VT-d yet. I have considered this, but since Win98 more-or-less works on the current config, I didn't bother with it.
I guess it's way easier to get Win98 working natively on this build. For VT-d, I would need a secondary graphics card, need to setup qemu and so on.

Did anyone play with custom resolutions in Win98?

I changed my monitor to a 1440p display with digital inputs only. In Linux I am able to get 1920x1440@50Hz using a custom modeline - this is the highest resolution I could get from the single-link DVI present on Radeon X550.
Under Win98 I tried "WinModelines" but no luck so far.

mln wrote on 2023-11-08, 17:41:

Thanks for answers, glad you liked it. […]
Show full quote

Thanks for answers, glad you liked it.

Bruno128 wrote on 2023-11-08, 16:28:

Hi, thanks for sharing. I like it in general especially the layout and I have a comment and a question. In OP you mention […]
Show full quote

Hi, thanks for sharing. I like it in general especially the layout and I have a comment and a question.
In OP you mention

using setup /pi to disable ACPI

but it really is:

Copy code to clipboard

1setup /p i

At first I tried with setup only and got exclamination marks for some ACPI devices. With the /pi switch there are no ACPI devices in the Device Manager at all, so maybe it works too.

Bruno128 wrote on 2023-11-08, 16:28:

And the question is how do you find “modern” activities such as web browsing and IDE/whatever tools you use in Linux in 4:3 aspect? 1200 height is not a huge number by today standards.

Web browsing in 4:3 works fine for me, didn't have any issues so far.
Regarding IDE and other tools, I am using Linux with i3 tiling window manager. It has virtual screens and allows to organize them in many ways. It's an efficient and convenient tool after getting used to it. Anyway, these are just hobby activities.

My main driver machine has a 1920x1200 screen (an old Dell U2410) and I honestly have never had a problem with it. It's plenty of screen space, and like the OP said, the standard multi-desktop and tiling features of most modern Linux desktops environments can make up for a lot; browser/email/Teams is usually on 1, IDE and terminals on 2, VM output on 3, and so on.

Not sure I could cope with a 4:3 ratio any more though! ...

Birthday present to myself this year was a 2560x1440 27" which *just* fits in the shelf space on my desk where the present 24" lives. Well, it will if Amazon ever decide to honour their black Friday prices and send it out.

Finally I got optimal GPU performance under Windows 98 with more than 2GB of RAM installed.
Tl;dr MTRRs need to be adjusted for more than one range.

During my research I found that GPU performance issues with more than 2GB of system RAM are not limited to Windows 98, they affect other OSes as well. For example:
https://bugzilla.kernel.org/show_bug.cgi?id=13042
https://bugs.launchpad.net/ubuntu/+source/lin … .24/+bug/224404

It looks like some BIOS issue rather than OS, since it's BIOS job to correctly set MTRRs.

I blindly tried to fix MTRRs using MTRRLFBE with default arguments, but the issue was still here, so I kept digging.

Next, I tried to understand how MTRRs work. I found that some memory areas need to be marked as WC (Write-Combine) and they should not be overshadowed by other MTRRs, since less caching has more priority.

To see how MTRRs look in my case I used SetMtrr:

There are two memory areas marked as WC:

• 0x8000000-0xBFFFFFF (64 MB area, 3rd MTRR)
• 0xF0000000-0xF7FFFFFF (128 MB area, 10th MTRR)

Both areas are overshadowed by 1st MTRR, which is WB. This makes 3rd and 10th MTRRs not effective.

I tried to use MTRRLFBE again, this time forcing specific memory areas as WC. I created MTRRLFBE.BAT file like following and added it to Autostart:

1C:\WINDOWS\MTRRLFBE.EXE VGA WC
2C:\WINDOWS\MTRRLFBE.EXE USER:0x8000000:65536 WC
3C:\WINDOWS\MTRRLFBE.EXE USER:0xF0000000:131072 WC                                            

It did the trick! I briefly checked some benchmarks and observed better results.

This is how MTRRs look like before and after the fix:

1st MTRR was resized to cover first 64MB and became redundant, since 6th MTRR covers the same area.
MTRRs 6th-9th cover first 1GB and WC MTRRs are not overshadowed anymore. I limit Win98 RAM to 512MB, so I hope this will not cause any issues.

Below are some benchmark results, before and after:

3DMark99 score is almost 2x better. Bandwidth tests in Future Reality also got a huge boost.
I am very satisfied with the results 😀.

Does this impact PCI-E as well, or only AGP devices?

@CursedSilicon
I believe it can affect both, as long as there is more than 4GB of RAM installed.

Interesting. I'll need to take a look at that. I have 16GB (4x4GB DDR2-800's) in my 98 machine presently (mostly for laughs)