Effective way to limit RAM to 2 Gb in Win98

[sk9392]

I'm running Win98 on a machine with RLeow's patchmem installed. With a 2 Gb RAM stick installed in the motherboard, there are no issues and performance is decent with games like Half-Life 2 and Far Cry. But I want to dual boot it with other OS like Win7. When I put another 2 Gb RAM stick in the motherboard, the FPS performance of these games falls off by 25% in Win98, which is huge. I've heard that even patched Win98 has a hard time with > 2 Gb RAM.

I've also tried going to msconfig -> Advanced -> Limit RAM - as far as I can see, this has the effect of introducing a MaxPhysPage line in system.ini. Even if I limit to 2 Gb via this method (and even the My Computer properties show 2 Gb of RAM), the same 25% performance drop is still there, which is surprising.

Is there an effective way of software-limiting RAM so that it's equivalent to only using 2 Gb in bare metal?

[user57]

have you tryed with XP ? it is said to not have this problem, but im not certain either

[LoneCrusader]

LIMITMEM

[SweetLow]

13 hours ago, sk9392 said:

I've also tried going to msconfig -> Advanced -> Limit RAM - as far as I can see, this has the effect of introducing a MaxPhysPage line in system.ini. Even if I limit to 2 Gb via this method (and even the My Computer properties show 2 Gb of RAM), the same 25% performance drop is still there, which is surprising.

And why do you think that you got exactly memory size problem in Windows after that? This can be really some other problem like wrong MSRs programming by BIOS with large RAM size.

[sk9392]

1 hour ago, SweetLow said:

And why do you think that you got exactly memory size problem in Windows after that? This can be really some other problem like wrong MSRs programming by BIOS with large RAM size.

You're right, that's certainly possible. I have 2 Gb RAM stick of one type and another 2 Gb RAM stick of a different brand. Maybe it could also be the fact that identical RAM sticks aren't being used? I'll maybe try with a single 4 Gb stick of RAM and see if that works

[sk9392]

18 hours ago, LoneCrusader said:

LIMITMEM

Thanks for suggesting this! Sadly this also leads to that same FPS drop, equivalent to when I put MaxPhysPage=70000

8 hours ago, SweetLow said:

And why do you think that you got exactly memory size problem in Windows after that? This can be really some other problem like wrong MSRs programming by BIOS with large RAM size.

Is it by chance possible to adjust any BIOS settings so that it's equivalent to using 2 Gb RAM, even though I may have more than 2 Gb installed? For your reference, the motherboard I'm using is GA-EX58-UD4. The advanced DRAM settings for it are mentioned on pg 43 onwards here: https://theretroweb.com/motherboard/manual/motherboard-manual-ga-ex58-ud4-e-626fcf8954e64612693978.pdf. If it's okay with you and if you get time, could you check it out once? Maybe there's some BIOS setting that can help with limited RAM detection? Asking because no matter what approach I use - LIMITMEM, MaxPhysPage, etc. - it always leads to degraded performance

 

Also, it seems you're mentioned on this page: https://forum.ru-board.com/topic.cgi?forum=62&active=15&topic=14740&start=1220#19

Quote

The third method is to limit the amount of memory reported to Windows by the HIMEM.SYS driver. It can be called the most reliable, since it allows you to "hide" excess memory from Windows, as if you removed extra strips from the system unit and, accordingly, eliminate all possible conflicts and glitches. Actually, the HIMEM.SYS driver itself cannot be modified, or no one has done it yet, so alternative drivers with similar functionality are used instead. I know Win9x Memory Burn Driver aka BURNMEM  [?] by SweetLow (it differs from the others in that it performs the necessary tweaks at the BIOS level, even before loading HIMEM.SYS), XMGR Special Build 512 Mb Limit aka LIMEM  [?] by MERCURY127 (there is already a new version ) and HimemX by Japheth (with IO.SYS Patch for SafeMode by xrayer ). They allow you to set any memory size, which can help when working with memory greater than 1 GB. This method is also recommended for use during the initial installation of Windows (see point 3 in the next post).

Do you think Burnmem can help in my case?

Edited June 4 by sk9392

[SweetLow]

18 hours ago, sk9392 said:

Is it by chance possible to adjust any BIOS settings so that it's equivalent to using 2 Gb RAM, even though I may have more than 2 Gb installed?

Check this problem (use translator) and solution:

https://forum.ru-board.com/topic.cgi?forum=62&topic=31453&start=100#9

https://forum.ru-board.com/topic.cgi?forum=62&topic=31453&start=120#16

And pay attention to my tool to set/dump MSR/MTTRs state (MTRR_VAR.EXE particulary):

https://github.com/LordOfMice/Tools/blob/master/msr.zip

to compare the state of MTRRs with 2G and 4G RAM.

18 hours ago, sk9392 said:

Do you think Burnmem can help in my case?

As you described your problem - no. As I said I suppose now that this is not the problem in DOS or Windows but it can be fixed.

Edited June 5 by SweetLow

[MERCURY127]

here is latest LIMEM version...
https://www.vogons.org/viewtopic.php?p=1170414#p1170414

[sk9392]

On 6/5/2025 at 2:59 PM, SweetLow said:

Check this problem (use translator) and solution:

https://forum.ru-board.com/topic.cgi?forum=62&topic=31453&start=100#9

https://forum.ru-board.com/topic.cgi?forum=62&topic=31453&start=120#16

And pay attention to my tool to set/dump MSR/MTTRs state (MTRR_VAR.EXE particulary):

https://github.com/LordOfMice/Tools/blob/master/msr.zip

to compare the state of MTRRs with 2G and 4G RAM.

As you described your problem - no. As I said I suppose now that this is not the problem in DOS or Windows but it can be fixed.

Unfortunately, none of these solutions helped. I think it may be a quirk with my particular hardware setup (X58 chipset more specifically)

On 7/4/2025 at 9:47 PM, MERCURY127 said:

here is latest LIMEM version...
https://www.vogons.org/viewtopic.php?p=1170414#p1170414

Thanks a lot mercury. This didn't resolve the issue (maybe some issue with Intel X58 or Gigabyte board that I have (EX58-UD4))

[ABCDEFG]

The EX58-UD4 supports triple channel memory. So it depends on where you put the second stick of memory and also depends on the speed of that second stick, if the second stick is slower than the first the BIOS will automatically set the memory speed to the speed of the slowest stick.

[sk9392]

1 hour ago, ABCDEFG said:

The EX58-UD4 supports triple channel memory. So it depends on where you put the second stick of memory and also depends on the speed of that second stick, if the second stick is slower than the first the BIOS will automatically set the memory speed to the speed of the slowest stick.

True, but even with just a single 4 gb 1333 MHz stick, the same slowdown behavior happens. Win98 works in strange ways from what I've seen - components that work perfectly in other setups, may suddenly start giving problems when used together. e.g. this RAM related slowdown doesn't happen if I use the same RAM, GPU, etc. in a G41MT-ES2L board

[ABCDEFG]

You didn't mention the speed of your 2GB module, nor did you mention latency. And i think you're forgetting that Windows NT uses all the cores your processor has, and Windows 98 can't. So whatever you've tested, of course it will be faster on Windows NT. It has nothing to do with memory size at all. I have 16GB, quad channel on my x79 board and there are no slowdowns because of it, in fact there is an acceleration because all four channels are filled with memory, so the communication between the processor and memory is significantly faster... When I was putting that system together i saw big improvements - a huge increase in fps in the Quake III benchmark, there is a huge difference between single channel and quad channel configuration.

Edited 1 hour ago by ABCDEFG