tegrady wrote on 2022-10-23, 04:16:

First off, my system specs: […]
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First off, my system specs:

Windows 98 SE
Asus P3V4X mb
Pentium 3 1000mhz CPU
3dfx Voodoo 3 3000
SB Awe 64 Gold
512mb RAM
I have tried using an SSD with an IDE to SATA adapter, a mechanical SATA HDD with an IDE to SATA adapter and an IDE hard drive. I get the exact same problem with all three storage variations.

The problem:
When I run Duke 3d in a WIndows 98 window, it runs flawlessly.
However, when I run Duke 3d in pure DOS mode, the game stutters every few seconds. It will run smoothly for a second, then it will stutter for a second, and it keeps repeating. The sound stutters at the same time the video stutters.

I'm assuming it's configuration issue somewhere and not a hardware issue as it runs fine in Windows 98.

When I boot into pure DOS mode, I do not get any error messages. It says that the Sound Blaster has configured correctly.

Any idea what is going on here?

If you need me to post more info, please let me know exactly what you want to see.

Thanks.

Are you using any midi devices attached to the AWE64?

tegrady wrote on 2022-10-23, 04:16:

It will run smoothly for a second, then it will stutter for a second, and it keeps repeating. The sound stutters at the same time the video stutters.

Sounds like Smartdrive isn't loaded. While in pure DOS, try running this before starting Duke3D and see if that changes anything:

1C:\WINDOWS\SMARTDRV.EXE

If it helps, you might want to add that line to C:\WINDOWS\DOSSTART.BAT.

Similar here, not that I have your config, but I have P3-866, using Voodoo 3 2ooo and exactly same - in many games I noticed this, that +when. in pure DOS mode, my games stutter, some work fine in Win95 Dos some work fin in Win Dos mode... until now, I have not been able to find whats wrong...

Another hint. Do you have write combine cache mode enabled for the framebuffer while playing in DOS?
I don't know if your card's bios enables it when entering VESA modes in DOS, Windows drivers did that for sure.
I remember UNIVBE did enable write combining for my i740, the frame rate becomes radically better.

So the Duke 3D being software renderer is capped by the video ram bandwidth. It's easy to imagine a scenario when worse memory throughput causes stuttering when the game engine waits for graphics/audio paths synchronized, and graphics being lagging behind. With write combining enabled by the Windows the vram write performance gets much better, graphics won't lag too much to cause stuttering.

AppleSauce wrote on 2022-10-23, 05:35:

tegrady wrote on 2022-10-23, 04:16:

First off, my system specs: […]
Show full quote

First off, my system specs:

Windows 98 SE
Asus P3V4X mb
Pentium 3 1000mhz CPU
3dfx Voodoo 3 3000
SB Awe 64 Gold
512mb RAM
I have tried using an SSD with an IDE to SATA adapter, a mechanical SATA HDD with an IDE to SATA adapter and an IDE hard drive. I get the exact same problem with all three storage variations.

The problem:
When I run Duke 3d in a WIndows 98 window, it runs flawlessly.
However, when I run Duke 3d in pure DOS mode, the game stutters every few seconds. It will run smoothly for a second, then it will stutter for a second, and it keeps repeating. The sound stutters at the same time the video stutters.

I'm assuming it's configuration issue somewhere and not a hardware issue as it runs fine in Windows 98.

When I boot into pure DOS mode, I do not get any error messages. It says that the Sound Blaster has configured correctly.

Any idea what is going on here?

If you need me to post more info, please let me know exactly what you want to see.

Thanks.

Are you using any midi devices attached to the AWE64?

Nope.

vstrakh wrote on 2022-10-23, 08:05:

Another hint. Do you have write combine cache mode enabled for the framebuffer while playing in DOS? I don't know if your card's […]
Show full quote

Another hint. Do you have write combine cache mode enabled for the framebuffer while playing in DOS?
I don't know if your card's bios enables it when entering VESA modes in DOS, Windows drivers did that for sure.
I remember UNIVBE did enable write combining for my i740, the frame rate becomes radically better.

So the Duke 3D being software renderer is capped by the video ram bandwidth. It's easy to imagine a scenario when worse memory throughput causes stuttering when the game engine waits for graphics/audio paths synchronized, and graphics being lagging behind. With write combining enabled by the Windows the vram write performance gets much better, graphics won't lag too much to cause stuttering.

The weird thing in my case is that I was using this same hardware config last year and it worked fine. Somehow my Windows 98 SE install got corrupted, so I had to wipe the hard drive and re-install everything fresh. The problem didn't occur until I reinstalled everything.

I don't know if I have combine cache mode enabled in DOS. I've never had to manually enable anything like this before and I have built dozens of DOS/Windows 98 machines and never had this problem before.

Thanks.

Joseph_Joestar wrote on 2022-10-23, 05:55:

Sounds like Smartdrive isn't loaded. While in pure DOS, try running this before starting Duke3D and see if that changes anything […]
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tegrady wrote on 2022-10-23, 04:16:

It will run smoothly for a second, then it will stutter for a second, and it keeps repeating. The sound stutters at the same time the video stutters.

Sounds like Smartdrive isn't loaded. While in pure DOS, try running this before starting Duke3D and see if that changes anything:

Copy code to clipboard

1C:\WINDOWS\SMARTDRV.EXE

If it helps, you might want to add that line to C:\WINDOWS\DOSSTART.BAT.

I'll try this now. Thanks!

tegrady wrote on 2022-10-23, 13:04:

I don't know if I have combine cache mode enabled in DOS. I've never had to manually enable anything like this before

The Write Combine mode appeared starting with Pentium Pro CPU, it's related to Memory Type Range Registers: https://en.wikipedia.org/wiki/Memory_type_range_register.
This is not something usually configurable in BIOS, and DOS surely could not be aware of it. UNIVBE is one of tools that is aware of this relevant feature and can enable it. The videocard's own BIOS is probably not allowed the luxury of requiring certain CPU family, or introducing possible compatibility issues from changing the memory caching modes, so in pure DOS you normally will not see this feature active.
There are other user-made tools, like this one quickly googled: http://rayer.g6.cz/programm/programe.htm#MTRRLFBE
The author measures boost as "got transfer rate (RAM->VRAM) gain eg. in 800 x 600 / 32 LFB mode from 62 MB/s to 315 MB/s."

Joseph_Joestar wrote on 2022-10-23, 05:55:

Sounds like Smartdrive isn't loaded. While in pure DOS, try running this before starting Duke3D and see if that changes anything […]
Show full quote

tegrady wrote on 2022-10-23, 04:16:

It will run smoothly for a second, then it will stutter for a second, and it keeps repeating. The sound stutters at the same time the video stutters.

Sounds like Smartdrive isn't loaded. While in pure DOS, try running this before starting Duke3D and see if that changes anything:

Copy code to clipboard

1C:\WINDOWS\SMARTDRV.EXE

If it helps, you might want to add that line to C:\WINDOWS\DOSSTART.BAT.

OK, I tried that and it didn't seem to change anything. Oh well. Maybe I'll try another video card to see if that is the issue.

Have you tried it with sound disabled? If working after that then try disabling just MIDI. Also try lowering the sample rate.
You'll likely need to use a different sound card or another card for MIDI.