Very slow 1998 game on modern GPU

I can run a popular 2015 game at 4K on medium settings at such a rate I see video quality (no delay long enough to see there was a delay between frames) unless I get within 5-10% of the most active parts of the game, which are in vast majority mildly slow. I've recently installed a 1998 game from a well-known developer and by default it had high setting and it was--very--slow; not only it was visually unappealing but it had such a low frame-rate I couldn't visually gauge the speed and couldn't stay on the road for all but the smallest curves. I then change the game settings to medium with a quite similar result, then to low settings seemingly just as slow as for high settings. I then used compatibility mode to try Windows 98 mode and the game wouldn't get to the starting menu, nor see the preceding introduction video. I then tried Windows XP SP3 mode, which seemed about as slow as my attempts at regular Windows 10 mode.

Windows 10 version: Pro 22H2 19045.2486

Thank you kindly for your help

Ghot said:

What is the name of the game?

Interstate '76: Nitro Pack

The instructions I've seen require a decent amount time. I found a seemingly quick patch but have some registry modifying files (.reg), it's Interstate ’76: All-in-One Patch for Windows 10 (2020) « REPLAYING.de; is there a way to insure the registry modification are limited to the game before running them?

DynV said:

Interstate '76: Nitro Pack

from the GoG comments section for the game:

Code:

1. Go here and download dgVoodoo. Downloads - Dege's stuffs
2. Unzip and copy all the files to your Interstate 76 (and Interstate 76 Nitro Pack) folder. If it asks you can just skip because Interstate 76 from GOG comes with some of the v1.50 Beta 2 files, but not all of them (okay GOG... Why did you guys strip out the setup util?!  Arrgh!)  Make sure you copy over "dgVoodooSetup.exe".
3. Run "dgVoodooSetup.exe" and select "Direct3D9" in the Render API drop-down list box. If you leave the default at Direct3D7 when you start driving the screen will go black, however the menus will still work.
4. Click on the "Glide" tab.
5. Select the resolution you want to play at in the Resolution drop-down list box.
6. Click OK.
7. Launch Interstate 76 Glide version.

tomdsr said:

from the GoG comments section for the game:

Code:

1. Go here and download dgVoodoo. Downloads - Dege's stuffs
2. Unzip and copy all the files to your Interstate 76 (and Interstate 76 Nitro Pack) folder. If it asks you can just skip because Interstate 76 from GOG comes with some of the v1.50 Beta 2 files, but not all of them (okay GOG... Why did you guys strip out the setup util?!  Arrgh!)  Make sure you copy over "dgVoodooSetup.exe".
3. Run "dgVoodooSetup.exe" and select "Direct3D9" in the Render API drop-down list box. If you leave the default at Direct3D7 when you start driving the screen will go black, however the menus will still work.
4. Click on the "Glide" tab.
5. Select the resolution you want to play at in the Resolution drop-down list box.
6. Click OK.
7. Launch Interstate 76 Glide version.

It's still slow, but > 10X better than it was before doing your suggestion. Do you know how dgVoodoo work and could get better performance? I feel my system could handle the game--considerably--better than this improved version; at the beginning of the OP I mentioned what it can handle.

Thanks again

Ghot said:

You may have to also use this from post #4...

Interstate '76 GAME MOD i76 25FPS Fix - download | gamepressure.com

It may have improved the situation, but if so not significantly.