What version of the game are you using? Have you tried to update the game with official (or unofficial) patches?
https://www.patches-scrolls.de/patch/1361/7/

My bad, the game is updated to 1.51. I've read somewhere that a later (unofficial ?) patch addresses the slow menu performance. Was the menu always slow before this patch?

The menu has very heavy alpha effects, which can kill performance even on much faster cards.

i'd think the menu is more choking the voodoo2 on buffer writes than anything else it's doing for 3d (and this would be worse for SLI - V2 memory is slow and the extra card means double penalty). IIRC a fresh DK2 install would prepare the config for a simpler menu without transitions

leileilol wrote on 2023-12-18, 02:47:

i'd think the menu is more choking the voodoo2 on buffer writes

That's what I was thinking, because the slowdown only occurs when the menus are drawn, not when the menu is transitioning.

leileilol wrote on 2023-12-18, 02:47:

a fresh DK2 install would prepare the config for a simpler menu without transitions

I'm a bit confused about this part, is this just to clear any changes I have made from default? Was there a setting for the simple menu in the installer?

Also, I'm a bit worried that my Voodoo 2 is having issues with buffer writes, because there are some weird horizontal artifacts around the 2d elements of the main menu.

TheMLGladiator wrote on 2023-12-19, 01:13:

there are some weird horizontal artifacts around the 2d elements of the main menu.

If they're purple artifacts that are 4 pixels wide and such, that's normal. This is the video filter feature

Got the game to use my primary adapter (Geforce2 MX) by removing the V2 drivers and reinstalling the game. The menu slowdown persists, so I'm going to assume this holds true for vanilla 1.51 regardless of which card is used.

leileilol wrote on 2023-12-19, 01:40:

If they're purple artifacts that are 4 pixels wide and such, that's normal. This is the video filter feature

It's more like the glitch in the video I linked in my original post, but not as extreme. I'll update my post with a video soon.

Updated original post

The old EA DK2 support page may be useful.

If you click the link for the FAQ page, you will find (among other things):

How do I force DK2 to use a different video card?
You can force DK2 to use a different video mode using the command line switch -DDD <value>
The number that replaces <value> selects the direct draw device. If you have 2 3D cards then you will have three direct draw devices - Software Mode, 3D card #1, 3D card #2. Depending on how Windows has configured these cards, you can select them by using -DDD 0, -DDD 1, -DDD 2 or -DDD 3.

So you don't have to go to such extreme lengths to switch video cards in your testing.

The link for the Troubleshooting page may also be of interest. The DK2 devs seem to have believed that the vast majority of issues in the game were due to driver issues, although there is some indication that particular hardware was to blame in a small number of cases (particular motherboards, etc.). There are some instructions for using the command line switches toward the bottom of this page.

Thanks! I did not know about those command line switches