afaik it's not supported, depends on how old the installer is that you use

Talking about the last official version.

http://www.falconfly.de/directx.htm

Personally I think that's rubbish, I've installed dx9c on all my Win98se machines and haven't encountered any problems.

I guess if You are only wanting to run older titles and have an older machine, and have a video card that is dx8.1 hardware or older
then maybe installing dx9 might reduce performance. I would have thought someone must have benchmarked this by now?

I typically run DirectX 7.0a because after lots of experimentation over the years I've found this version to be the last really stable choice. Anything beyond that and I see more frequent BSODs, especially with subsequent launches of 3D programs during a single session.

I also use 7.

Question: Are there even any DX8 games, that do not run under Windows XP?

Since DX7, each version got its own API and libraries, so the different versions exist alongside eachother.
Installing DX9 should not affect DX8 and lower.

PhilsComputerLab wrote:

I also use 7.

Question: Are there even any DX8 games, that do not run under Windows XP?

The only one I'm aware of is from an unofficial patch: Unreal.
On my Win98 PC I have a DX9 card (FX5200) and with the oldunreal.com patch I can run Unreal in D3D9 with better performance than any other D3D or OpenGL mode in the game.

clueless1 wrote:

PhilsComputerLab wrote:

I also use 7.

Question: Are there even any DX8 games, that do not run under Windows XP?

The only one I'm aware of is from an unofficial patch: Unreal.
On my Win98 PC I have a DX9 card (FX5200) and with the oldunreal.com patch I can run Unreal in D3D9 with better performance than any other D3D or OpenGL mode in the game.

Nice, that way you get A3D sound as well as good looking graphics...

I never had any trouble using DirectX 9 on Windows 98SE. I use 8.1 mostly.
But if you fancy 9, go for it 😀

swaaye wrote:

I typically run DirectX 7.0a because after lots of experimentation over the years I've found this version to be the last really stable choice. Anything beyond that and I see more frequent BSODs, especially with subsequent launches of 3D programs during a single session.

This sounds more a bad/bugged driver problem than a DirectX library problem. Also, never mix newer Video drivers with VxD legacy drivers like Audio and Joystick. This surely will end in frequent BSoDS. DirectX9 was designed to work in a WDM environment, so supply it with correct WDM Audio/Video/Joystick drivers.

If you need legacy drivers, you will be better served by DirectX 7/8.

clueless1 wrote:

The only one I'm aware of is from an unofficial patch: Unreal.
On my Win98 PC I have a DX9 card (FX5200) and with the oldunreal.com patch I can run Unreal in D3D9 with better performance than any other D3D or OpenGL mode in the game.

In effect, this is the only way to get the best performance and no stuttering from ATi/AMD Radeon cards, at least with this game (and yeah, i still play it 😉).

hyoenmadan wrote:

swaaye wrote:

I typically run DirectX 7.0a because after lots of experimentation over the years I've found this version to be the last really stable choice. Anything beyond that and I see more frequent BSODs, especially with subsequent launches of 3D programs during a single session.

This sounds more a bad/bugged driver problem than a DirectX library problem. Also, never mix newer Video drivers with VxD legacy drivers like Audio and Joystick. This surely will end in frequent BSoDS. DirectX9 was designed to work in a WDM environment, so supply it with correct WDM Audio/Video/Joystick drivers.

If you need legacy drivers, you will be better served by DirectX 7/8.

I think you could be right. The problem is that the WDM 9x drivers for sound cards usually do not produce correct 3D audio. Some cards don't even have WDM options.

D3D8 doesn't work better than 9 though. You specifically need to stay on DX7.0a or below.

I asked a similar question a while back and got a similar mix of responses:

DirectX compatibility problems: fact or fiction?

I always use DirectX 9.0c (Dec. 2006) and have never had any issues. (None that I could trace to DirectX, anyway.)

Graphics and sound drivers seem to be the critical pieces as far as compatibility and stability are concerned.

I also use 9.0c on my Athlon Win98 machine, it was necessary for Tron 2.0. No problems here.

Video and sound card details? Driver versions are useful too. What games and programs have you spent a significant amount of time running?

I'd stick to directx9.0b myself, before they started messing with directdraw.

Seeing about 5 threads about this in the past year or so has me experimenting again.

Thus far I've found one example of DirectX 8-9 being a problem in 98SE. If you run a Vortex 2 card and play Wheel of Time, WoT.exe will completely lock the PC the second time you try to run the game. If I uninstall the Vortex 2 driver (2041) or revert to DirectX 7.0A, this no longer occurs. I tried DirectX 8.0, 8.1, 9.0b and 9.0c and each exhibits this issue.

Lots of games seem to work fine. I recall this being a problem with Sin and Homeworld but I haven't gotten to those games yet. Homeworld Cataclysm works ok though.

So be wary of your old sound card drivers if you must run > DirectX 7.0a.

DirectX 9.0c is required for later made ATi Catalyst drivers.

I've never had a problem with the unofficial DirectX 9.0c installer, I don't remember where I got it from.

notsofossil wrote:

DirectX 9.0c is required for later made ATi Catalyst drivers.

It's not. I know the ATI installer warns you about it but you can definitely run say Catalyst 6.2 with DirectX 7. I was doing this just a few days ago.