Advertisement Jump to content
Sign in to follow this  
remigius

[MDX/HW] Poor performance with hardware instancing on GeForce7800

This topic is 4641 days old which is more than the 365 day threshold we allow for new replies. Please post a new topic.

If you intended to correct an error in the post then please contact us.

Recommended Posts

I was just bragging about my instancing sample over in Jack's thread and I decided to check what framerate I get now that I've upgraded my machine from a Radeon X850 to this GeForce7800... I guess the result serves me and my big mouth right, since the performance was very poor :p Anyway, I'm referring to my MDX hardware instancing sample, which used to get about 45 fps on my X850, but on the 7800 it only achieves a framerate of about 4 fps. This is unexpectedly low, in fact the constants instancing path (essentially a batch size of 1) is actually faster. The C++ DXSDK instancing sample seems to work just fine, but the NVidia SDK sample does seem to have some issues with performance when spawning about half the allowed number of both models. Rendering the maximum number of a single model seems to work just fine. I shouldn't need to set any additional renderstate and/or other options to take advantage of the hardware instancing technique on this SM3 card, right? I've had some trouble running other (NVidia) demo's, so I'm afraid it might actually have something to do with my card (specifically, I'm wondering if my PSU might be to weak under heavy load). I'm quite stumped though, so any feedback would be much appreciated. Thanks and for Karma's sake, sorry for the thread hijack Jack [wink]

Share this post


Link to post
Share on other sites
Advertisement
Well I just ran it on my geoforce 7900gtx and am getting 58fps average?
using 84.56 drivers

[Edited by - daviangel on May 4, 2006 5:12:10 AM]

Share this post


Link to post
Share on other sites
I had a problem with instancing on a 6600, where it caused my machine to stop responding. However, it hasn't happened lately. Don't know if it's the newer drivers or just shuffling of code that made the card or drivers happier.

However, there's no real need to do anything special. I mean, on older ATI cards you had to do something special to enable instancing, but on NVIDIA you never did.

Share this post


Link to post
Share on other sites
Thanks for trying the sample and the other info, much appreciated! Anyway, I forget to mention explicitly that it's the hardware instancing sample that causes the problems (shader instancing also gives some 59 fps on my machine). If that's already the one you've tried though (@daviangel), at least I can be sure my system is causing this probs and not the sample.

I just reverted from the 84.21 drivers to the standard drivers for this Dell system (77.52). This solves the major problems I had with the Nalu demo and seems to improve performance on other apps, but my instancing sample still only gets 4 fps. Could anyone let me know the performance they're getting with a similar card on the NVidia SDK instancing sample running on the default setting of 500ships/4000rocks. This would help me sort out if my card only has a problem with my sample or with any instancing.

Thanks again!


Edited: I just rechecked the whitepaper on the NVidia SDK instancing sample and the performance I get there seems to be a bit lower than expected. The 6800 should get 35-45fps for 500ships/4000rocks, while I'm getting 30-35fps for the same number of models.

[Edited by - remigius on May 4, 2006 6:03:51 AM]

Share this post


Link to post
Share on other sites
I just checked your hardware instancing sample this morning (following your bragging in jake's thread ^^) and I had 50 FPS.

I've got a GeForce 6800 GT.

Share this post


Link to post
Share on other sites
That sucks, as it would seem there really is something wrong with my system then... Time to contact the "Dell Escalation Team" to which their Customer Care directed me [lol]

Thanks for the help at any rate!

Share this post


Link to post
Share on other sites
Sign in to follow this  

  • Advertisement
×

Important Information

By using GameDev.net, you agree to our community Guidelines, Terms of Use, and Privacy Policy.

GameDev.net is your game development community. Create an account for your GameDev Portfolio and participate in the largest developer community in the games industry.

Sign me up!