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Performance hit, is it on graphic card or CPU side?

Posted: Sat Jan 10, 2009 3:39 am
by snaileri
Hi.
When 3D is turned on (shutterglass), does the image's double-rendering affect both CPU and graphcard performance, or is it just on graphcard side?
I have 8800 GTX 768 and I'm about to buy one of the new 120hz monitors, and I'm unsure if the card is able to hold good frame rate at 1680x1050 resolution.
If the 3D affects CPUs performance too, then 3D is no no for me, because then I'd have to upgrade my whole system.

My CPU is Q6600 2,4ghz

Thanks for any replies!

Re: Performance hit, is it on graphic card or CPU side?

Posted: Sat Jan 10, 2009 4:15 am
by Likay
As always it depends on what games you're playing. If you have bad performance in 3d you need to tunr some option down. For example the resolution. The performance hit in 3d in regards to 2d should be somewhere in between 10% and 50%. Different games gives different fps performancehits. So far if you use shutterglasses with the iz3d drivers and your 8800 the fps from the game have to be at a stable rate to perform well with shutters (left/right eye shifts otherwise). The support for stereo-3d in games sank like a stone when nvidia introduced their 8000 series of card (and upwards). Some have managed shutterglasses with 8800's: http://www.mtbs3d.com/phpBB/viewtopic.php?f=7&t=1072" onclick="window.open(this.href);return false;

Re: Performance hit, is it on graphic card or CPU side?

Posted: Sat Jan 10, 2009 6:23 am
by Tril
I can't say in your specific case but in general, the most important is the video card.

If I had to choose between:
  • Slow cpu with fast video card
  • Fast cpu with slow video card
I would choose the slow cpu with the fast video card. Of course, I would prefer a fast cpu with a fast video card.

I just upgraded from a Nvidia 8600 to an ATI 4850 and the performance boost is amazing. You could try to take a look at game benchmarks and look for the fps.

If you plan on buying the 3D Vision shutterglasses, it does not matter if your card can't render at 120 Hz all the time. The NVIDIA stereo driver is able to keep the latest left and right frames in memory and always switch them at 120 Hz no matter the game fps.

Re: Performance hit, is it on graphic card or CPU side?

Posted: Sat Jan 10, 2009 6:55 am
by snaileri
Thanks.
So my rig should be enough to run Left 4 Dead at 1680x1050 in 3D. Resolution is the least I want to reduce, maybe I remove dynamic shadows if my FPS goes below 35 or so.
Oh well, it's still a long way until we european get our hands on those glasses.

Re: Performance hit, is it on graphic card or CPU side?

Posted: Sat Jan 10, 2009 8:39 am
by BlackShark
3D rendering is mostly done with the GPU.
So you should expect a 50% framerate reduction.

That is unless the 2D rendering maxes out your CPU (completely game dependant).
In these cases you'll get less framerate reduction and you can expect anyhting between 0% and 50% reduction.

Note : the iz3d driver needs to hack the rendering process to access the camera so there is a framerate reduction straight away just for using the iZ3D driver.
This framerate reduction is about 10-20% depending on the games. I haven't found a game so far which doesn't have this issue with iZ3D.

I do not have the nvidia drivers since i'm running winXP so i cannot test myself but according to the data from the benchmark seciton and other websites benchmarks (from the Geforce 3D reviews) nvidia drivers don't have this issue since they act at the driver level.

Re: Performance hit, is it on graphic card or CPU side?

Posted: Mon Jan 12, 2009 6:03 pm
by BILDO
Snail... so have u done it yet??? I totally wana play Left 4 dead in 3D... like that would be the poop.

Re: Performance hit, is it on graphic card or CPU side?

Posted: Sat Jan 17, 2009 2:24 pm
by snaileri
I'm still waiting for Nvidia's glasses to get in the markets here in EU.
And I need a new screen too.