[A.L.M.]

Originariamente inviato da Scrambler77

...beh beh... questa è una teoria tutta da dimostrare... anche perchè non si conoscono neanche le reali prestazioni di G80 in dx10.

Beh, alcune cose stanno trapelando... R600 sembra avere Geometry Shaders nettamente più potenti di G80.

Presunto test con DX10. I valori DX9 sembrano troppo bassi per tutte le schede, ma quelli DX10 sembrerebbero confermati da varie fonti...

Driver: 8.37-4, CPU: E6700, from europes biggest PC-Magazine ct

Oblivion, HDR on

1280 X 1024 noAA/noAF

2900 XT 49 fps
88 GTS 48 fps
88 GTX 48 fps

1280 X 1024 AA 4X / noAF

2900 XT 39 fps
88 GTS 46 fps
88 GTX 48 fps

1280 x1024 AA 8X / noAF

HD 2900 XT 17 fps
88 GTS 28 fps
88 GTX 39 fps


PREY

1600 x 1200 AA 8X / AF 16X

HD 2900 XT 43 fps
88 GTS 37 fps
88 GTX 50 fps


Windows Vista Direct X10 SDK

PIPEGS

2900XT 159 fps
88GTS 34 fps
88GTX 63 fps


CubemapGS, Car, Instancing

2900XT 23 fps
88GTS 9 fps
88GTX 11 fps

Cubemap, Car, Instancing

2900XT 18 fps
88GTS 10 fps
88GTX 11 fps

Given the state of the NV drivers for the G80 and that ATI hasn’t released their hw yet; it’s hard to see how this is really a bad plan. We really want to see final ATI hw and production quality NV and ATI drivers before we ship our DX10 support. Early tests on ATI hw show their geometry shader unit is much more performant than the GS unit on the NV hw. That could influence our feature plan.

http://blogs.msdn.com/ptaylor/archiv...mean-dx10.aspx

Hello Everyone,

This is a fairly generic question, and I promise it may sound like a hardward question at first, but it's not really. Does anyone else notice how slow some of the DX10 samples in the Feb SDK are? Specifically those that employ the geometry shader such as the displacement mapped lizard and the example of how to do cube mapping in one pass (when you check "Render Car")? They are dramatically slower than other DX10 and DX9 samples. I was shocked when I ran them.

Do you think this is because the DX10 SDK/API is in it's infancy? Or the hardware/drivers are still too young? I'd ask this in a hardware forum but most of those guys don't know anything specific to the SDK or programming, just the buzz words and marketing numbers that come from Nvidia.

Both of these samples run at about 5-10 FPS on my machine. Not to turn this into a hardware question by any means, but my system is a brand new dual core w/8800 GTX and 100.64 drivers. I expected the GS pipe to be much faster.

http://forums.microsoft.com/MSDN/Sho...59714&SiteID=1

Originally Posted by AndyTX
Aha - this seems to be confirming my theory that if R600 is faster anywhere, it will be in geometry shading. Granted G80 still has a lot of space to improve in that area: a recent test that I did indicated that even having *any* geometry shader present (I used an "identity" geometry shader that just passed through the triangles) cut the performance of the shader in *half*.

http://forum.beyond3d.com/showpost.p...postcount=5272

Originally Posted by Rys
Currently it seems to be that if any GS shader is scheduled, the hardware will decrease the number of threads running for the other types indiscriminately. That's the driver doing that, though (as far as I can tell), rather than something at the hardware level.

http://forum.beyond3d.com/showpost.p...postcount=5280

Ovviamente è ancora tutto da confermare/capire, ma sembrerebbe che le performance dei GS per ora su G80 siano troppo basse. Non si sa ancora bene il perchè, se questo è un problema hardware o software, però.
Inoltre è da capire quale e quanto intenso sarà l'uso dei GS nei giochi DX10 di prima generazione.