If I was going to get a 3870 (and I probably will once the newer non reference cards are out - like the HIS ICQ 3) it would be for: better compatibility with my ATI 650 tuner; lower noise at idle; much better multi-card performance ( Crossfire multiplies performance factors much better than SLI); better HD/Blu Ray performance; better use of multiple displays in a HTPC config, HDMI connections (although it doesn't use the best HDMI standards as yet); a different grahic/image quality some consider better. Of course along with the things I consider positives are the ATI drivers that always seem to light up my "Event Viewer" in mysterious ways. I have lost whole weeks of my life futzing with ATI All-In-Wonder card drivers.
My impressions of ATI cards are that they put more of an emphais on things like drawing and geometry tasks (sometimes a reason given for ATI drivers being buggy- more mathmatically complex) while NV juices some texturing more. Nvidia can skip on drawing to get the frame rates up. Two recent reviews mentioned this trait with regard to Crysis:
"Even the latest NVIDIA driver didn't fix one serious bug: reflections on water are drawn with a big delay, that is there is a certain lag inside a scene. It has to do with optimizations for this game - if you rename the EXE file of the game, this lag disappears, but the game becomes slower. That is NVIDIA developers draw reflections with the lag of several frames. That is, one draw, five skips. That's why reflections are jerking, which produces an impression of lagging. "
http://www.digit-life.com/arti...o/g92-part3-page2.html
Reviewer added latter:
About CRYSIS. "Yep, about those optimizations, because of which reflections on the water are not drawn each frame. It spoils the overall impression, although it appears only in DX10 Very High mode. As if the developers were desperate to accelerate the game. And they did it haphazardly.
When the article was ready to be published, we received information from BFG Russia that NVIDIA promised to fix all problems in CRYSIS in the official release of drivers by the time the game comes out officially. "
Another reviewer mentioned this same problem ( and included pics):
"We found ATi HD3870 is actually has better picture process while Crysis benching. Specially the light refraction from water, HD3870 is very smooth but 8800GT is not. It is around frame 500 to 1000."
http://iax-tech.com/video/3870/38704.htm
Reviewer was then informed about the "fix" for water issue and saw fps go down:
"I don't know what nVidia do to 169.04 but we can see the MAX FPS drops from 30 to 20FPS and the max frame is same as ATi 3870."
http://iax-tech.com/video/3870/38705.htm
I think Nvidia absolutely clips some Image quality to gain performance and that's not been any secret. But Nvidia is still quality card of course. Besides there are people who like the faster frames for shooting and such and don't mind clipped image quality - in fact they will often clip it themselves and leave filters off etc. Its probably hard to see difference most times bewteen mostly equal cards. However the emphsis that can be put on some benches just isn't what it can look like because the makers do have some different approaches that dont compare just like apples and oranges etc.
Here's an older article that predates the NV 8000 series of cards but it gives some insights till into the different approaches and uses pics:
http://www.digit-life.com/arti.../quality_settings.html