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Shader Operations

Short Version

The number of pixel shader operations that can be performed per second.

NOTE: The way we do this calculation is different for DX9 and DX10 cards to accommodate unified architectures. DX9 cards and DX10 cards are *not* directly comparable based on the specifications we've provided here. To compare DX9 and DX10 cards, rely on benchmarks only. 

Long Version

Pixel shaders are programs that are run on the GPU to add some visual effect to a scene. The number of shader operations per second indicates how quickly the card can perform these operations and, in turn, render a scene.

Newer games are becoming increasingly shader intensive and this number is becoming more and more important.

Though it's not a perfect indicator of performance, all else being equal, a card with more pixel shader processing power will outperform a card with lower pixel shader power. As games get more and more shader dependent, cards with more shading power will pull farther and farther ahead of competing cards.

A perfect example of this phenomenon is the X1800 XT and the X1900 XTX. Both cards have nearly identical specifications, with the exception of shader processing power. The X1900 XTX has 3 times the shader processing power of the X1800 XT. This change alone is enough to make the X1900 XTX nearly twice as fast as the X1800 XT in shader-heavy games.


12 Comments
Tuesday, June 27, 2006 10:56:28 AM
fellix
guest
All G7x and NV4x based GPUs (and hense - cards) have 2 (primary and secondary) shader ALUs in each pixel pipeline, so their theoretical shader performance should be acounted respectively. This applies also to all R5xx GPUs from ATi.
Monday, May 21, 2007 9:42:10 PM
Jameson
guest
How come the 8800 GTX and ultra sports a lower shader ops number than ATI's HD 2900 XT but is far better in performance? i don't get it? what accounts for the difference?
Monday, May 21, 2007 10:00:59 PM
Mike
GPUReview Founder
@fellix: I agree, I'll get to it eventually.
Monday, May 21, 2007 10:02:31 PM
Mike
GPUReview Founder
@Jameson: The 8800 GTX is scalar, and thus 100% efficient. The HD 2900 XT is 5-way super-scalar, which means that if instructions cannot be scheduled to execute in groups of 5, performance is lost. So while the HD 2900 XT has much higher theoretical capabilities, its real-world performance is quite a bit lower (or so it would seem).
Wednesday, May 30, 2007 5:25:27 PM
anonymous
guest
Which can be fixed with better newer drivers . I hope ATI/AMD pulls it's act together soon .
Wednesday, September 19, 2007 9:21:25 AM
Radiator
Senior Member
New drivers can't fix broken Multi Sampling Hardware units .
Thursday, October 25, 2007 6:03:27 PM
anonymous
guest
"How come the 8800 GTX and ultra sports a lower shader ops number than ATI's HD 2900 XT but is far better in performance? i don't get it? what accounts for the difference?"

The 2900 series' shaders are not that effecient, essentially they're 64 shaders which can do 5 things at a time, if this isn't optimized correctly, the 2900 series cards can't fulfill their theoretical specifications.
Tuesday, November 13, 2007 9:52:10 AM
AcoQ
guest
Same for the 2600XT?
Thursday, November 15, 2007 4:24:54 PM
anonymous
guest
Yep, this goes for: 2400 Pro, 2400 XT, 2600 Pro, 2600 XT, 2900 GT, 2900 Pro, 2900 XT, 3850 and 3870.
Saturday, November 24, 2007 10:57:54 AM
Radiator
Senior Member
I'd like to see the performance on those cards when they are optimized correctly ... but I think ATi will dump the superscalar architecture before that ... or double the shader processors on it .
Tuesday, November 27, 2007 8:02:58 PM
anonymous
guest
Another issue is with the game creators. Games use Nvidia as the standard for their game testing and programming, so the MADDx5 will have to be optimized on the driver end, even though it shouldn't be. Some games do optimize their proformance for either Nvidia or ATI. As a result you will find games that ATI will be the best and others where Nvidia will be the best. Random stuff like this is why you get some "strange" results on game benchmarking. This is why benchmarking is done on 3 or more games and at various screen settings.
Saturday, March 01, 2008 7:21:43 AM
GPU Expert
guest
A defination for ATi's SuperScalar processing: Remember Intel's HT technology? ATi is doing about the same thing, a processor doing more than 1 thing simultaneously, just only ATi's super scalar means each processor doing 5 things at a time, or known as parallel processing which I studied in Computer Science. Actually the truth is that nvidia's 8800 have 64 Shader Processor doing 2 things simultaneously, so it is known to have 128 shader processor, so it's more efficient than the SuperScalar, remember Pentium4 HT vs. the Pentium , PentiumD owns Pentium4 HT because of it's real Dual-Core while Pentium4 HT is using scalar to make the OS think you're hooked by 2 processors.....
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