Om Radeon X1900

Ursprungligen inskrivet av Nyhet
Radeon X1900 XTX i Crossfire tillsammans med ett Radeon X1900 XT Crossfire rapporteras ge bättre prestanda än två GeForce 7800 GTX 512MB i SLI.

Ursprungligen inskrivet av XCan
Nu tycker väl alla som håller på att vänta på x1900 att det är lika bra att vänta på GF7900 samtidigt som de tycker att folk som inte väntar bara försöker motivera sina dåliga köp...

Ursprungligen inskrivet av XCan
Nu tycker väl alla som håller på att vänta på x1900 att det är lika bra att vänta på GF7900 samtidigt som de tycker att folk som inte väntar bara försöker motivera sina dåliga köp...

Ursprungligen inskrivet av arky
7900 tar det nog men frågan är om det tar ett GT/GTX/Ultra.

Ursprungligen inskrivet av Milo
X1900XTX vinner helt klart med tanke på den s.k sofisterkade background tekniken som pryder ati korten. Vilken i sin tur leder till celosav transplantering av energi strömmar som i sin leder till bättre prestanda, och med tanke på atis inbyggda ANOP teknik så kommer detta kort utklassa 7900, därför att den helt enkelt presterar maximalt sett till prestandan.

"proffessor skitsnack"

http://www.firingsquad.com/hardware/3dmark_06/page8.asp

AMD Athlon 64 FX-60
NVIDIA GeForce 7800 GTX 512MB

3DMark06 1280x1024x32 SM 2.0 = 2162
3DMark06 1280x1024x32 HDR/SM 3.0 = 2203

http://forums.vr-zone.com.sg/showthread.php?t=53164&page=6

AMD Athlon 64 FX-60 @2616 MHz
ATI Radeon X1900XT

3DMark06 1280x1024x32 SM 2.0 = 2081
3DMark06 1280x1024x32 HDR/SM 3.0 = 2279

Ursprungligen inskrivet av DataNusse
Jag är helt säker på vem som kommer vinna i G71 vs R580. Men jag tänker inte säga vem.

Ursprungligen inskrivet av S_Z
3DMark06 borde vara väldigt pixelshader krävande tycker man ju och borde passa X1900XT med alla sina pixel shaders men trots det så lyckas det bara med nöd och näppe hålla jämna steg med 7800GTX 512Mb. Är det helt begränsat av nåt annat? Skall bli intressant att följa diskusionerna tycker jag... om dessa värden stämmer dvs.

Kanske är ATIs tur att gå ut med pressmeddelande "3DMark betyder ingenting, bry er inte om det"

Tycker man får mer och mer känslan av att R580 inte kommer erbjuda så värst mycket mer än sin lillebror. Man får ju hoppas för ATIs skull att de får ut korten i tid och att nVidia inte får ut sina 7900 förräns i mars för ifall det här stämmer lär de ju få mycket svårt mot 7900.

Jaja man får väl hålla sig till tåls några dagar till innan man vet med säkerhet.

The new 3DMark uses several of the same game tests as 3DMark05, updated to increase the graphics workload, and using a new 3D engine with a major new shadow algorithm, called Cube Shadow Maps. Futuremark's new shadow method works by dividing the view frustum into five sections along the z-axis. Each section gets shadowed by a standard uniform 2048x2048 shadowmap. If the hardware supports depth textures, a D24X8 or DF24 depth map is used. If these texture formats are not supported, an R32F single component 32-bit floating-point texture will be used as a depth map. Shadows from point light sources use a 1024x1024x6 cube map of the format R32F as depth map, unless the hardware supports D24X8 with hardware bilinear PCF or DF24 with FETCH4 depth textures. You can really notice the difference in the game tests, where the shadows are much smoother, more natural, and lifelike.

According to ATI, a 16-bit depth stencil texture (DST) would have been sufficient to preserve quality in 3DMark06. Futuremark does not use DSTs on current ATI cards since they do not support the D24X8 format—instead they render into a 32-bit floating-point color buffer and use it as the depth texture. When generating the shadow buffers on an X1000 cards for each pixel, ATI has to read and write to a 32-bit depth buffer, and also write to a 32-bit color buffer for a total of up to 96-bits per pixel of bandwidth. Had Futuremark chosen to use 16-bit DSTs, ATI (and Nvidia) would need at most 32-bits per pixel of bandwidth. It's possible that a future card from ATI may support the D24X8 texture format."

In 3DMark06 we require 24-bit z-buffers at minimum to ensure that the quality and accuracy of the shadows are top-notch in all surroundings throughout the benchmark (during the benchmark, the demo and the game). During the development of 3DMark05 we made research into using 16 bit z-buffers, but noticed that the accuracy was not sufficient for the shadow technique we used. In 3DMark06 we use a new shadow technique, which is much better and more robust than the one in 3DMark05, but there are still cases where 24-bit z-buffers are barely enough. There are of course some cases and places where 16-bit z-buffers might be suffice, but to make sure that we do not get different rendering output with different hardware we require 24-bit z buffers for all hardware. 24-bit z-buffer is much more robust, and it ensures that the quality of the shadows is at the level we require.

Still, we're left with quite a few worrisome questions. We can understand that Nvidia graphics cards won't run the SM3.0 tests with anti-aliasing—the hardware simply does not support floating-point blending together with AA (at least without using the pixel shaders for a very slow hack). We can't figure out why this should prevent those cards from producing a score, though. There's a formula for generating a 3DMark score using just the SM2.0 and CPU scores—why wouldn't a GeForce 7800 GTX card use that formula when AA is enabled? A GeForce 6200 supports SM3.0 but not floating-point blending. We still consider that a SM3.0 card, and yet it uses the formula for SM2.0 cards because it does not support the FP16 blending required for the SM3.0 + HDR tests. Why the discrepancy? Why doesn't the GeForce 6200 just produce no score? The rules are different when AA is enabled than they are when it isn't.

Nvidia likely believes that having no score is better than having a low score. According to Tony Tamasi, Nvidia believes that an "NA" (not applicable) is the correct way to report the score.

Then there are the 24-bit depth stencil textures. This is supposedly an optional format in DX9, and yet it is required by Futuremark's new shadow algorithm. Only Nvidia supports this format, but rather than using a 16-bit depth stencil texture on ATI cards, they're forced into a costly workaround. If ATI is forced into a costly workaround for the depth stencil texture format, why isn't Nvidia forced into a costly workaround for HDR + AA? Here we have a major hardware manufacturer claiming that the 24-bit format for the DST is not required to preserve shadow quality, nor that it is commonly used by game developers. Futuremark claims that it is necessary. We'd like to see the benchmark using 16-bit DSTs just to compare quality and judge for ourselves.

Ursprungligen inskrivet av Curly
Här är den troliga förklaringen

Resultatet blir, om jag förstår det hela korrekt, att R520 använder 92bitar bandbredd per pixel för detta medans RV5xx samt G7X endast behöver använda 48bitar bandbredd

Så här svarade FM när dom fick frågan varför dom använde tekniken i fråga

Lustigt nog stödjer RV530 och RV515 24-bit depth stencil textures medans R520 inte gör det.

Det låter ju minst sagt udda. Ska bli intresant och se om ATI släpper en...ehm... "Patch" där deras kort använder 16-bitars z-buffrar (eller vad det nu heter).

Alla citat tagna från http://www.extremetech.com/article2/0,1697,1912116,00.asp