Patch per 3D Mark 2003: niente più risultati falsati

Futuremark, software house che ha sviluppato i benchmark 3D Mark 2001 e 3D Mark 2003, ha ufficialmente rilasciato una patch per il proprio benchmark 3D Mark 2003, tool di test sintetico per schede video pensato per sfruttare appieno le potenzialità delle API Microsoft DirectX 9. Di seguito è riportato l'annuncio ufficiale di Futuremark, del 23 Maggio:

Saratoga, California USA May 23rd, 2003

Dear Member of the Press:

3DMark(R)03 incorporates many ground breaking new features and technologies and sets the standard for easily and objectively measuring and comparing modern PCs' 3D graphics performance. Recently, there have been questions and some confusion regarding 3DMark(R)03 results obtained with certain NVIDIA drivers.

We have now established that NVIDIA's Detonator FX drivers contain certain detection mechanisms that cause an artificially high score when using 3DMark(R)03. We have just published a patch 330 for 3DMark03 that defeats the detection mechanisms in the drivers and provides correct results.

You can download the patch here.

A detailed audit report of the drivers and 3DMark03 is available here.

Sia ATI che nVidia sono state accusate da Futuremark di aver introdotto all'interno dei propri driver delle ottimizzazioni miranti ad aumentare le prestazioni velocistiche delle proprie schede con il benchmark 3D Mark 2003. ATI ha risposto specificando che le ottimizzazioni introdotte non portano ad un peggioramento della qualità d'immagine complessiva ottenibile con 3D Mark 2003, ma mirano ad una migliore gestione dei due Shader DirectX 9, sfruttando al meglio le potenzialità delle GPU ATI. ATI ha confermato che per evitare possibili problemi queste ottimizzazioni verranno rimosse dalla prossima versione di driver Catalyst.

nVidia non ha ufficialmente commentato queste informazioni; Futuremark ha comunicato che i driver Detonator 43.51WHQL e 44.03 contengono ottimizzazioni che portano a falsare i risultati ottenuti con il benchmark 3D Mark 2003. Ecco, in dettaglio, quali siano le modifiche driver implementate nei driver Detonator che portano a falsare i risultati ottenuti con il benchmark 3D Mark 2003:

1. The loading screen of the 3DMark03 test is detected by the driver. This is used by the driver to disregard the back buffer clear command that 3DMark03 gives. This incorrectly reduces the workload. However, if the loading screen is rendered in a different manner, the driver seems to fail to detect 3DMark03, and performs the back buffer clear command as instructed.

2. A vertex shader used in game test 2 (P_Pointsprite.vsh) is detected by the driver. In this case the driver uses instructions contained in the driver to determine when to obey the back buffer clear command and when not to. If the back buffer would not be cleared at all in game test 2, the stars in the view of outer space in some cameras would appear smeared as have been reported in the articles mentioned earlier. Back buffer clearing is turned off and on again so that the back buffer is cleared only when the default benchmark cameras show outer space. In free camera mode one can keep the camera outside the spaceship through the entire test, and see how the sky smearing is turned on and off.

3. A vertex shader used in game test 4 (M_HDRsky.vsh) is detected. In this case the driver adds two static clipping planes to reduce the workload. The clipping planes are placed so that the sky is cut out just beyond what is visible in the default camera angles. Again, using the free camera one can look at the sky to see it abruptly cut off. Screenshot of this view was also reported in the ExtremeTech and Beyond3D articles. This cheat was introduced in the 43.51 drivers as far as we know.

4. In game test 4, the water pixel shader (M_Water.psh) is detected. The driver uses this detection to artificially achieve a large performance boost - more than doubling the early frame rate on some systems. In our inspection we noticed a difference in the rendering when compared either to the DirectX reference rasterizer or to those of other hardware. It appears the water shader is being totally discarded and replaced with an alternative more efficient shader implemented in the drivers themselves. The drivers produce a similar looking rendering, but not an identical one.

5. In game test 4 there is detection of a pixel shader (m_HDRSky.psh). Again it appears the shader is being totally discarded and replaced with an alternative more efficient shader in a similar fashion to the water pixel shader above. The rendering looks similar, but it is not identical.

6. A vertex shader (G_MetalCubeLit.vsh) is detected in game test 1. Preventing this detection proved to reduce the frame rate with these drivers, but we have not yet determined the cause.

7. A vertex shader in game test 3 (G_PaintBaked.vsh) is detected, and preventing this detection drops the scores with these drivers. This cheat causes the back buffer clearing to be disregarded; we are not yet aware of any other cheats.

8. The vertex and pixel shaders used in the 3DMark03 feature tests are also detected by the driver. When we prevented this detection, the performance dropped by more than a factor of two in the 2.0 pixel shader test.

Per valutare l'impatto delle ottimizzazioni interne sui risultati prestazionali ottenuti con benchmark 3D Mark 2003 si faccia riferimento a questo articolo pubblicato sul sito americano Hot Hardware

Come si nota chiaramente, utilizzando la versione più aggiornata del benchmark 3D Mark 2003 le prestazioni velocistiche delle due schede calano sensibilmente, in modo particolare la scheda nVidia GeForce FX 5900 Ultra.

Per ulteriori informazioni sul benchmark 3D Mark 2003 si rimanda alla recensione, pubblicata su Hardware Upgrade a questo indirizzo. La nuova patch 330 per benchmark 3D mark 2003 può invece essere scaricata a questo indirizzo, dalla sezione software di Hardware Upgrade.