They say two is better than one, and who am I to argue? how many of you are old enough to remember blowing a few months wages on two Voodoo 2's then using them in SLI to play Tomb Raider?
Ive been playing this week with an FX-55 powered Nvidia 6800 ultra SLI setup, and im sure some of our members are in the lucky position to have a similar setup. When Nvidia first released this remake of 3DFX technology it was very hampered by shoddy driver support, but thankfully with the release of the
new 71.84 drivers we now have over
60 games offically supported with this technology.
The gaming community asked Nvidia if they could make their own profiles and thankfully they have offered this option to the end user. some of you may already be aware of these "self made" profiles from editorials like
this one at Hardocp, but for those who arent, ill talk you through setting up a profile for a new title not offically supported and recording any gains from doing so.
Firstly, a great resource for up to date information is available at
www.slizone.com - this site not only has breaking information regarding SLI but has a list of supported games with the latest drivers as well as information on the technology behind SLI.
Firstly install
forceware 71.84
If you dont have coolbits installed, follow these instructions to setup profliing options.
Start button and select Run. When the command box opens, type "regedit" (without the quotes) and press OK. With the registry open, go to HKEY_LOCAL_MACHINE \SOFTWARE \NVIDIA \Corporation \Global \NVTweak. Once there, right-click inside the right window, and choose "New>DWORD value". Name the value "Coolbits" (without the quotes). Within the Registry Editor, right click on Coolbits and choose Modify. Change the Value data to "8" (without the quotes) and click OK.
courtesy slizone
We are going to associate a multi GPU rendering mode with Atari's excellent ACT OF WAR. From within the Nvidia control panel click on "Performance and Quality Settings"
From this window browse to the EXE for Act of War, which would be c: program files/Atari/Act Of War - Direct Action/ACTOFWAR.exe
There are various rendering modes now to choose:
AUTO SELECT
ALTERNATE FRAME RENDERING
SPLIT FRAME RENDERING
ALTERNATE FRAME RENDERING 2
SINGLE GPU RENDERING
As this game is not yet coded into the drivers with a specific mode, it will have defaulted to Single GPU rendering for maximum compatibility. So therefore we will try some modes. Enable the SLI load balancing option as this will show onscreen during testing.
The first mode I tried was split frame rendering which gave no gains (measured with the new version of fraps - now compatible with SLI), and while watching the GPU LOAD balancing (a green translucent vertical and horizontal bar, depicting loads across both GPUS), the green bar moved to the bottom of the screen meaning the primary GPU was handling all the rendering.
Next I moved to Alternate Frame rendering 1/2 and noticed that although there was minor screen corrupt as the game loaded, once in game everything ran perfectly smoothly with massive gains in game.
1600x1200 all settings maxed - ACT OF WAR.
AMD FX55
XFX 6800 ultra x2 / 1 gig OCZ 3200DDR 5-2-2-2 1T
OCZ 520w Powerstream
ASUS A8N SLI DELUXE (1006 bios).
NO OVERCLOCKING.
So we can take from this that SLI is now starting to come of age and the fact Nvidia are putting the end user into the game with controllable rendering options via Forceware 71.84 can only be seen as a wise move on their behalf, this means even if the game is not yet offically supported with a prebuilt Nvidia Profile, you can sit and play with the various options and the newest version of FRAPS to see how the gains will work in your favour. With regards to the Act of War results above, the minimum frame rates are affected by the loading of video in game, this seems to hit both the 6800 ultra in single GPU mode and the X8xx series cards equally in game, but yet with two GFX powering the game this was barely noticeable.
How about compatibility with your older collection? Well not
everything works from the wide list ive tested, but ive had great results with a variety of games and primarily the "Alternate Frame rendering 2" mode. Id say 80-90% of the games ive tested with have had gains in some shape or form with one of the various rendering methods.
It really is good times for Nvidia right now and it takes me right back to my youth when I was sitting in my computer room with two Voodoo 2's in SLI watching those oversized polygons of Lara's bouncing around onscreen.
I can safely say, even though I do tend to favour ATI hardware that this really does take some beating when you get a game successfully running in SLI mode, after beating "Spinter Cell - Chaos Theory" on a BBA X850XTPE ive been enjoying replaying it at
1600x1200
HDR rendering on
Tone Mapping on
Parallax Mapping on
High Quality soft shadows on
SM3
Aniso 16x
with frame rates constantly in the 50-80 zone !
So, how will ATI answer this? well they usually dont sit for long in second place........