NF4 and SLI issues?

[loomis2]

In the newest video card price guide, it mentions not going with an SLI setup right now because of new NF4 and SLI issues What are they talking about? After reading their original sli mb reviews and the performance jump they talked about I was all ready to get an a8n-sli and 2 6600gt's. Should I just get 1 video card and wait?

 

[Tripp17]

To be honest, SLI is turning out to be a nightmare......and believe me, i had 2 6800GTs and an A8N-SLI........look at my sig, dont see it anymore do you?

 

[loomis2]

Why? What happened? It seems like a great idea to me and the original Anandtech reviews were VERY favorable. What's wrong with it?

 

[ohnnyj]

I haven't had many issues with my SLI rig. Half Life 2 at 1920x1200 2xAA 16xAF never looked so good on my 24" Sony GDM-FW900.

 

[ChineseDemocracyGNR]

With problems or not, a single 6800GT is a much better option than two 6600GT in SLI.

 

[ohnnyj]

Originally posted by: ChineseDemocracyGNR
With problems or not, a single 6800GT is a much better option than two 6600GT in SLI.

I agree. Two 6600GTs = Single 6800GT + More Heat + More Noise.

 

[loomis2]

So Tripp17 is the only one having problems? I'm just trying to figure out why Anandtech is all of a sudden jumping off the SLI bandwagon.

 

[ohnnyj]

Originally posted by: loomis2
So Tripp17 is the only one having problems? I'm just trying to figure out why Anandtech is all of a sudden jumping off the SLI bandwagon.

Because SLI is still in its infancy and it may be better to just wait a bit and see if nVidia can iron out all the problems before jumping on the bandwagon.

 

[TheInvincibleMustard]

Another possiblity that hasn't been mentioned in this thread is the fact that SLI will only work with games/applications that nVidia has specifically written drivers for. If you've got 2x6600GT's in your machine (as an example) and run a game that is not supported under the nVidia drivers (be sure to pick an obscure one, like, oh ... Everquest II or World of Warcraft ...), you'll only be utilizing ONE of your video cards ...

nZone reference

 

[deadseasquirrel]

Originally posted by: TheInvincibleMustard
Another possiblity that hasn't been mentioned in this thread is the fact that SLI will only work with games/applications that nVidia has specifically written drivers for.

It hasn't been mentioned because it's not quite accurate. You're right, there needs to be settings in the drivers, but nVidia doesn't need to issue them. It's as simple as these 3 lines of code:

<PROFILE Label="New App Name">
<APPLICATION Label="New App.exe" />
<PROPERTY Label="multichip_rendering_mode" Value="2" Itemtype="predefined" /> </PROFILE>

Adding these lines of code for your particular game (and setting the appropriate "Value" based on the rendering mode (or using one of the many tools already created that make this child's play), will allow you to make many many more games work with SLI.

nVidia names like 21 apps in that link. It's missing a few. Right now, I have support for another 50 or so, and the list is growing.

 

[TheInvincibleMustard]

Aha, that's pretty slick. I pretty much gave up on SLI as being not worth it in the long run and/or too expensive initally, so I haven't kept tabs on how it's progressing. That's nice to know that it'll work for many other applications. IMHO, I still think it's too cost-prohibitive at this moment, but good to see that it's not as bad as I had thought it to be. :thumbsup:

 

[ChineseDemocracyGNR]

The question is - how much of an improvement is SLI for a game that is not optimized/supported by the drivers?

 

[deadseasquirrel]

Originally posted by: ChineseDemocracyGNR
The question is - how much of an improvement is SLI for a game that is not optimized/supported by the drivers?

Good question. As you can see from that link, UT2k4 is not listed as supported by nV. Well, it works with AFR rendering with a manual change in the profile. My benches below:

Used U-Mark utility from http://www.unrealmark.net
A64 3000+ stock
single 6800GT 370/1000 (stock BFG)
1600x1200 with 4x AA 8x AF forced in the drivers

Map 1-- 57.61 FPS
Map 2-- 95.39
Map 3-- 44.32
Map 4-- 104
Map 5-- 56.59
Map 6-- 48
Map 7-- 64.19
Map 8-- 54
Map 9-- 65.77

A64 3000+ stock
SLI GTs 370/1000 (stock BFG)
1600x1200 with 4x AA 8x AF forced in the drivers

Map 1-- 75 (23% increase)
Map 2-- 157 (39% increase)
Map 3-- 62 (29% increase)
Map 4-- 104 (0% increase)
Map 5-- 74 (23% increase)
Map 6-- 48 (0% increase)
Map 7-- 93 (31% increase)
Map 8-- 54 (0% increase)
Map 9-- 66 (0% increase)

It appears that I was CPU limited on some of those maps as when I overclocked to 2500mhz, it opened up a little more. I don't have benches of a single 6800gt with the overclocked CPU though, so these aren't exactly apples to apples:

A64 3000+ @ 2500mhz
SLI GTs stock 370/1000
1600x1200 with 4x AA 8x AF forced in the drivers

Map 1-- 95 (39% increase) total increase over single GT
Map 2-- 157 (44% increase)
Map 3-- 62 (41% increase)
Map 4-- 104 (23% increase)
Map 5-- 74 (40% increase)
Map 6-- 48 (24% increase)
Map 7-- 93 (43% increase)
Map 8-- 54 (24% increase)
Map 9-- 66 (24% increase)

The % increase (when compared apples-to-apples with the stock CPU) for UT2k4 doesn't quite equal the % increases I've seen in games that "officially" have the nV stamp, such as Far Cry, HL2, and Doom3... which all saw gains of around 40% at the stock CPU. It wasn't until I overclocked the 3000+ that I saw 40% gains.

But, this may not be a fair example to compare "officially" nV-supported games vs. unofficial since UT2k4 is known for being CPU-dependent.

 

[gixxer]

Originally posted by: deadseasquirrel

Originally posted by: TheInvincibleMustard
Another possiblity that hasn't been mentioned in this thread is the fact that SLI will only work with games/applications that nVidia has specifically written drivers for.

It hasn't been mentioned because it's not quite accurate. You're right, there needs to be settings in the drivers, but nVidia doesn't need to issue them. It's as simple as these 3 lines of code:

<PROFILE Label="New App Name">
<APPLICATION Label="New App.exe" />
<PROPERTY Label="multichip_rendering_mode" Value="2" Itemtype="predefined" /> </PROFILE>

Adding these lines of code for your particular game (and setting the appropriate "Value" based on the rendering mode (or using one of the many tools already created that make this child's play), will allow you to make many many more games work with SLI.

nVidia names like 21 apps in that link. It's missing a few. Right now, I have support for another 50 or so, and the list is growing.

this is good info... but it also makes you wonder. If it is this easy to do, why hasn't Nvidia done this. Or at least made a generic option that forces SLI for games.

 

[Sqube]

Originally posted by: gixxer
this is good info... but it also makes you wonder. If it is this so easy to do, why hasn't Nvidia done this. Or at least made a generic option that forces SLI for games.

That was my concern. I'm wondering if there's something else they're doing that they aren't talking about. Doubtful, but still...