Gmod utilizes one out of 2 graphics cards even in SLI mode

Hey wonderful users of FP I need a little help.

I’ve recently noticed this. Basically, my computer is only using 1 of my 2 NVIDIA GeForce 9800 GTs when I play Garrysmod.

I have a program that shows me the temperature, fanspeed and usage of my two graphics cards. When I play any source game, like Counter-Strike: Source, I see that both graphics cards are being used equally and both fans are on to reduce their temperature. (By the way my cards ARE in SLI mode)

However, when I run garrysmod, only the first of my two cards shows any sign of usage. I really have no idea why this is so, and i could not find information on this anywhere else. I apologize if this has been posted before.

I’ve recently updated my drivers, and checked my 3d settings in the Nvidia control panel. If anyone has any idea why this is so please let me know or give me a suggestion. Thanks!

My PC specs are as follows

Vista Home Premium
Intel Core 2 Duo E8500 3.16 GHz
3068 MB RAM
NVIDIA GeForce 9800 GT (2)
1680x1050 LCD monitor at 60Hz
DirectX Version: 11
NVIDIA Driver version 258.96

Any help is greatly appreciated!

I can’t help ya, but if it will help other figure out the problem you might want to do this:
Go to the “Start” menu > run > dxdiag. There should be a section bout your video card and how they do shit. Copy/pasta or screenshot that!

What would you use more than one graphics card for? :raise:

Why would you need a CPU with 2 cores? Or even four cores?

It’s just for extra power, although when I get my next computer I think I would go with one very powerful card rather than two fairly good cards.

Hahaha, I actually posted my computers specs while reading off of dxdiag, let me go screenshot that and post it up. Maybe I missed something.

Still though, when I play most games it uses both, including other source games. I should see if HL1 and older games use both of my cards. Anyway, if anyone else reading this knows, give me some infooooo. Maybe Garry knows you can’t use SLI with gmod. Garry?

mah specz

Sorry to bump this but I really can’t find any information on this. I reset some nvidea preferences on hl2.exe but it didn’t do anything.

This seems to be specifically gmod related. Other source games are not affected. I’d really like this solved as I would really like to make use of the cash I spent buying my two cards.

Maybe some hack to make Gmod think it’s one card when they are both running?!

Does this happen with any other games? (besides Source)

My guess is that the source engine doesn’t support SLI mode.

I doubt Source supports dual GPU’s. I may be wrong, though.

It doesn’t happen with any source game. Or any of my other games I’ve checked this with so far.

Did either of you even read my first post…? -_-
This ONLY Happens When I Play Garrysmod.
All other source games I have utilize Both of my Cards.
It’s gmod, not source.


Anyone notice this problem. Download EVGA Precision or some program that you can monitor your video cards with. Anyone else have cards in SLI mode?

Let me know if you do…

It’s been almost a year now. So here’s a giant fucking bump. I’ve found ZeRo information on this topic.

Is there someone out there who knows about this now? I googled this problem and the first thing on the list was my old forum topic. Lmfao. I’m going to murder myself.

Doesn’t it run good enough as is with only 1 card? I’ve got a 9600 and I run max settings fine, and my specs are very close to yours.

I need …the POWWAAA. But seriously, yes it runs fine, I’ve been playing it forever. Maybe I shouldn’t complain, I just thought it would be awesome to use the two video cards I bought. Kind of a waste of Benjamins ($100 bilz). You knaimean?

Are you running gmod in windowed mode? If so, it wont probably work. If you really need the power (i doubt it) force alternate rendering mode in the nvidia control panel and experience a whole world of glitches and shit.

Source Engine limitations most likely.