SLi or No SLi?

[JDawggS316]

Bottom line: Is it worth it?

Does having 2 GPU's mean better graphics (i.e. 2 512MN VGA's = 1GB)?

Or is it something that isn't all that benifitial and just more costly?

 

[emceepecks]

If you like to play games a lot and demand high FPS while using high settings, it's totally worth it.

And yes, two 512mb cards would make for 1gb of video ram.

 

[squashfx]

Bottom line: Is it worth it?

Does having 2 GPU's mean better graphics (i.e. 2 512MN VGA's = 1GB)?

Or is it something that isn't all that benifitial and just more costly?

depends on the size of your resolution for 1 and for 2 it depends on what gpu's and for 3 it depends on if you play high graphical gaming

 

[jivetrky]

If you like to play games a lot and demand high FPS while using high settings, it's totally worth it.

And yes, two 512mb cards would make for 1gb of video ram.

SLI is good if you have a higher resolution display (1680x1050 or higher) to fully take advantage of the cards. Also, if they are the new 8800 cards, you have to have a powerful CPU to keep the GPU's fed.

And having 2 cards does sort of mean better graphics because you are able to increase all/most of the visual settings in the games (this is what people usually call "eye candy")

And having 2 x 512MB cards doesn't exactly add up to 1GB. Each card can use it's own RAM, but they cannot share. So you couldn't have some super dooper ultra high quality large textures (that require more than 512MB) and expect it to work just because there is 2x512MB


SLI is a good option if you are big into FPS games (first person shooter) and need/want high FPS (frames per second). But if you don't have a higher resolution display, the second card isn't going to help much, if at all. (unless they are older cards and already struggle at the lower resolutions)

hope that helps a little bit?

 

[squashfx]

i would just like to add.... if your a benchmarker sli would help you

 

[pak]

Make sure the game you are playing takes advantage of it. I think most of the newer games do, especially FPS. WoW for one take 0 advantage to having a SLI set up.

--pak

 

[Zerix01]

Make sure the game you are playing takes advantage of it. I think most of the newer games do, especially FPS. WoW for one take 0 advantage to having a SLI set up.

--pak

Isn't SLI done on the driver level? Meaning even though WOW was never designed to run on SLI cards it would still use it's features because WOW is sending DX/OpenGL data to the driver which then would split the rendering data across the two cards. I guess you still wouldn't see much of a boost if you are using a newer card/s since the WOW engine is rather old now, but SLI still would work.

 

[JDawggS316]

Thank you all very much...The reason I ask is because I have a RAIDMAX RX630A 630watt PSU that doesn't support SLi for some reason; so I'm wondering if I ought to switch it out with one that does support SLi.

 

[ScottinIndy]

Have things changed with SLI? I haven't really followed it closely, I know the general rule was in the past that you got about a 30% increase in performance by adding the 2nd card, So to me it never seemed like a real cost effective/efficient option.
Also, If the O.P. is indeed considering SLI, You definelty don't want to trust that Raidmax PSU.

 

[Drew@PSU]

I would have to agree with Indy, that Raidmax sounds like bad mojo to me. Cruise on over to the Case and PSU forum for some better suggestions.
Anyway, SLI is a good bet for twitch style gaming as has been said. It helps keep the FPS floor higher, meaning even if you're running down the hall with all manner of nastiness going off around you, it won't turn into a slide show. I bought my first card on my initial build and grabbed the second after prices had dropped and games had gotten more system hoggish. It was worth it, if only for the "w00t, I have SLI! OMGWTFBBQ!" factor.

 

[jivetrky]

Have things changed with SLI? I haven't really followed it closely, I know the general rule was in the past that you got about a 30% increase in performance by adding the 2nd card, So to me it never seemed like a real cost effective/efficient option.
Also, If the O.P. is indeed considering SLI, You definelty don't want to trust that Raidmax PSU.

yeah, depending on the game the performance has gotten alot better than it first was. I thin the drivers help a lot with that also. When they made it all driver level, it helped a bit.

And I agree.....Raidmax and high performance do NOT go hand in hand. I wouldn't put any more money under the power of that PSU

 

[ScottinIndy]

yeah, depending on the game the performance has gotten alot better than it first was. I thin the drivers help a lot with that also. When they made it all driver level, it helped a bit.

And I agree.....Raidmax and high performance do NOT go hand in hand. I wouldn't put any more money under the power of that PSU

Thanks for the input, SLI/Crossfire is just something that I have never really considered to this point, I always figured with the cost, Power usage/need and heat I would rather just go with a single top end card if I needed it.
As far as the Raidmax PSU, I don't like to bash other peoples stuff, I just honestly wouldn't trust Raidmax to run any rig, Let alone a power hungry one. IMO the sooner he can change out the PSU the better.

 

[Dan0512]

And yes, two 512mb cards would make for 1gb of video ram.

No, no, no. When running SLI, each card has the exact same data on the memory. They can't share memory.

dan

 

[emceepecks]

No, no, no. When running SLI, each card has the exact same data on the memory. They can't share memory.

dan

My bad . I learn something new every day

 

[Alien1099]

Make sure the game you are playing takes advantage of it. I think most of the newer games do, especially FPS. WoW for one take 0 advantage to having a SLI set up.

--pak

I'm pretty sure you are wrong. SLI is handled by the OS/video drivers, not individual programs/games.

 

[Drew@PSU]

Some games have an SLI profile, in OEM parlance "taking advantage of SLI!" or "SLI Enabled!" or some such nonsense. SLI works, as Alien has stated, at the driver/frame buffer level. They can do it divided either horizontally or vertically, or by doing alternate frames. Its either AFR ( Alternate Frame Rendering ) or SFR ( Split Frame Rendering ). Crossfire I know nothing about, but then again we are in the nVidia section ( whew )

 

[pak]

I'm pretty sure you are wrong. SLI is handled by the OS/video drivers, not individual programs/games.

Well take a quick search in the WoW forums with "SLI." A lot of people have reported no gain from running WoW in SLI. Some have even reported a performance loss. I really don't understand SLI 100%. I just know it doesn't work with WoW so I care less about it. (For some reason, I still buy things for just in case I do want to run SLI. Go figure) I even tried it. I have a 7900GT and my son has a 7900GT. Both the exact same cards from EVGA. No gain. I also borrowed my friends 7950GX2. Nothing. And just to eliminate wow, I even tried Solitaire in SLI. No gain at all.

AFAIK, the game has to support SLI to take advantage of SLI. Someone correct me if I am wrong.

--pak

 

[sobe]

I hope you were joking about WoW and Solitaire....

SLi has a gain in quite a few games, however, when I SLi'd 2x 7900GTs, I didn't notice much of a difference at all in all honesty. In CounterStrike Source instead of 161FPS I would get around 178FPS average. Just not something I thought was worth it. I know that there is suppose to be some advantage towards SLi in future games and such, where 1 card will render and 1 card will basically determine physics like an Ageia PhysX card. But I don't have much knowledge into that.

I recommend just getting a single good card. The only other thing that I'd think that would help SLi would be rendering in AutoCad, 3D Studio Max, or other 3d modelling programs.

 

[LoneWolf121188]

There is/ a sticky on this...I know I haven't updated it in a while, but its still all correct.

In this section, I would also like to correct some rumors about SLI. The fist is people's belief that not all games can take advantage of SLI. This is simply not true. Unless you are running older games in which the CPU is the bottleneck and not the GPU, your games will run faster with SLI up to the point where the CPU becomes the bottleneck. A game does not have to be designed with SLI in mind to take advantage of it; in fact no game out right now was designed with SLI optimizations or anything, everything is done at the driver level. Saying a game won't run faster with SLI is like saying it won't run faster with a faster GPU, because that's essentially what SLI is: (almost) doubling the power of your GPU.

On a related note, if you see a minimal difference running SLI vs regular, there is something else SLI can do to help make games look better: SLI 8x or 16x antialiasing (AA). What this does is apply either a 4x AA pass or an 8x AA pass twice to each frame, one on each card, then combine the results to basically get 8x AA or 16x AA. Check out this page to see how it looks (sorry, I got a message saying I had posted too many images when I tried to have them actually in the thread), and for more info on SLI AA. SLI AA is enabled in CoolBits for now, but nVidia says they will make it a permanent part of the nVidia Control Panel in the next driver release.