Sli and Crossfire questions

[ImThatFluffy]

What is the improvement in a Sli or crossfire configuration. 

[Samfisher]

Anywhere between 50-95% boost depending on drivers and game.

[xBlizzDevious]

Well both technologies are designed to allow multiple GPUs to work in tandem to produce more juicy frames every second. In a lot of games, it doesn't work. In a lot of cases, you'll get microstutter and sometimes, you'll even get lower performance. It'll also increase power costs and heat output significantly.

 

Now, if you're still interested, it does work - sometimes. In games that are optimised for it, Battlefield 3 is the example I shall use, I can get well over 60FPS on ultra at 3 x 1080P with three 7970s. A single one will get 25-50 on the same settings. But in other games, I'll use Euro Truck Simulator 2, I get almost exactly the same framerate whichever I use. Though I will sometimes get a little bit of microstutter which takes away from the experience.

 

Certainly with AMD (I'm not sure about Nvidia, but I've heard that their SLI support is better than AMD's Crossfire), you can enable and disable crossfire per executable as well as many other settings which can increase and decrease performance.

[ImThatFluffy]

Well both technologies are designed to allow multiple GPUs to work in tandem to produce more juicy frames every second. In a lot of games, it doesn't work. In a lot of cases, you'll get microstutter and sometimes, you'll even get lower performance. It'll also increase power costs and heat output significantly.

 

Now, if you're still interested, it does work - sometimes. In games that are optimised for it, Battlefield 3 is the example I shall use, I can get well over 60FPS on ultra at 3 x 1080P with three 7970s. A single one will get 25-50 on the same settings. But in other games, I'll use Euro Truck Simulator 2, I get almost exactly the same framerate whichever I use. Though I will sometimes get a little bit of microstutter which takes away from the experience.

 

Certainly with AMD (I'm not sure about Nvidia, but I've heard that their SLI support is better than AMD's Crossfire), you can enable and disable crossfire per executable as well as many other settings which can increase and decrease performance.

so i can turn off crossfire for a game like Euro truck simulator 2 and then turn it on for battlefield 3

[i_build_nanosuits]

Anywhere between 50-95% boost depending on drivers and game.

0% to 80% would be more accurate...many games at realease wont support dual gpu's until they release a profile for it...50% to 65% is where most games end up.

[xBlizzDevious]

so i can turn off crossfire for a game like Euro truck simulator 2 and then turn it on for battlefield 3

 

Yes. Unfortunately, you'll probably have it set to turn off for a lot of games, especially if you don't play big games that are marketed as very graphically intensive.

 

Don't quote me on this - as it doesn't really require it - but I think that Call of Duty is an exception to that and does work with Crossfire/SLI quite well even though it's not particularly intensive.

[Tacitus]

0% to 80% would be more accurate...many games at realease wont support dual gpu's until they release a profile for it...50% to 65% is where most games end up.

 

0-95% is probably more accurate yet. I'd say that in the period between the r9 290 launch and now 75% scaling is probably the average a pair of those cards would see in AAA games also launched in that period.

[Najuno]

Well both technologies are designed to allow multiple GPUs to work in tandem to produce more juicy frames every second. In a lot of games, it doesn't work. In a lot of cases, you'll get microstutter and sometimes, you'll even get lower performance. It'll also increase power costs and heat output significantly.

 

Now, if you're still interested, it does work - sometimes. In games that are optimised for it, Battlefield 3 is the example I shall use, I can get well over 60FPS on ultra at 3 x 1080P with three 7970s. A single one will get 25-50 on the same settings. But in other games, I'll use Euro Truck Simulator 2, I get almost exactly the same framerate whichever I use. Though I will sometimes get a little bit of microstutter which takes away from the experience.

 

Certainly with AMD (I'm not sure about Nvidia, but I've heard that their SLI support is better than AMD's Crossfire), you can enable and disable crossfire per executable as well as many other settings which can increase and decrease performance.

 

IDK about the latest cards of AMD in Crossfire. But until recently I was running a GTX780Ti 2way SLI with a 1440p IPS monitor. I am super sensitive to micro stuttering and all I can tell you neither my old config with the 780 Ti s nor the new 2way GTX980 SLI cause a lot micro stuttering.

True I can see it here and there, but what really helps, if you run your cards linked.

SLI profiles are available for many games and even if it´s not 100% optimized you can still benefit from it. Except for the higher power withdraw I do not see many downsides. In fact it is always good to have more GPU horse power when you move away from 1080p.

 

My GTX980 2way SLI has a max Watts withdraw of 550Watts total. That with an i7 5930K with a TDP of 140Watts isn´t too bad.

[FreezeFlyte]

Unless you are going to run intensive graphic games across multiple monitors then you are better off just saving and getting a more powerful single card. CrossfireX and SLI are great technology if you are going to use them to their full potential. But if you are only going to game on a single 1080p monitor then a single gpu is much better.

[xBlizzDevious]

IDK about the latest cards of AMD in Crossfire. But until recently I was running a GTX780Ti 2way SLI with a 1440p IPS monitor. I am super sensitive to micro stuttering and all I can tell you neither my old config with the 780 Ti s nor the new 2way GTX980 SLI cause a lot micro stuttering.

True I can see it here and there, but what really helps, if you run your cards linked.

SLI profiles are available for many games and even if it´s not 100% optimized you can still benefit from it. Except for the higher power withdraw I do not see many downsides. In fact it is always good to have more GPU horse power when you move away from 1080p.

 

My GTX980 2way SLI has a max Watts withdraw of 550Watts total. That with an i7 5930K with a TDP of 140Watts isn´t too bad.

 

I'm quoting the "if you run your cards linked" bit, specifically. What do you mean by that?

 

I too am rather sensitive to micro-stutter and that's why I splashed out on three 7970s instead of "just" two - also because I'm running three 1080P monitors and not just one. The reasoning behind that is that one card has very little micro-stutter, two cards have a lot, three cards have a little bit more than single and quad goes is somewhere between two and three. Or at least, that's what I found out from a lot of research online.

Anyways, what exactly do you mean by "linked"?

 

 

Unless you are going to run intensive graphic games across multiple monitors then you are better off just saving and getting a more powerful single card. CrossfireX and SLI are great technology if you are going to use them to their full potential. But if you are only going to game on a single 1080p monitor then a single gpu is much better.

 

I kinda have to agree with you here. Certainly on a single 1080P screen, almost nothing will stump a 7970 which is now nearly 3 years old. So good luck finding something that will stump a 980. At 1440P, maybe. Anything more and probably yes. Haha.

[Samfisher]

0% to 80% would be more accurate...many games at realease wont support dual gpu's until they release a profile for it...50% to 65% is where most games end up.

 

That's a hideously low scaling number.  The real numbers for most bigger games range from 60-95%  For smaller lesser known games, probably less.

[CatCloud]

Yes. Unfortunately, you'll probably have it set to turn off for a lot of games, especially if you don't play big games that are marketed ed as very graphically

Eeehy aside from star citizen I've never had to turn off SLI for a game to work, do name some games and I'll try them, but I'm damn sure most games have no issues with SLI.

It could be a AMD/crossfire issue though.

Anyway give me list of games and I'll try those I've got.

[xBlizzDevious]

Eeehy aside from star citizen I've never had to turn off SLI for a game to work, do name some games and I'll try them, but I'm damn sure most games have no issues with SLI.

It could be a AMD/crossfire issue though.

Anyway give me list of games and I'll try those I've got.

 

I'm not saying that certain games have severe issues that make them not work at all, just that there's no benefit to using three times the electricity to get no performance boost.

 

Also note that I have recently switched a load of stuff around, have updated to the latest beta drivers and have also gone from using two mini DisplayPort and a DVI connector on my Eyefinity setup to using a DisplayPort splitter so that all of the Eyefinity screens run off of that same port. This seems to have changed the way a few things work- Just Cause 2, for example, seems to use Crossfire quite well now. Also note that Eyefinity could be causing some issues of its own too.

 

Games I find that I have no benefit from (and that I can think of just now) include:

Indie games:

- Heavily modded Minecraft in particular (this one is probably more CPU bound though).

- Space Engineers.

- Kerbal Space Program (this one is also probably more CPU bound. A 4.4GHz 3930k just gets stumped by it).

- Euro Truck Simulator 2.

Other games:

- Anno 2070.

- Test Drive Unlimited 2.

- HAWKEN (though I haven't played that for a while and don't care for it).

- TERA.

- Dragon Age 2 (didn't have three GPUs when I played the first one, but probably that one too).

- Skyrim gets some performance boost (or at least it did a few months ago, but not much - not tried since above changes)

- Tomb Raider was the worst for micro-stutter. I'd be getting a great framerate, but if I switched on TressFX, it'd stay above 60FPS 90% of the time, but almost always feel like 20-30FPS. Again, not tried since above changes.

 

That's all of the ones I can think of just now, but I reformatted very recently too and have lost all of my CCC profiles.

[Najuno]

I'm quoting the "if you run your cards linked" bit, specifically. What do you mean by that?

 

I too am rather sensitive to micro-stutter and that's why I splashed out on three 7970s instead of "just" two - also because I'm running three 1080P monitors and not just one. The reasoning behind that is that one card has very little micro-stutter, two cards have a lot, three cards have a little bit more than single and quad goes is somewhere between two and three. Or at least, that's what I found out from a lot of research online.

Anyways, what exactly do you mean by "linked"?

 

 

 

I kinda have to agree with you here. Certainly on a single 1080P screen, almost nothing will stump a 7970 which is now nearly 3 years old. So good luck finding something that will stump a 980. At 1440P, maybe. Anything more and probably yes. Haha.

 

nVidia gives you the option with an SLI to either run your SLI with every card tuned in individually clock speed, ram speed temp power overall all adjustments or to link the cards, in this case all cards run the same setup. The benefit at least for nVidia cards is (tested this myself) that you have a cleaner overlay rather than an overlap of pictures. Sure like written before I still see some micro stuttering a bit, but when I run both cards, let´s say for hard OCed benchmarks, with individual settings the micro stuttering gets a lot more present.

 

The problem is with CF or SLI it always depends how sensitive a person is. I can see and feel that right away, but a friend of mine was running a 7990 for a good long while and whilst this card freaked me out he nerver even felt anything wrong with it. The best way to see if SLI or CF is an option for somebody, aside from costs or more power withdraw, is to see that with another person´s setup and decide then from there on.

 

Same with resolutions for monitors. Some people run 27" 1080p TN displays and are super happy with it. I prefer much high res than that but then again some of my friends didn´t even realize they were sitting in front of more that 1080p when the sat in front of my pc.