For some reason I feel like everyone has bought into a miss-conception.

[Jack.EXE]

Alright, we all know Crossfire and SLI suffer from stutter, or at least they did.

 

However, while 2 way has always had this issue, 3 way has been flawless since day one.

 

A common solution back when the 6970 was a thing was to buy a third card if the two were stuttering.

 

you see, when you run 3 way cards, an odd phenomenon occurs. No matter how many GPUs were in the system, an odd number does not suffer from stuttering.

 

Tom's Hardware conducted a study in 2011 about how GPUs behave in multi-card situations, using 3x 6870s for this specific test:

 

 

We repeated this same test using a number of games yielding different average frame rates. So long as the average is above 30 FPS, the resulting output is almost stutter-free. Minor differences in when frames hit the screen are not apparent, and so they don't bother us at all. The experience is similar to using a single GPU.

After analyzing the dual-card configuration, this is certainly not what we were expecting.

 

The point is, people all too often overlook this phenomenon, which is all too useful for higher end configs.

 

Tom's Hardware Article:

http://www.tomshardware.com/reviews/radeon-geforce-stutter-crossfire,2995.html

 

Alright, so the science behind this is actually in the way the drivers handle the multi-gpu configs.

In a two or four way config, the drivers assign each card its own frame, each taking a turn to render. the issue here is that if one GPU lags behind the other(s), it will cause micro-stutter.

in a three way GPU config, the drivers actually cant make sense of the 3rd card, it doesn't know how to incorporate it into a turn system, so it results in the 3 cards being treated as one, large, GPU, each contributing pixels to the picture as fast as they can, in no specific order.

[Jobbe03]

Probably just AMD drivers being shitty as usual... ;P

[flibberdipper]

And it looks nicer.

[Jack.EXE]

Probably just AMD drivers being shitty as usual... ;P

 

Uhm, explain this reasoning?

 

This occured with both Nvidia GPUs and AMD gpus, back in 2012 and earlier, both cards stuttered in dual card configs, yet were perfectly fine in 3 way.

[Jobbe03]

Uhm, explain this reasoning?

 

This occured with both Nvidia GPUs and AMD gpus, back in 2012 and earlier, both cards stuttered in dual card configs, yet were perfectly fine in 3 way.

I was just kidding, i know both brands have had issues with this. AMD's drivers are just notoriously bad

[Kyuubixchidori]

so, the solution is to throw money at the problem?

 

hard to justify to signifigant other that buying ANOTHER graphics card wont add performance in most situations, and in some cases hurt it, but still helps lol

[othertomperson]

I suppose the real question is whether it is worth buying a whole new card (a new fantastic GPU) just to stop stuttering in a really minuscule number of games when the performance scaling really isn't fantastic. If it scaled well across the board AND established always consistent frame times then it would make more sense.

[Jack.EXE]

updated OP with the reason for this insanity.

[Dive5885]

Alright, we all know Crossfire and SLI suffer from stutter, or at least they did.

 

However, while 2 way has always had this issue, 3 way has been flawless since day one.

 

A common solution back when the 6970 was a thing was to buy a third card if the two were stuttering.

 

you see, when you run 3 way cards, an odd phenomenon occurs. No matter how many GPUs were in the system, an odd number does not suffer from stuttering.

 

Tom's Hardware conducted a study in 2011 about how GPUs behave in multi-card situations, using 3x 6870s for this specific test:

 

The point is, people all too often overlook this phenomenon, which is all too useful for higher end configs.

 

Tom's Hardware Article:

http://www.tomshardware.com/reviews/radeon-geforce-stutter-crossfire,2995.html

 

Bear with me while I get the science behind the phenomenon.

I had a 3-way setup and it was worse than 2-way..

 

But I'm sure its because I play on a 1080p display.

[Jack.EXE]

I had a 3-way setup and it was worse than 2-way..

 

But I'm sure its because I play on a 1080p display.

 

Which cards?

[Tacitus]

But two-way SLI/CFX suffers less from issues of negative scaling, and in some cases, lower minimum framerates.

 

As far as I know microstutter is a non-issue today anyway, but that was an interesting read.

 

I wonder if they could implement the technique which accidentally solved 3way solutions to two and four cards.

[Dive5885]

Which cards?

Reference 7950's

[Adreyu]

3 way sli motherboards are so expensive though

[BurgerBum]

I was just kidding, i know both brands have had issues with this. AMD's drivers are just notoriously bad

not the most recent one.... its working pretty damn well.

3 way sli motherboards are so expensive though

i dunno.. the M5A99FX PRO R2.0 from asus isnt that bad... only 110.

[BurgerBum]

But two-way SLI/CFX suffers less from issues of negative scaling, and in some cases, lower minimum framerates.

 

As far as I know microstutter is a non-issue today anyway, but that was an interesting read.

 

I wonder if they could implement the technique which accidentally solved 3way solutions to two and four cards.

oh it is definately a thing nowadays. 

[Briggsy]

Both Nvidia and AMD drivers were balls-awful until a few years ago. I know for AMD at least you can assign AFR (alternate frame rendering) to assign each card to its own frame or even 1x1 AFR for severe compatibility issues, but regular crossfire and SLI do not work like this normally unless you manually set CF/SLI to AFR mode, which sucks. in a 3 monitor setup, I can see 2 cards causing all kinds of issues.

[Najuno]

oh it is definately a thing nowadays. 

I am very sensitive to micro stuttering and I can only tell you this I can´t see it anymore with my GTX980 2 way SLI. I recently built a rig with a GTX970 2way SLI and same, no MS at all. Maxwell and the nVidia drivers are working perfectly fine as far as I can tell.

[BurgerBum]

I am very sensitive to micro stuttering and I can only tell you this I can´t see it anymore with my GTX980 2 way SLI. I recently built a rig with a GTX970 2way SLI and same, no MS at all. Maxwell and the nVidia drivers are working perfectly fine as far as I can tell.

well, the whole ''nowadays'' was very general.

with th newest tech no, however im sure it might happen eventually with certian issues.

with tech that is still valid today yes. (270, some APUs, yaddah yaddah)

[Najuno]

well, the whole ''nowadays'' was very general.

with th newest tech no, however im sure it might happen eventually with certian issues.

with tech that is still valid today yes. (270, some APUs, yaddah yaddah)

Oh I´ve seen other scenarios with cards like the 7990... that micro stuttering was driving me almost insane, and same with nVidia cards in the past. But lately AMD and nVidia seem to optimize their drivers better.

[MattLantis]

That was also almost 4 years ago at this point

[BurgerBum]

Oh I´ve other scenarios with cards like the 7990... that micro stuttering was driving me almost insane, and same with nVidia cards in the past. But lately AMD and nVidia seem to optimize their drivers better.

yup.

 

 

 

it aint microstutter. its full on all 30 of my 42 fps in TF2 are being displayeed in the first 1/6 of the second, and the last frame is just kept there. 

annoying as hell. smooth STAHP.............. smoooooooooo as baby butt STAHP................. smooooooooooooooooo DIE IN A HOLE

[hiyayhi]

Probably just AMD drivers being shitty as usual... ;P

I seriously hope you are just a troll, This occurs in BOTH AMD and Nvidia dual GPU configs, so it may be badly designed drivers, but i would be badly designed drivers on both AMD and Nvidia's part.

 

I see a serious problem in designing the drivers like this, When you have a dual GPU setup, sure they are supposed to be the same card and output the same performance, but when you put two cards into SLI / CrossfireX next to each other, the top card gets significantly hotter, basically creating a bottleneck for the top card, it may not seem like much but it could be enough to create this kind of stutter. That is not even considering the amount of variation from card to card due to the manufacturing process.

 

Anyway, I find this quite interesting and I am going to give this a shot, I have a 6990 that is still going strong, I can probably find a 6970 for not too much, and report back my experience.

[hiyayhi]

I am very sensitive to micro stuttering and I can only tell you this I can´t see it anymore with my GTX980 2 way SLI. I recently built a rig with a GTX970 2way SLI and same, no MS at all. Maxwell and the nVidia drivers are working perfectly fine as far as I can tell.

This is completely accurate, the newest of both AMD and Nvidia have improved the frame stutter issue immensely.

The 290 / x fixes it by somehow making the CrossfireX do voodoo magic shit through the Pcie bus, and the Maxwell GPU's have some sort of actual physical hardware thing with them to improve it.

You just need to go back to 280x / 7970, or 770 / 680, to find microstutter.

So, technically the newest parts have fixed the problem, but people are still buying the older hardware and it isn't fixed in that. Leading me to believe it is more of a hardware problem than a software problem, although I am very aware that the software plays a big part in it.