anyone crossfire / sli?

[lex]

I'm thinking of picking up a second 4850 card on the cheap to crossfire in my system to give it a little performance boost, but I've been reading comments that crossfire (and sli) is just a big PITA.

Does anyone use a crossfire system?  Would you recommend it?

[Purge]

I do not, but I was thinking of doubling my 5770. Let me know how it goes.

[ibdoomed]

I'm thinking of picking up a second 4850 card on the cheap to crossfire in my system to give it a little performance boost, but I've been reading comments that crossfire (and sli) is just a big PITA.

Does anyone use a crossfire system?  Would you recommend it?

It used to be but not so much anymore assuming you're playing games made in the last couple years at the latest. With SLI sometimes you need to add a .exe to the profiles list in NvidiaInspector (even dead island needed this). There might be something similar with crossfire but I would do it in a heartbeat if I were ati.

[TheAtomicKid]

I wouldn't do it in preference to skipping two generations of gpu's, and bout to be three. New AMD cards in november timeframe. Hold man, HOLD!

http://www.techpowerup.com/153681/AMD-s-First-28-nm-GPUs-in-December.html

Atomic

[lex]

Yeah, I've been debating whether it's worth it or not, or just buy a new card.  I want to be able to keep my current PC for another year or two before getting a new one.

Most games play fine on 1600x900, but some of the newer ones I have to turn down the options for in 1900x1080.

It's not an urgent upgrade, so I'll wait and see what new cards they come out with and maybe there'll be a price drop on the current ones.

[Ridah]

I'm about to put a second 6950 into my system.

Anything I need to know going into this? Do I just put the second card in, connect the bridge, and I'm good to go?

[IamChuckles]

I ran a Crossfire 4850 system for about a year.  I do not recall having any significant issues.  I would recommend only using 1 GB 4850 cards.  I will say that some games had better performance than others.  I upgraded to a 5850 and I honestly cannot tell much of a difference.  I guess it is a bit more quiet.

[Ridah]

Should I have my video card drivers installed to the same HD as my games?

[TheAtomicKid]

No, there's only one place to install them, and that's to the system drive. They end up in places like /windows/system and elsewhere.

Atomic

[Ridah]

Actually I went ahead and put them in the same drive as my games and things seem to be working fine, I noticed a difference in the installation of the drivers where I was prompted to accept something being installed to the HD. That prompt doesn't usually come up.

[Ridah]

I need a PSU with four PCI Express: 6-pin connectors right?

[CeeKay]

I need a PSU with four PCI Express: 6-pin connectors right?

Yep, that what my dual 5870's needed.  Sometimes the cards will include cables to convert the 6 pin into a 4 pin; I may have that backwards and it could be the other way, I'm not at home to check.

[Ridah]

What do you have now?

[CeeKay]

What do you have now?

got tired of microstuttering so I'm just with a single GTX 580 now.  it's funny, my benchmarks are worse but game performance is way better.

It's also a lot cooler, and my PC is much quieter as a result.

[edit] 6950's might not experience micro stuttering IIRC.

[Ridah]

I guess I'll see how it goes and if there's a problem I'll return the second 6850 and sell the original one. I'm hoping there's no issues though because the framerates I should achieve from 6850 CF look phenomenal.

[CeeKay]

here's an article on the microstuttering I meant to link to:  http://www.tomshardware.com/reviews/radeon-geforce-stutter-crossfire,2995.html

here is the part about the 6950's being OK (of course you've mentioned 6850's also):

CrossFire With Two Cards

If you're only judging based on average frame rates, two cards seems like a great deal for the price. We've had several readers write in, though, complaining about this micro-stuttering issue, which simply cannot be seen in the context of normal benchmarks.

Even at frame rates above 50 FPS, micro-stuttering rears its ugly head, pronounced enough to significantly detract from the gaming experience. A paradigm shift seems necessary, at least until both AMD and Nvidia are able to prevent or mask the artifact. Right now, if you asked us whether it'd be smart to "go cheap" on an inexpensive card and double-down later with another one, we'd have to suggest against it if you're the sort to be bothered by micro-stuttering. The improvement in performance would be negated by the phenomenon's impact. Currently, it seems like cards less powerful than the Radeon HD 6950 are not well-suited for dual-card CrossFire. Even if the frame rates look decent, the slower the GPU, the more pronounced you'll see micro-stuttering during gameplay.

At the same time, not everyone is equally sensitive to time-skewed frame sequences, and quite a few cheap TFT LCD displays help hide the effect. Even so, AMD has a major undertaking ahead of it in order to really improve the dual-card experience.

as mentioned in there it's something you might not even notice.  personally it always felt something was off with my setup, and it became noticeable after a while in Witcher 2 so I retired them to my backup rig.

[Ridah]

I have two 6950s, sorry for the confusion.

I'm pretty anal about hiccups and framerate issues, I'm always bitching about framerates on console games. I'll test my crossfire setup and report back.

[Ridah]

Installed the hardware, played Dead Space 2 for about 20 minutes and everything seemed peachy. No micro-stuttering far as I could tell.

So excited for this Battlefield 3 download to complete 

Negative side-effect: My computer sounds like a mini vacuum now. Kinda not digging it, hoping I get used to it. Maybe I'll just look for an alternative, more quiet PSU.

One thing I don't get is why so many PSUs are listed as "crossfire ready" when they only have 2x PSI-E connectors. You need two for EACH, don't you? Unless it's counting lower-end video cards that only need one each.

[Thin_J]

I had some micro-stuttering in certain games with my dual GTX460's in SLI before.

I have none in any game that I've played to date with my Crossfired 2GB 6950's.

[TheAtomicKid]

Thankyou for the link, Ceekay, that's quite the interesting read. Got me thinking about my next set of upgrades, which I'd already been thinking about lately.

Sandy Bridge E coming soon. AMD gpu's coming soon. Decisions, decisions.

Atomic

PS: It would seem the trick to avoiding microstuttering, is to make sure your settings keep your minimum framerate as far north of 30fps as you can stand, visually. Since 30fps seems to be the zone where it becomes noticeable enough to be a problem. The bigger your cards, the higher those settings can be, naturally.

[CeeKay]

Thankyou for the link, Ceekay, that's quite the interesting read. Got me thinking about my next set of upgrades, which I'd already been thinking about lately.

Sandy Bridge E coming soon. AMD gpu's coming soon. Decisions, decisions.

no problem.  I hear AMD's GPU's are supposed to be out early to mid-December, but with a very limtied quantity; basically it sounds like it will be done that way just so they can say 'we got them out in 2011'.