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Does crossfire really work

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November 27, 2011 6:48:19 AM

Is SLI and Crossfire a gimmick or do they give twice the graphics power of a single card? Are two R6950 1GB cards in crossfire better then a single R6950 2GB card?

More about : crossfire work

November 27, 2011 7:00:16 AM

it usually give about a 90% performance increase. 2 definitely
November 27, 2011 7:52:26 AM

CrossFire does not double performance. The boost is approx. 30%, maybe more in some cases, which is somewhat significant. Two HD 6950 1GB will perform better than a single 2GB HD 6950. The extra VRAM in the 2GB version does help in high resolutions and demanding games, not to mention lessening the chance of memory leakage.
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November 27, 2011 7:56:52 AM

well i have read that actually opposite is true, that if you could you should avoid xfire
November 27, 2011 7:58:01 AM

AbdullahG said:
CrossFire does not double performance. The boost is approx. 30%, maybe more in some cases, which is somewhat significant. Two HD 6950 1GB will perform better than a single 2GB HD 6950. The extra VRAM in the 2GB version does help in high resolutions and demanding games, not to mention lessening the chance of memory leakage.


what do you mean y memory leakage?
November 27, 2011 8:11:06 AM

The only issue relevant to XFire are drivers. Some people run into issues, others don't. It's luck, really. Nvidia's SLI drivers don't really have any issues. I am not sure where you read up that XFire is bad, but wherever it was from doesn't know what they are talking about.

Memory leakage can occur in different forms. The one I am talking about is in graphic cards. If the memory on the graphics card runs out, but the program needs more, it will use system memory, which is the RAM. The program could slow down significantly.
November 27, 2011 9:11:55 AM

So we have one guy who says 30%, and another who says 90%. I believe on avg its closer to 75-80%. There are some games however where it doesn't work at all (GTA4, Skyrim) or poorly. (WoW.)

Two cards should always be faster then an exact same card with more RAM. There are very few cases where you need more then 1GB of Vram. Just being a 2GB 6950 won't make it faster then a 1GB. As a matter of face I believe when the 1GB cards came out they are ever so slightly faster then the 2GBs because they could use tighter timings.
November 27, 2011 9:21:08 AM

The one downside of crossfire is that there are lots of incompatibilities with games and drivers almost always have to be updated with new releases.

I've been crossfiring two 4850s for about 2 years and I will never crossfire cards again.
November 27, 2011 2:41:00 PM

AbdullahG said:
The only issue relevant to XFire are drivers. Some people run into issues, others don't. It's luck, really. Nvidia's SLI drivers don't really have any issues. I am not sure where you read up that XFire is bad, but wherever it was from doesn't know what they are talking about.

Memory leakage can occur in different forms. The one I am talking about is in graphic cards. If the memory on the graphics card runs out, but the program needs more, it will use system memory, which is the RAM. The program could slow down significantly.


I've spent years trying to build a system to run FSX. My current build comes close to running it stutter free.
My system: AMD PHENOM II 6 CORE PROCESSOR
MSI GAMING SERIES SOCKET AM3 MOTHERBOARD
CRUCIAL 128 GB SOLID STATE DRIVE SATA 6GB/S 2.5
MSI RADION R6950 2GB GDDR5 PCI EXPRESS 2.1 TWIN FROZR II OC
600watt PSU

I'm going to upgrade to a 1000 watt PSU, and am thinking about adding another 2GB Twin Frozr II, or should I just upgrade to a 6990 2 GB card, or go back to nVidia SLI?
November 27, 2011 2:51:24 PM

It really depends on the game. Now I've got crossfire working on Battlefield 3 I get almost double the frame rate, the same for DiRT 3 now. Even gAmes that aren't officially supported usually work fine. Anyone saying that crossfire doesn't support many games needs to check their head because pretty much all games work well now. Just don't get cheapo motherboards and power supplies and crossfire and sli should work great. For the most part I'd say crossfire yields better scaling than SLI according to the benchmarks I've seen on this site.
November 27, 2011 2:55:41 PM

AbdullahG said:
CrossFire does not double performance. The boost is approx. 30%, maybe more in some cases, which is somewhat significant. Two HD 6950 1GB will perform better than a single 2GB HD 6950. The extra VRAM in the 2GB version does help in high resolutions and demanding games, not to mention lessening the chance of memory leakage.


Umm it's definitely more than 30%.
November 27, 2011 2:57:02 PM

4745454b said:
So we have one guy who says 30%, and another who says 90%. I believe on avg its closer to 75-80%. There are some games however where it doesn't work at all (GTA4, Skyrim) or poorly. (WoW.)


+1
November 27, 2011 3:06:22 PM

bushrat2 said:
Is SLI and Crossfire a gimmick or do they give twice the graphics power of a single card? Are two R6950 1GB cards in crossfire better then a single R6950 2GB card?

Try reading the articles that sport crossfire setups and see for yourself if it is true or not. Though the percentage of improvement would vary depending on the game compatibility, driver support, etc.

2 x 6950s 1GB > 1 x 6950 2GB

Unless you forgot to install the crossfire bridge..
November 27, 2011 3:21:12 PM

bushrat2 said:
I've spent years trying to build a system to run FSX. My current build comes close to running it stutter free.
My system: AMD PHENOM II 6 CORE PROCESSOR
MSI GAMING SERIES SOCKET AM3 MOTHERBOARD
CRUCIAL 128 GB SOLID STATE DRIVE SATA 6GB/S 2.5
MSI RADION R6950 2GB GDDR5 PCI EXPRESS 2.1 TWIN FROZR II OC
600watt PSU

I'm going to upgrade to a 1000 watt PSU, and am thinking about adding another 2GB Twin Frozr II, or should I just upgrade to a 6990 2 GB card, or go back to nVidia SLI?


FSX has never benefited at all from crossfire/SLI. It is more CPU intensive than anything, the biggest upgrade you could make for that game would be either overclocking your CPU or upgrading to an I7 build.

Here is an article on crossfire/SLI scaling in other games:

http://www.tomshardware.co.uk/crossfire-sli-3-way-scali...
November 27, 2011 3:58:31 PM

I can't comment on Xfire but I have 2 GTX 580's in SLI and the frame rate is close to double in any games I have played compared to just the single 580. That includes WoW, one of the games mentioned above as not working well. I think what that person was experiencing was a CPU bottleneck, I don't have that problem on my 2600k machine. Going from single to SLI 580 gives roughly double the frames for me.

There are a few extremely poorly coded games out there that seem to not really benefit from it but that is more a problem with it being a shoddily produced game more than anything. This is however why for example one GTX 580 is recommended over 2 lower end cards in SLI that would give similar performance to the single 580, because sometimes the 2nd card isn't being used right by the shoddy game software. That is why it is usually recommended only to SLI higher end graphics cards.
November 27, 2011 4:14:52 PM

Hi

I have an I7 2600K CPU, OC yo 4.4 GHZ. 1200W PSU and had 2 X HD6990 running in quad fire. I recently had to replace a faulty Asrock extreme 4 Mobo and upgraded to the Extreme 7 board as i thought id get a slight performance increase. The PCIe slots allow the 2 cards to run at x16, wheras the extreme 4 board was X16 and X8 for the second card.

I have had to actually remove 1 of the GPU's to run Sky rim as with the 2 in i cant even play the game due to stupid FPS <30. If i try disabling the 2nd card in CCC i just get BSOD and have to physically remove the 2nd card.

Basically im not impressed at all with the quadfire/crossfire at all. Some games run really well but more run poorly than better. Its stupid that i have to have a £600 GPU sat next to the PC as it runs better with the 1 for some games.

I dont think id try the same type of set up again, the hardware seem really good but the driver support from ATI really is shocking. Stay away from multi cards if possibel. Well thats my experiance anyway.
November 27, 2011 4:22:30 PM

davexxsmith said:
Hi

I have an I7 2600K CPU, OC yo 4.4 GHZ. 1200W PSU and had 2 X HD6990 running in quad fire. I recently had to replace a faulty Asrock extreme 4 Mobo and upgraded to the Extreme 7 board as i thought id get a slight performance increase. The PCIe slots allow the 2 cards to run at x16, wheras the extreme 4 board was X16 and X8 for the second card.

I have had to actually remove 1 of the GPU's to run Sky rim as with the 2 in i cant even play the game due to stupid FPS <30. If i try disabling the 2nd card in CCC i just get BSOD and have to physically remove the 2nd card.

Basically im not impressed at all with the quadfire/crossfire at all. Some games run really well but more run poorly than better. Its stupid that i have to have a £600 GPU sat next to the PC as it runs better with the 1 for some games.

I dont think id try the same type of set up again, the hardware seem really good but the driver support from ATI really is shocking. Stay away from multi cards if possibel. Well thats my experiance anyway.



I believe crossfire may actually have some serious issues compared to SLI, it is possibly just driver related but it is definitely having issues. Check out this article on BF3 where SLI and Xfire were compared using high end cards. http://hardocp.com/article/2011/11/22/battlefield_3_mul...

Just a snip...
Quote:

Throughout all of our testing it was apparent that the NVIDIA GPU based video cards were providing better performance and more enjoyable gameplay than the AMD GPU based video cards. There were no instances that we found where any AMD card provided better gameplay performance than it's NVIDIA counterpart. We also experienced an issue which we believe to be driver related with all AMD video cards. We experienced an extremely noticeable lag any time there was a large amount of debris flying around, explosions from missiles, grenades or vehicles, or buildings in the environment being destroyed. This was not present on any of the NV based GPUs.

The NVIDIA GeForce GTX 580 SLI and AMD Radeon HD 6970 CFX were both able to play Battlefield 3 Multiplayer at 2560x1600 with FXAA High, 16X AF, and all Ultra in-game graphics options with HBAO selected. They performed 12-16 average FPS above our 60 average FPS goal with maxed settings and were both enjoyable. In the Apples-to-Apples tests the AMD Radeon HD 6970 CFX had a 1 FPS advantage but the lag during explosions was much more evident than during highest playable settings testing, thus providing a worse gameplay experience.

The NVIDIA GeForce GTX 580 and AMD Radeon HD 6970 both performed within .2 FPS of each other at 1920x1200 with 16X AF, FXAA High and all Ultra in-game settings including HBAO. The NVIDIA GeForce GTX 580's performance was favorable without the lag that all AMD cards experienced.


Anonymous
November 27, 2011 4:27:22 PM

It's been said before, but if possible just stick to one high end card. Running 2 cards in scaling (CFX or SLI) you will almost always have problems. You will also see some micro-stuttering and run into driver issues or games that don't support it well enough to justify the costs. Having tried both SLI and CFX I can say that personally SLI was a better experience and more games are optimized for that architecture (if you must go for multiple cards.) Just my 2 cents.
November 27, 2011 4:31:03 PM

Quote:
It's been said before, but if possible just stick to one high end card. Running 2 cards in scaling (CFX or SLI) you will almost always have problems. You will also see some micro-stuttering and run into driver issues or games that don't support it well enough to justify the costs. Having tried both SLI and CFX I can say that personally SLI was a better experience and more games are optimized for that architecture (if you must go for multiple cards.) Just my 2 cents.



I still haven't seen any micro-stuttering on my machine yet. My eyes are pretty sensitive to those things, and I have seen youtube videos of it but I have yet to ever experience it on my machine. Though I have read that it isn't present on high end Nvidia GPU's. I've yet to have any issues at all with my SLI setup, but I am aware that some people do have issues, but I have not.
November 27, 2011 4:42:12 PM

The problem does seem to me to be the driver support from AMD. Nvidia do get the updated drivers released quicker normally. The update driver came out yesterday for sky rim but didnt imporve things enough with the 1 card in so it really wasnt worth fitting the 2nd card back in the system.
The micro stuttering is bad on this game with the 6990's and on the net it says if you play in windowed mode its better and it is. That aslso screws up the Xfire as it dosent work in windowed mode i belive.
Im really tempted to sell 1 6990 but then do i try Nvidia 580, 590 or am i just going to end up with the same problems. Oh the joy of messing around with computers.
I actually got lower benchmark scores when i upgraded the mobo to run both cards at X16. I mailed Asrock but didnt even get a reply. I should have got a 1 to 2% increase but i got about 200 lower score in Heaven 2.5??
November 27, 2011 4:56:44 PM

Lots of opinions here, so I'll give mine as I have ran Crossfire and SLI both for quite a few years. Does Crossfire work? Yes it does. How well it works depends on many variables, mostly how the game is optimized. Sometimes it won't help at all, sometimes your frame rates may double. I think that overall, SLI performs better.
I have never encountered any of the "problems" you hear about, every Crossfire or SLI setup I have ever ran, well quite frankly ran quite well. Makes me wonder about the configuration and settings, and what ever else people are doing to their PC's that cause them to have so many problems with multiple cards.
November 27, 2011 4:59:30 PM

davexxsmith said:

Im really tempted to sell 1 6990 but then do i try Nvidia 580, 590 or am i just going to end up with the same problems. Oh the joy of messing around with computers.
I actually got lower benchmark scores when i upgraded the mobo to run both cards at X16. I mailed Asrock but didnt even get a reply. I should have got a 1 to 2% increase but i got about 200 lower score in Heaven 2.5??



I have nothing but good things to say about the 580's in SLI. It provides me with smooth game play on every game I have run on them @2560x1440 and max settings. It also provides more rendering power than a GTX 590 by almost 30%. It's your wallet and no matter what you decide to do (other than just keeping what you have) it will cost you a good chunk of $$.

There are a few poorly coded or new and still buggy games out there that will perform bad no matter how much GPU power you throw at them, people just need to remember that and not think it is a problem with their hardware. Skyrim is definitely shoddy at the moment.

As far as Benchmarks go (something I don't personally put too much stock in) I got around 13k 3dmarks in 3dmark 11 and almost 40k in Vantage with my setup as I run it every day without making extreme tweaks for a better score if that means anything to you.


To the O.P. whoever told you that is was a "gimmick" is flat out wrong and uninformed, it has some issues for some people but it definitely works. However from what I have seen/read SLI is better.
November 27, 2011 5:39:55 PM

Your Better Off Just Avoiding SLI/Crossfire And Just Getting The Fastest Single Card You Can Find/Afford (eg;GTX580) Its Only Usefull If Your Running Very High Resolutions Above 1920x1200 Or Multi-Monitor Gaming
November 27, 2011 6:13:34 PM

It all depends on the games you want to play, some its really good as ive said. I would really expect that when you spend as much on a system as i have that it should handle any game i want to play with good performance.
I did only go to the 2 cards to run 3X 23" monitors in eyefinity but had to drop the settings down below what i wanted that i just ended up back at 1 monitor. The 3 monitor set up is really impressive but the performance loss wasn't worth it after a while.
Yes it dose work but not for everything by far, not for many new games until the manufacturers bring out the driver update after the game release. ATI still haven't sorted Sky rim and prob Nvidia have.
November 27, 2011 7:12:11 PM

Energy96 said:
There are a few poorly coded or new and still buggy games out there that will perform bad no matter how much GPU power you throw at them, people just need to remember that and not think it is a problem with their hardware. Skyrim is definitely shoddy at the moment.


I couldn't agree more.
November 27, 2011 7:17:06 PM

Mousemonkey said:
How do you work out percentages then? Some of those graphs show near on double the framerate.


I was wondering that too.
November 27, 2011 7:19:18 PM

Gothams Finest said:
I was wondering that too.

Hmm, kids these days huh?
November 27, 2011 8:42:03 PM

Pretty sure AbdullahG is just calculating the difference between the frame rates :p 
November 27, 2011 10:23:51 PM

My bad. I was referring to single card performance being 30 to 50% slower than dual card performance. That' what I was pointing at, though I may have stated it wrong. I was using dual card performance as a base, rather than single card.

Ex:
2x HD 6950 = 60FPS
1x HD 6950 = 30FPS <---50% slower than dual-card setup
November 28, 2011 10:37:23 PM

I've had cf5850's as well as my current crossfire hd6950 2gb sapphire dirt 3 edition cards, and I run triple eyefinity at 5760 by 1080 and crossfire helps alot on most games, way more than 30 percent
November 29, 2011 1:07:44 AM

wow......there is a whole lot of mis/untrue/incorrect information in this thread....may i suggest a mod bury it before someone mistakenly passes up on a second gfx card
November 29, 2011 2:02:15 AM

The only misinformation was by Bushrat (the OP) and Abdullah.
November 29, 2011 2:11:49 AM

Energy96 said:
The only misinformation was by Bushrat (the OP) and Abdullah.

Though I corrected myself...
November 29, 2011 2:56:50 AM

AbdullahG said:
Though I corrected myself...



Yes you did, but originally it was misinformation. I wasn't poking at you, I was just pointing out there was very little misinformation here and all of it was corrected.
November 29, 2011 4:01:57 AM

Energy96 said:
Yes you did, but originally it was misinformation. I wasn't poking at you, I was just pointing out there was very little misinformation here and all of it was corrected.

It's fine. I didn't take it personally, as it was never intended to be an insult.

@OP
To answer your question:
Yes, CrossFire works. It-on average-doubles the performance vs a single card setup with the same card. Two HD 6950 1GB will outperform a single HD 6950 (whether it be 1GB of 2GB). However, no all games support CrossFire or work well with it.

EDIT: 60% to 80% performance boost
November 29, 2011 4:48:01 AM

I don't like that "doubling" word. Very few games show perfect scaling. As I've mentioned before, you'll probably see anywhere from 60-80% increase in most titles.
November 29, 2011 8:57:22 AM

I agree, 60% to 80% is about right.
November 29, 2011 9:49:31 AM

I'll put in my two cents. I've spent the past few months getting my 2x6870s into working order. Sometimes (in the case of Metro2033) it was a simple plug and play. Installed cards, got 60 frames. It was incredible.

And then there's Skyrim, BF3, Cryostasis, Crysis 1 and 2, and a multitude of other games that took me a good while (several weeks) to get working. It's like with every game release comes a few days of tinkering to get your system working with it. So far I haven't met a game I couldn't play, but some were definitely compromises.

I would tell you to go Nvidia, but they have their share of problems, too. No crossfire setup is perfect, and it would be a bummer to drop $500 on an Nvidia SLI setup and have to fiddle with it to get it to work, too.

I say its worth all the effort if you actually play games that need it. I never thought I'd see playable framerates in Metro2033 or Cryostasis, but I do now. Also, keep in mind, Crossfire shines best at high resolution, so if you aren't playing in 1080 its not quite as worth it. The fact of the matter is if you want to play it like its meant to be played, dual gpu setups will certainly get you closer to that goal (for the most part).
November 29, 2011 7:18:49 PM

Okay, 60% to 80% on average is the final performance boost estimate.
November 29, 2011 9:10:43 PM

SpamShadow said:


And then there's Skyrim, BF3, Cryostasis, Crysis 1 and 2, and a multitude of other games that took me a good while (several weeks) to get working. It's like with every game release comes a few days of tinkering to get your system working with it. So far I haven't met a game I couldn't play, but some were definitely compromises.

I would tell you to go Nvidia, but they have their share of problems, too. No crossfire setup is perfect, and it would be a bummer to drop $500 on an Nvidia SLI setup and have to fiddle with it to get it to work, too.




I can't even fathom why that would be necessary, Crossfire is absolutely abysmal if you are having to do that. Fiddling for weeks?? with what?? I have never had even a single issue with my SLI 580's on any of the games I have played. I have never done anything beyond simply install the newest driver when it is released about every month.

I know skyrim has had a few issues for people, not just with SLI, but that game's coding is complete trash in spite of its really nice looking graphics.
November 29, 2011 9:16:53 PM

4745454b said:
I don't like that "doubling" word. Very few games show perfect scaling. As I've mentioned before, you'll probably see anywhere from 60-80% increase in most titles.


I think it really depends a lot on your resolution. If you are already getting frames in the 80 plus department at typical 1080 resolutions with a single GPU SLI isnt going to boost you as much as when you are running at 1440 or even 1600 resolution. I know in most really demanding games for me at 2560x1440 with max settings when I turn off SLI for giggles My frames drop by roughly half on average. (60-80 fps to 30-40 fps for example) Granted, many of those games also run well over 100fps in many points in the game. Frames can vary a lot in a game depending on what is going on, but my min frame-rate is definitely roughly double.

SLI really shines when playing at higher resolutions in my experience.
November 29, 2011 11:59:11 PM

Energy96 said:
I can't even fathom why that would be necessary, Crossfire is absolutely abysmal if you are having to do that. Fiddling for weeks?? with what?? I have never had even a single issue with my SLI 580's on any of the games I have played.


You'd be surprised how many hours you can spend changing out RadeonPro profiles and settings, trying different drivers, researching on the web. A lot of times it comes down to simple driver/game updates. I do hear a lot more people saying that don't have problems with SLI than Crossfire.

Sometimes it was just a single setting, something to do with AA or somesuch nonsense. Changing it would make the difference between the game running and not running. I tend to attract issues when it comes to computers...
November 30, 2011 11:22:01 AM

Generally speaking I believe you should always go for the most expensive card you can afford and run it on it's own. Crossfire is too much of a loose cannon at the moment in terms of compatability and drivers to consider for new-builds.

My stance on crossfire is that it gives you the opportunity later on to buy a duplicate card a year or so down the line when it's much cheaper - upgrading your rig. Rather than buying an entirely new 'hot' card all over again.
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