Tempted to try Crossfire - what are the downsides?

[AnitaPeterson]

Hi folks,

I've been thinking for a long time now to try a Crossfire setup, and right now I'm just about ready. But I have some questions, so if you have experience with multiple AMD videocards, please provide you input!

OK, so I plan to use two Radeon HD 7770 cards. I already have one HD7770, and I can get a second one for about CAD100...


So here are my questions:

1) As per AMD's less-than-detailed chart, these cards require a bridge. I have a bridge that came with my old 3850 - I assume the design is the same?

2) While reading about Crossfire on the web, I saw micro-stuttering being mentioned. Is this still an issue? Are there any definitive software solutions? I'm usually playing first-person shooters, I'm not particularly into RTS and MMORPGs.

And, for the record, the system runs an FX6300 and 24 GB RAM.

3) Also, is it enough to just unplug the system, insert the second video card, connect it to the first one with the bridge, then turn the computer back on? I don't see a Crossfire option in my AMD (Catalyst) Control Centre - will this option become available once a second card is detected?

4) Last, but not least... what kind of performance gain am I realistically looking at? Are two 7770s in Crossfire powerful enough to provide an alternative solution to a single 7850, or even a 7870?




Thanks much!

 

[Shmee]

Hey, first, I believe the old bridge will still work. I don't think SLI bridges or Crossfire bridges have changed in a long time.

As for the micro stuttering and smoothness issues, I had 6950 crossfire a while back, and while not perfect, it worked pretty well for my tastes. If you get the latest drivers (13.8 beta 2) you should be pretty well set for crossfire, these fix a lot of the issues.

As mentioned about the drivers, I would probably install them first just to be safe; not sure what set you are running now. Once that is done, install as mentioned, and upon boot it will ask you to enable.

As for performance boosts, depends on the game, and your other specs, such as CPU and monitor resolution. If you have a decent res monitor, you may want to upgrade to a card (or 2) with more Vram, I believe your current one has 1GB? Of course this is moot if you are CPU bottle necked.

 

[BrightCandle]

1) You normally get them with the GPU. You can buy them separately however.

2) Its still an issue, much less so than it was before but in DX9 and eyefinity its still as much a problem as it was before. AMD has a driver out now (beta) that brings frame pacing which reduces the microstutter to a level worse but similar to NVidia's solution. The amount of stutter present is still 10x more than a single card.

3) Don't forget the power plugs. But yes that is basically all you need to do. The option will then become available, if not reinstall the drivers and it will appear.

4) It can be up to 2x performance. But in some games you will get worse performance and will be required to turn it off and in others you'll see minimum gains. Most of the time it will bring about 70-80% extra performance.

Personally I wouldn't go crossfire until you have exhausted the performance of a single card and then I would choose NVidia's SLI over crossfire as it stutters less.

 

[AnitaPeterson]

[...] 4) It can be up to 2x performance. But in some games you will get worse performance and will be required to turn it off and in others you'll see minimum gains. Most of the time it will bring about 70-80% extra performance.

Personally I wouldn't go crossfire until you have exhausted the performance of a single card and then I would choose NVidia's SLI over crossfire as it stutters less.

Oh, rats... I was afraid of that...

 

[Shmee]

I in general agree about getting a more powerful single card first. I see you updated your specs, those are good, but we still need to know what games and at what res you plan on playing.

 

[mizzou]

In general, it's better financially and performance wise to just get a powerful single card.

 

[Elfear]

1)

Personally I wouldn't go crossfire until you have exhausted the performance of a single card and then I would choose NVidia's SLI over crossfire as it stutters less.

Agree with the single card route. If you can get a 7870 for a good deal, I would go with that over Xfire 7770s.

With regards to more stuttering I think the key term would be perceptible stuttering. While Crossfire has a bit more stuttering than SLI, all of the reviewers that I looked at couldn't perceive a difference.

DX9 still needs some work but even then a framerate limiter works well. That's what I used in Borderlands 2 and it worked beautifully.

 

[Shmee]

7950 over 78xx if possible

 

[NTMBK]

Buy a stronger single card (e.g. 7850), and resell the 7770.

 

[spat55]

I wouldn't bother, I really like my setup, but if they were any less than a HD 7850 I don't think it would be worth it, right now I get more than HD 7970Ghz performance when they scale perfectly, which was perfect as I got the second card for £100.

 

[Mondozei]

Crossfire is going to become much more viable as an SLI-solution than it has been.
Remember, Nvidia does framepacing too, so AMD is basically just doing what Nvidia does.

The reason why they didn't is because framepacing introduces small delays(it gives more ms before what happens shows up on screen), this is deliberate in order to give a smoother experience. Of course, most people will not notice this, but between microstutterings, an AMD crossfire solution would give you what was happening with smaller delays, but that would then be ruined by said stuttering with the intervals.

As have been pointed out, AMD is already fixing this and the coming drivers will more or less eliminate this as a problem(so don't worry it's a software thing, not a hardware thing).

My bottomline is: going forward, Crossfire will be basically on par with Nvidia's SLI solution as new drivers get released. I would still not recommend going SLI because you usually don't get 2x the performance but around 70% and sometimes even less than for a single card. A single card is far more consistent.

 

[AnitaPeterson]

OK... So far, I have five votes for a more powerful single card, and most of these suggest the 7850 at the very least.

Here are my purchasing options (they're all Sapphire brand):

1) 7770 - CAD110
2) 7850 (1GB) - CAD160
3) 7850 (2GB) - CAD180

 

[Jacky60]

I would get another 7770. I've used crossfire for over three years and while it hasn't always been perfect it's offered amazing performance and really impressive gains. The cheapest easiest way to improve your performance enormously is xfire. Edit: Actually the 7770 is pretty crap, get two 7950's and you'll be happy!

 

[ruhtraeel]

In this case, I might actually recommend Crossfiring. 7850 is more expensive and doesn't have as much of a performance boost.

As you can see here: http://www.techpowerup.com/reviews/HIS/HD_7750_7770_CrossFire/5.html

7770 crossfired, when it has good scaling (this has improved a lot during the current generation), gets similar FPS to a 7950, which in your case, would be less than half the price. It seems like it scales well (except Batman and some others in that review), and a lot of the times it seems like it turns something from being unplayable (20-25 FPS) to playable (40 FPS).

If you get a 7850, resale value would be worse, and your performance gain would be really small I think.

With some quick Shopbot searching and Memory Express price beating, it seems like you can get the 7770 for under or exactly $100.

However, it would all come down to your budget. If you are seriously constrained and can't spend more than $125, another 7770 is a good choice. If you can spend more, you can get a 7950 or something.

 

[Smoblikat]

HD6970 quadfire here, your old bridge should work fine. As for microstuttering I have never experienced it before, and after the 13.8 drivers people seem to be reporting it less. You could try radeonpro to tweak your display setting if you want too.

 

[raghu78]

CF at the low end is a bad idea. the cards have less VRAM and poor bandwidth. so you cannot run high AA without hitting VRAM bottlenecks. right now the best bang for buck card is HD 7950.

http://www.newegg.ca/Product/Product...82E16814202026

definitely try and spend the extra money to get a HD 7950.

 

[Binky]

I think the horse is still dead, so I'll beat it some more.

Crossfire on anything less than 7950/7970 is just silly. You'll have less heat, less noise, less hassle, and less stutter on a single card. There's really no downside of a single card until the fastest card available isn't fast enough.

 

[UaVaj]

Personally I wouldn't go crossfire until you have exhausted the performance of a single card and then I would choose NVidia's SLI over crossfire as it stutters less.

7970 xfire to 680 trisli.

share the exact same sentiment.

 

[tweakboy]

The drivers.

 

[raghu78]

In this case, I might actually recommend Crossfiring. 7850 is more expensive and doesn't have as much of a performance boost.

As you can see here: http://www.techpowerup.com/reviews/HIS/HD_7750_7770_CrossFire/5.html

http://www.techpowerup.com/reviews/HIS/HD_7750_7770_CrossFire/22.html

that review shows HD 7770 CF has a 65% avg improvement over single card.

now lets look at a review much later after 12.11 never settle drivers

http://www.techpowerup.com/reviews/HIS/HD_7950_X2_Boost/28.html

1920 x 1200
HD 7770 - 42
HD 7850 - 66
HD 7870 - 82
HD 7950(950 Mhz) - 100
HD 7970 Ghz - 115

HD 7850(1.15 Ghz) matches HD 7870 and HD 7950 at 1.125 Ghz matches HD 7970 Ghz. on average HD 7770 CF (42 x 1.65 = 69.3) would be slower than even a HD 7850 at 1 Ghz because not every game scales perfectly at 1.8 - 1.9x.

However, it would all come down to your budget. If you are seriously constrained and can't spend more than $125, another 7770 is a good choice. If you can spend more, you can get a 7950 or something.

even if the OP can spend USD 100 he can easily sell the HD 7770 for USD 70 and get a HD 7850.

http://www.newegg.ca/Product/Product...82E16814131473

OP forget HD 7770 CF. sell your card and spend the max you can to get a HD 7800 card or HD 7950. :thumbsup:

 

[bwanaaa]

if two cards have different clocks, does it matter which slot they go into?

 

[DDRGamer]

As someone who had a similar issue, it mainly rests on how much futzing around you want .

Crossfire may work fairly well, but requires you to buy another newer (albeit slower card) and you'll have slightly more finicky settings to use (not to mention two cards to sell when you upgrade)

A single upgrade is seamless, but definitely costs more money upfront.


I balked at paying $200 ($180+tax) for a new card, and ended up getting an XFX 7850 (2Gb) for $140 - If you don't mind navigating those waters, then a single card upgrade becomes very viable.

 

[AnitaPeterson]

Any advantages in getting the 2GB 7850 for $20 over the 1GB version?

 

[jacktesterson]

Any advantages in getting the 2GB 7850 for $20 over the 1GB version?

I have a 2GB Gigabyte 7850 in excellent condition for sale... Its factory overclocked to 975MHz Core rather than stock 860 MHz so its handy to a stock 7870.

Let me know if your interested - Just thought I'd mention it to save you some more money.

 

[jacktesterson]

Any advantages in getting the 2GB 7850 for $20 over the 1GB version?

Also...

go with 2GB model - So you can take advantage of buying a 2nd 7850 when needed without being Memory limited. (At least in today's games, 1GB for 1080p per Card is usually sufficient for most)