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HD 6870, worth getting another for Crossfire?

Last response: in Graphics & Displays
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January 16, 2012 1:30:38 PM

Hi Everybody,

I have a question about CF.
I bought my system in December 2011, and designed it for future Crossfire, soon. Unfortunately, after reading and learning about it more I'm not so sure now... Please tell me what you think about those:

1. CPU bottleneck: I asked and read online and couldn't get a final answer whether my CPU will bottleneck 2 6870s or not. I'll probably buy the Hyper 212 Plus and OC my CPU to 3.6 or 3.8 GHZ, but it still bother me since I heard that bottleneck can cause problems with CrossFire/SLI.

2. Micro-Stuttering of course, and other issues: I don't want to spend more than 175$ and get worse performance than what I get now. I read many reviews about those cards in CF, only 2 talked about scaling and said it was good, and overall it is very recommended. There is also that YouTube channel that I found, GameTester22, that has a similar rig to mine and it looks he has no issues. On the other hand, I read the review from Tom's about Crossfire/SLI and saw the problems, and I read many thread complaining about this setup as well. 2 people in some threads called it "EPIC FAIL".

3. Memory: CrossFire is not doubling the VRAM. I know that games such as BF3 or Crysis 2, need more than 1 GB of VRAM to be played well on ultra settings on 1080p. I don't want the memory to bottleneck the cards and cause more problems and issues...

My System:
AMD Phenom II 955
GA-890GPA-UD3H
G.Skill ECO 4GB @1333 CL7 (Will probably add one more kit for 8GB total)
SAPPHIRE HD 6870 1GB (reference model)
Corsair HX 850W
ZALMAN Z7 Plus
LG E2260T monitor

I don't know what to do, I waited for long and now I am kind of disappointed... Any suggestions or advice will be appreciated.
Thank you! :) 

More about : 6870 worth crossfire

January 16, 2012 1:49:52 PM

Here is my opinion on the subject.

It is a well known fact that Xfire 6870s will be quicker than a single 6970 or even GTX580 in many cases.

Those who call the Xfire setup with these cards "EPIC FAIL" are idiots. Plain and simple. Idiots without the patience to get the 2 cards working in unison. As a result they get frustrated and bored and give up and call it AMDs fault for creating a terrible combination.

The 2 cards will not work perfectly out of the box. They will require some tweaking, some driver changes maybe - some patience. But once ready they will not dissappoint.

Unfortunatly all the issues associated with Xfire are real, and cannot be avoided entirely. Some games will pose an issue and will simple not run on Xfire.

Games such as BF3 will require some tweaking but hitting the sweetspot of AA/AF will result in excellent performance - much higher than that of a single one. Most people expect to play on 16x MSAA - this eats your VRAM as as you mentioned, the 6870s dont really have that much.

Your CPU will pose a bottleneck in games such as Skyrim, where a single 6850 can max out the graphics on 1080p with little or no issues. These are extremes though, and with a little overclocking (to 3.8ghz should do nicely) you will hit that loverly barrier between sluggish and smooth, and sail away on calm waters.

For $175 your getting a potential 100% increase in performance in very rare cases, and I would say a steady increase in performance of around 40 - 60%. I say worth it.

If you are patient and willing to give it a try, buy another one. If you think you will get frustrated easily, do not.
January 16, 2012 1:55:48 PM

I have 1090t at 4ghz and recently added a second 6870. My frames basically doubled in BF3.

1. You may have a slight bottleneck compared to a 2500k or higher, but not a dealbreaker. You will definitely notice an increase in smoothness.

2. I haven't experience any microstuttering. I've seen it on your tube, but in my personal experience gaming (BF3, BC2, Quakes, Unreals, Half Life 2, all @ 1080p i've yet to experience it.

1. At 1o8op Your OK, above that, VRAM plays a part.

6870 crossfire is faster than a GTX580 stock, so value for money its hard to beat. And with your processor, upping your NB to at least 2600 is very beneficial.
Related resources
January 16, 2012 2:57:39 PM

I am running HD6870's in CF with little problems at all, before I updated my CPU I ran my crossfire setup on a Phenom II 945, which is a locked version of your same processor. My performance in almost every game is superior to a single 6970. Deadjon is correct about your CPU in skyrim, my CPU was overclocked at 3.5GHz and I still had some FPS issues mostly just in whiterun but it wasn't unplayable and most everywhere else the game play was smooth.

With some games you will need to disable CF because they simply do not support dual graphic card setups, this isn't really that big a deal for me as one HD 6870 is still a pretty powerful card on its own. I get a score of 1630pts when I run Unigine Heaven benchmark which is really good. I can't see any reason not to CF just be ready for a few driver issues here and there, but as long as you stay up to date with AMD released drivers and a few preview drivers you'll be very happy with your upgrade.
January 16, 2012 3:14:23 PM

I agree, get yourself another card. Ignore the horror stories around CF.

The extra 4GB of memory is going to be great as long as your windows install is 64-bit.
January 16, 2012 3:56:02 PM

There will always be issues with mutli-gpu configurations. You may get a little fustrated if you get games at launch, as recently with skyrim you had to wait for AMD to post updated drivers for crossfire to work. Thankfully AMD will be allowing you to make your own custom crossfire profiles with future drivers so it won't be as bad. Yes your CPU will limit your performance in some cases but you will still get a good performance increase and I recommend you OC your CPU to get the most out of it :D 

Go crossfire. Be happy
January 16, 2012 4:07:15 PM

Thank you all!
Unlike other forums, you reply fast and you really help, finally.

deadjon said:
Here is my opinion on the subject.

It is a well known fact that Xfire 6870s will be quicker than a single 6970 or even GTX580 in many cases.

Those who call the Xfire setup with these cards "EPIC FAIL" are idiots. Plain and simple. Idiots without the patience to get the 2 cards working in unison. As a result they get frustrated and bored and give up and call it AMDs fault for creating a terrible combination.

The 2 cards will not work perfectly out of the box. They will require some tweaking, some driver changes maybe - some patience. But once ready they will not dissappoint.

Unfortunatly all the issues associated with Xfire are real, and cannot be avoided entirely. Some games will pose an issue and will simple not run on Xfire.

Games such as BF3 will require some tweaking but hitting the sweetspot of AA/AF will result in excellent performance - much higher than that of a single one. Most people expect to play on 16x MSAA - this eats your VRAM as as you mentioned, the 6870s dont really have that much.

Your CPU will pose a bottleneck in games such as Skyrim, where a single 6850 can max out the graphics on 1080p with little or no issues. These are extremes though, and with a little overclocking (to 3.8ghz should do nicely) you will hit that loverly barrier between sluggish and smooth, and sail away on calm waters.

For $175 your getting a potential 100% increase in performance in very rare cases, and I would say a steady increase in performance of around 40 - 60%. I say worth it.

If you are patient and willing to give it a try, buy another one. If you think you will get frustrated easily, do not.


I'm not going to play Skyrim so I think I should be fine, and I believe I have enough patience... thanks.

Deedot78 said:
I have 1090t at 4ghz and recently added a second 6870. My frames basically doubled in BF3.

1. You may have a slight bottleneck compared to a 2500k or higher, but not a dealbreaker. You will definitely notice an increase in smoothness.

2. I haven't experience any microstuttering. I've seen it on your tube, but in my personal experience gaming (BF3, BC2, Quakes, Unreals, Half Life 2, all @ 1080p i've yet to experience it.

1. At 1o8op Your OK, above that, VRAM plays a part.

6870 crossfire is faster than a GTX580 stock, so value for money its hard to beat. And with your processor, upping your NB to at least 2600 is very beneficial.


Which driver are you using? 12.1a? You always download CAPS when they are released right?
And about the NB, my CPU isn't a BE one (sadly...), so I am going to overclock it with the base clock of course, which will raise the NB frequency and my RAM as well. I'm planning on 240 so my RAM will function as it should at 1600MHz, shouldn't be a problem right?

rage33 said:
I am running HD6870's in CF with little problems at all, before I updated my CPU I ran my crossfire setup on a Phenom II 945, which is a locked version of your same processor. My performance in almost every game is superior to a single 6970. Deadjon is correct about your CPU in skyrim, my CPU was overclocked at 3.5GHz and I still had some FPS issues mostly just in whiterun but it wasn't unplayable and most everywhere else the game play was smooth.

With some games you will need to disable CF because they simply do not support dual graphic card setups, this isn't really that big a deal for me as one HD 6870 is still a pretty powerful card on its own. I get a score of 1630pts when I run Unigine Heaven benchmark which is really good. I can't see any reason not to CF just be ready for a few driver issues here and there, but as long as you stay up to date with AMD released drivers and a few preview drivers you'll be very happy with your upgrade.


Which drivers are you using? And could you specify games that run well or games that don't? (like ones you better disable CF)?

cirdecus said:
I agree, get yourself another card. Ignore the horror stories around CF.

The extra 4GB of memory is going to be great as long as your windows install is 64-bit.


Yes, of course I am using 64 bit.

Thank you!
January 16, 2012 4:08:45 PM

I think the largest concern is the new games almost never work. You always have to wait for AMD to release new drivers.

I crossfired for a couple years, but when it came time to upgrade I didn't even consider a 2 GPU solution.
January 16, 2012 4:17:34 PM

I had to download the 12.1a preview drivers for CF to work in Skyrim. But generally all the updated drivers work well with most my games, I'm very happy with my CF setup. The only game that I play that I can not get CF to work in is NFS: Shift 2, if I don't disable CF the lights flicker. It's not unplayable but annoys me to where I just disable CF. Dirt 3, Battlefied 3, Skyrim (now), Rage, Shogun 2, all work splendid with CF.
January 16, 2012 4:20:05 PM

Ok thank you both, and jsrudd - I don't mind waiting a month or two, it's not that I buy all new games on day one... your CF setup was that bad?
January 16, 2012 4:30:04 PM

Totally worth it, when you can't buy a single card like 6970.
January 16, 2012 4:44:48 PM

OK anyone else? Deedot78 can you answer my questions please?
January 16, 2012 10:31:13 PM

I say totally worth it :D 
January 17, 2012 10:01:03 AM

I'm using 11.12 as of right now, i do downloads caps as needed. You dont always have to have the latest drivers, sometimes they actually regress some games. And as far as your NB, no its not a problem, but it well known that Phenom II benefit greatly from NB of 2600.
!