2x 7870 CF or 1x 7970? What's best for 5760x1080 gaming

darreng101

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Hi guys,
I've just ordered a Sapphire 7970 o/c and am having serious questions if I did the right thing. I need to change the order in about 10 hours if I want to.

I think I might have been better with 2x Sapp 7870 o/c running in CF.

The purpose is to run 3x eyefinity at 1080p.

The 7870s cost 30% more now but I know I won't spend another $500 later on a second 7970, and with the 7970 oc model taking up 3 pci slots they are hard to fit into most mid range Mobo's at 16x/16x. I can fit the 7870s at 16/16 in my current Mobo.

I know the concept of buy the best single card you can afford but I did that with my last graphics card and never got a second....

Will the dual 7870s kick the a£$e of the single 7970 in eyefinity 1080p? I can't find any directly comparable review on Tom's.

Thanks for any quick advice.

Cheers, Daz
 
Solution
At first I would've agreed. I've heard that the new 7xxx series cards scale really well but I've also heard about driver complaints. Then I decided to poke around and found this on TechPowerUp.

http://www.techpowerup.com/reviews/AMD/HD_7950_CrossFire/23.html

TweakTown certainly isn't my go to site for reviews. I only linked them because that was the only review I could find that was addressing your exact situation. I've read some stories where they have a checkered history with NDAs and things like that but honestly I cannot comment on the validity of their numbers. So I can't say they are invalid.

But according to the TPU review for the 7950, @ all resolutions, a single 7950 performs at 73% of a crossfired pair (They...

AdioKIP

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Yes, two 7870's in crossfire will be faster than a 7970, but the 7970 isnt a bad choice at all. Either choice should get you acceptable playability at EyeFinity resolutions, just dont expect to be able to max every game regardless of which setup you choose.

You said you wont ever add a second 7970 in the future, but why not. In a year or two when prices have dropped some more why not keep that open as an upgrade path, although having the 3 slot design does make it harder. This was why I avoided certain cards when I was upgrading.

I upgraded about 2 weeks ago to a Sapphire 7950 OC edition and overclocked it to match a stock 7970. I run an EyeFinity setup and so far love the 7950. Most games I've thrown at it its been able to run maxed out even in EyeFinity resolutions (MS Flight, Diablo 3, Saints Row 3) others I'll have to drop some settings a notch or two. Either way you go you should be just fine.
 

rdzona

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Well it really depends on what kind of performance you're looking to get and what your budget is. I personally would stick with 1 7970 (OC it of course) versus 2 7870s. 7870s retail for like 350, so you're talking 700 which is quite a big jump but I don't think the performance would match the price jump.

http://www.tweaktown.com/articles/4597/amd_radeon_hd_7870_2gb_reference_video_cards_in_crossfire/index4.html

This was what I found just doing a quick search. To me there isn't enough performance jump to justify the cost. Now you already said 2 7970s are out of budget, but you're considering 2 7870s, so if you can stretch just another 100 dollars I think 2 7950s would be a great middle ground. Just at stock clocks there is a much bigger jump in performance, they almost double a 7970s performance. Plus 7950 have lots of headroom, even with mild overclocks you should be doubling 7970 performance no problem.
 

darreng101

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I've just found this review of the 7870 single card compared to the 7970

http://www.techspot.com/review/504-amd-radeon-7870-7850/

Metro 2033 DX11 max qual AAA/16x AF@1920x1200... 56 vs 72fps or 28% better
Metro 2033 DX11 max qual AAA/16x AF@2560x1600... 32 vs 42fps or 31% better

It seems in most games the range for performance between the 2 cards is +15-30% fps to the 7970

Is it to simplistic to say 2x7870 in CF-X should on average achieve +60-70% fps over the single card
 

darreng101

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I like the way you think rdzona.

From my preferred supplier the 7970 oc is au$575
The 7870s are 376 ea or 752
A 7950 non oc is 471 or 942 so it's $190 more

$942 is $367 more than the 0c'ed 7970 but it would kick arse overclocked?...
It's a lot of extra money given I'm also ordering an ssd and extra HD with this purchase.

Maybe I just go the 1x7950 and look at another in 3-4 months as it will fit on my Mobo at 16x/16x.....
 

AdioKIP

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A 7950 is a great card. I have mine overclocked to the stock levels of a 7970. Going with a 7950 will get you performance now and leave you an upgrade path in the future since you can add another to crossfire.

If you can, get something like the sapphire oc 7950. The factory overclock isnt a big deal but the difference in the dual fan cooler and the reference design makes the OC cards better for higher overclocks.
 

darreng101

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Have just been reading @rdzona tweaktown review. It seems to indicate the 7xxx series cards scale in CF really well, like 80-90%
The reason I'm still leaning towards the dual 7870oc is that in 12 months my i7 950 might need upgrading which will also mean a new Mobo/cooler and ram and I won't also be able to outlay for a second GPU as well.

Do you trust the tweaktown CF scalings (about 85% average) and difference between the 78xx series and 79xx (not a huge amount)
 

rdzona

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At first I would've agreed. I've heard that the new 7xxx series cards scale really well but I've also heard about driver complaints. Then I decided to poke around and found this on TechPowerUp.

http://www.techpowerup.com/reviews/AMD/HD_7950_CrossFire/23.html

TweakTown certainly isn't my go to site for reviews. I only linked them because that was the only review I could find that was addressing your exact situation. I've read some stories where they have a checkered history with NDAs and things like that but honestly I cannot comment on the validity of their numbers. So I can't say they are invalid.

But according to the TPU review for the 7950, @ all resolutions, a single 7950 performs at 73% of a crossfired pair (They normalized based on the CF7950s). Meaning you are only gaining 27% by adding in a secord card. Doesn't seem that great to me.

Personally I've always thought of CF as a mix bag, and I generally have thought that if you can get an extra 50% out of the second card then its probably worth it if you need it. I've always been a fan of single card solutions myself. Also CF is also one of those things that evolves quite a bit based on drivers and the games coding. So AMD could release 12.5 drivers tomorrow and have incredibly improved CF performance and scaling in new titles.
 
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Zephids

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I'd also like the point out, just as the original poster pointed out, the 7970s typically take more than 2 card slots. I know mine does, I own a Sapphire 7970 OC. This means that unless you purchase a new motherboard or specific 7970 models, you will NOT be able to CF in the future.
 
OK, as said above it depends on how much do you expect to see when running the eyefinity. A single HD 7970 will never maintain a good playable FPS when you play @ high quality settings with such a massive resolution.
Best way to go is to grab 2 HD 7950s, they are great overclockers once you crank them up you surpass HD 7970s levels while saving $140.

Or the best bang for buck is to grab 2 GTX 670s, a single GTX 670 beats a single HD 7970 @ stock speeds while costs less, running 2 of them will give you the maximum performance for 3 monitors gaming.
 

Zephids

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The GTX 670s will be your best bang for buck given 2 conditions:

1) You have ~$800 to spend.

2) You can FIND GTX 670s in stock.

Newegg has EVGA GTX 670s out of stock. Just checked before posting.
 

rdzona

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Cmon, let's be real here. I wouldn't say a single 670 "beats" a single 7970 at stock clocks. I would definitely say it's a tie though. Although one could argue that gpu boost kind of muddies up them waters when talking and comparing "stock clocks".

http://www.hardocp.com/article/2012/05/14/geforce_680_670_vs_radeon_7970_7950_gaming_perf/2

Out of the four games tested, its technically split, 2 games each. But oc that 7970 and well.....
 

hannibal

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One card is allways easier to handle and more stable. But cossfiring or sliing is so common that it is ok route if you want to have speed. I prefer to have good single card and then look out the maket and think if a completely new card or second card provide better bang for the buck.
The trend seems to be that new smaller production technology is not free way of getting better and cheaper graphiccards in the future...
 


You just did a little mistake :p, that resolution favors AMD cards since the HD 5000 series rise up.
Looking at the majority 1080P benches;
gtx%20670%20vs%207970%201920.png

HD 7970 is very competing with GTX 680 itself above 1200P. And if you OC it it will crank up the GTX 670 and will be in the GTX 680 range.
 

monsta

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Well said , thank you for clearing that, someone knows what they are talking about.
 

darreng101

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670's are available in Australia though they are hard to find and when someone has one, you get little choice in terms of brands and models.

At my supplier 9 of 10 models are unavailable ATM and the one that is is an oc model at $532AU :( so out of my budget.

Thanks for the recommendation and yes I agree the 670s are an awesome gaming card, but I also do a fair bit of CPU intensive tasks which is why i'm only considering AMD cards.
 

darreng101

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I think it's actually an extra 27% over the 73%. The way the data is shown is a little confusing, eg if the cf shows 100fps and the single card 73 fps that's a 37% increase, and that's an average of all resolutions, most of which are low. At 1920x 1200 it's a 59% increase. Still well below tweaktowns though admittedly.

I've decided to go with 7870 CF and then overclock them a bit. I'm sure that will give what I need not to much over budget, at 16x/16x and without needing to spend more in the future and risk a single card is discontinued.


 

rdzona

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LOL, serioulsy? I can't believe he is going to fire back at me with benches from 1080 when we're talking about high end cards that are made for higher resolutions. And I would back [H]ard reviews over toms any day of the week.

"someone knows what they are talking about" I almost couldnt believe what I read LOL.

Why not test out the 690 on 480 standard definition?
 

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