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AMD Crossfire 6870? on a 960T?

2K views 33 replies 10 participants last post by  rdr09 
#1 ·
Hey guys!

Its almost christmas and i got a nice bonus, i was thinking of getting a new Tv....
But something in me is going ..... Pc needs Moar powa!!!!!
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I dont know if it is a good idea but, i have been using my Current 6870 Ati card for about a year now, and i am very pleased with its performance so far !

My Motherboard has a extra Slot to run 2 Videocards, i have a nice airflow in my Case , (i stil dont understand why videocards blow air down??)
But going to put a second 6870 card would worry me.

For starters, is my 960T CPU able to handle 2 of those cards?
And would my 650W Adata PSU be able to power both these cards on High loads with a OC 960T CPU?

And last , wouldt 2 of those cards get too hot? there should be a PCI express slot between the 2 cards so little room for airflow
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Just to be clear i dont want to upgrade any more parts, just add stuff to my Pc
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I just got a new Soundcard aswell gonna upgrade my sig rig so u guys can check it out
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I would love to hear your thoughts about this guys , its realy a itch but id like to be sure
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#3 ·
#5 ·
Quote:
Originally Posted by Barbecuesaus View Post

Wait what, getting a version of my card that blows air out the back
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How do i find that?
There are only 3 versions of this card i have, from XFX and they al have dual fans so i dont think what u say is possible
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PSU: http://www.adata-group.com/index.php?action=product_specification&cid=4&piid=94&lan=nl
You don't need to get another XFX one. Get any reference card and they will blow the air out the back.

http://www.ozone3d.net/public/jegx/201010/amd_radeon_hd6870_01.jpg

They look like that.

Also, your PSU will be fine handling two of them.
 
#6 ·
I dont need a second xfx?
I thought u had to have 2 of the same cards for Crossfire? Gosh im realy a noob on this subject.

And is a 580 good then , sinds it outperforms it? This is my first custom build pc so i dont have much to compare it with, i did however upgraded my CPU this year
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Pc is almost 2 years old
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And how far would my CPU need to be overclocked to not be a bottleneck? Or doesnt it need to be OC?

Also i hope u are realy sure about my PSU being able to handle.

I saw a chart where my 6870 would pull 300watts on full load, id figure x2 cards is about 600watts o_O 50 watts left for the rest of my hardware ? no way!!
But i may be wrong , i know the specs of my card say it needs a min of 150watts, but i have other hardware aswell.
4 fans, 2x HDDs 2 sticks of ram, the Videocard and a dedicated Audio card.
 
#7 ·
Quote:
Originally Posted by Barbecuesaus View Post

I dont need a second xfx?
I thought u had to have 2 of the same cards for Crossfire? Gosh im realy a noob on this subject.
And is a 580 good then , sinds it outperforms it? This is my first custom build pc so i dont have much to compare it with, i did however upgraded my CPU this year
smile.gif

Pc is almost 2 years old
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And how far would my CPU need to be overclocked to not be a bottleneck? Or doesnt it need to be OC?
Also i hope u are realy sure about my PSU being able to handle.
I saw a chart where my 6870 would pull 300watts on full load, id figure x2 cards is about 600watts o_O 50 watts left for the rest of my hardware ? no way!!
But i may be wrong , i know the specs of my card say it needs a min of 150watts, but i have other hardware aswell.
4 fans, 2x HDDs 2 sticks of ram, the Videocard and a dedicated Audio card.
They only have to have the same Chip, it can cause problems though as Lucid Hydra deals with this i think?

my 6870x2 runs With plenty of headroom on my 600w PSU
 
#8 ·
So problems? please tell me more o_O
What kind of problem can running 2 card actualy bring?

Maybe , i should think what kind of games would benefit for 2 cards
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Also i googled what this Lucid Hydra is..... http://www.legitreviews.com/article/1093/2/

So i can also buy a Nvidia card to run with AMD card
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This doesnt feel right u know?
 
#9 ·
Quote:
Originally Posted by Barbecuesaus View Post

So problems? please tell me more o_O
What kind of problem can running 2 card actualy bring?
Maybe , i should think what kind of games would benefit for 2 cards
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Also i googled what this Lucid Hydra is..... http://www.legitreviews.com/article/1093/2/
So i can also buy a Nvidia card to run with AMD card
rolleyes.gif
This doesnt feel right u know?
Crossfire can be a Pain in the ass. But when it works it is amazing.

Microstutter may/may not be an issue.
Driver Issues
Temps(i guess?)
Higher powerdraw
supported games limitations

Get RadeonPro and you will be fine
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#10 ·
it would be fine. I had a similar setup a while back (1090T and 6870CF) the experience I had with that setup is amazing. people seem to forget 6870 crossfire scaled amazingly well.
 
#11 ·
Quote:
Originally Posted by jprovido View Post

it would be fine. I had a similar setup a while back (1090T and 6870CF) the experience I had with that setup is amazing. people seem to forget 6870 crossfire scaled amazingly well.
yeah, the 6870x2 actually scales better than two 6870's in CF. such a sick card.
 
#12 ·
Quote:
Originally Posted by jprovido View Post

it would be fine. I had a similar setup a while back (1090T and 6870CF) the experience I had with that setup is amazing. people seem to forget 6870 crossfire scaled amazingly well.
Hello guys
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I have the HD 6850.Is it known for scaling as good as the HD 6870 because i would really want some extra performance?I know it's OFFTOPIC but i was just about to make a thread like that and then i saw this one and said myself that there's no need for a lot of pretty much simular thread so i wrote in this one.Will Seasonic S12II 620W be enought?Will there be a lot of micro struterring,driver issues etc.? Thx in advance.
Click In this review there's basically 100% scale in every game at 1080p
 
#13 ·
Quote:
Originally Posted by Noctizzle View Post

Crossfire can be a Pain in the ass. But when it works it is amazing.
Microstutter may/may not be an issue.
Driver Issues
Temps(i guess?)
Higher powerdraw
supported games limitations
Get RadeonPro and you will be fine
thumb.gif
What is Microstutter?
Driver Issues o_O No how? Doesnt amd have proper drivers for Crossfire?

And u say supported games Limitations? So does that mean if a game doesnt support Crossfire it just runs 1 card?
And last , what is RadeonPro
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?

Oh i didnt see ur second post, u say 6870x2 scales better then in CF?
CF= connecting the 2 cards right?
So having them x2 means not being connected, i didnt know this was possible
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----edit----

@hotwheels1997

I looked at your first build, u have a nice CPU btw!
But looking at your Case i would worry even more about heat!

Look at my Pc case , and i already worry about heat..... You should even more i assume o_O!!!?
 
#14 ·
Quote:
Originally Posted by Barbecuesaus View Post

What is Microstutter?
Driver Issues o_O No how? Doesnt amd have proper drivers for Crossfire?
And u say supported games Limitations? So does that mean if a game doesnt support Crossfire it just runs 1 card?
And last , what is RadeonPro
smile.gif
?
Oh i didnt see ur second post, u say 6870x2 scales better then in CF?
CF= connecting the 2 cards right?
So having them x2 means not being connected, i didnt know this was possible
mad.gif

----edit----
@hotwheels1997
I looked at your first build, u have a nice CPU btw!
But looking at your Case i would worry even more about heat!
Look at my Pc case , and i already worry about heat..... You should even more i assume o_O!!!?
Don't look at my pic,i'll get HAF 912 Plus around Christmas or in the beginning of january.Even with my current case,my cpu stays at under 70C @ 4.5Ghz(prime95,around 50-55 in games like BF3) and my GPU under 65 in Furmark,overclock to 950/1100.Once i get my new case,the temps would drop even more.Can't wait!!! Decided to go and get the PSU before the case though.
 
#15 ·
Oke, sound good airflow is important
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specialy with 2 cards id figure

My CPu says below 20C ^^ On full load !!
Overclocked i havent seen it go over 30

But GPU is a different story
I have seen my GPU work its way over 80 degrees! That was with a Game called Trine 2
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#16 ·
I have dual 6870s and on my old 965 be at 4 ghz i was still bottlenecked. With your 960 it has higher ipc and should hit 4.1-4.2 ghz overclock that would help. To the guy with the i5 you will be fine with crossfire. I switched to an i5 3570k and it made my cards come to life.
 
#17 ·
Quote:
Originally Posted by Barbecuesaus View Post

What is Microstutter?
Driver Issues o_O No how? Doesnt amd have proper drivers for Crossfire?
And u say supported games Limitations? So does that mean if a game doesnt support Crossfire it just runs 1 card?
And last , what is RadeonPro
smile.gif
?
Oh i didnt see ur second post, u say 6870x2 scales better then in CF?
CF= connecting the 2 cards right?
So having them x2 means not being connected, i didnt know this was possible
mad.gif

----edit----
@hotwheels1997
I looked at your first build, u have a nice CPU btw!
But looking at your Case i would worry even more about heat!
Look at my Pc case , and i already worry about heat..... You should even more i assume o_O!!!?
no, the 6870x2 is a Single PCB with two 6870's on it. Like a gimped HD6990, It scales better than actually having two 6870's in CF.
The card costs a ton more though
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#18 ·
Quote:
Originally Posted by conzilla View Post

I have dual 6870s and on my old 965 be at 4 ghz i was still bottlenecked. With your 960 it has higher ipc and should hit 4.1-4.2 ghz overclock that would help. To the guy with the i5 you will be fine with crossfire. I switched to an i5 3570k and it made my cards come to life.
I've watched some videos of HD 6850 in crossfire of ppl with AMD x4 965 BE etc. at 4.00Ghz or something and their card were at around 60-70%.With the i5 @ 4.5Ghz,will i be maxing out both gpu's? And btw,do you notice the micro-struterring everyone are talking about.
Quote:
Originally Posted by Barbecuesaus View Post

Oke, sound good airflow is important
biggrin.gif
specialy with 2 cards id figure
My CPu says below 20C ^^ On full load !!
Overclocked i havent seen it go over 30
But GPU is a different story
I have seen my GPU work its way over 80 degrees! That was with a Game called Trine 2
rolleyes.gif
How the f*ck?? Below 20C on full load is impossible for Hyper 212 Plus.
 
#19 ·
Quote:
Originally Posted by hotwheels1997 View Post

I've watched some videos of HD 6850 in crossfire of ppl with AMD x4 965 BE etc. at 4.00Ghz or something and their card were at around 60-70%.With the i5 @ 4.5Ghz,will i be maxing out both gpu's? And btw,do you notice the micro-struterring everyone are talking about.
How the f*ck?? Below 20C on full load is impossible for Hyper 212 Plus.
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at stock settings it runs 15C from Cold start (no load) Not sure as idle i dont run this CPU on stock its at 3.2Ghz now staying below 20.C i can post some screens if u want
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Too proof its not impossible (psst i have 2 fans
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)

Back on-topic

If my CPU bottlenecks 2x 6870's in crossfire Then i dont want too go crossfire, i feel then it would be a waist if not getting 100% out of my hardware.
With the risk of having games that not support crossfire, i realy have to consider this before going down this road.

Also i dont think my CPU can reach 4Ghz
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Tops i managed to get 3.8Ghz stable. But i am starting over my OC again for stock so thats why i am at 3.2ghz again now.
If u check my benchmarks u can see this 3.2Ghz clock performs better then my previous 3.4Ghz clock (i did have a 3.7ghz clock but didnt save it)
The thing was, my Ram was running single Channel duo me installed the ram in slot 1 and 3, when i should be in slot 1 and 2 >.> stopid hu? Yea i know.

Maybe i can get it clocked better but so far there is a performance difference id like to check out first
smile.gif
So who knows?

But im sure i cant get to 4Ghz
My goal is for a modest OC , with not too much Vcore increase because it runs realy cool, even at 1.47Vcore it says below 30 degrees

I have it on stock settings now , i think that is 1.37Vcore?
 
#20 ·
Quote:
Originally Posted by Barbecuesaus View Post

biggrin.gif
at stock settings it runs 15C from Cold start (no load) Not sure as idle i dont run this CPU on stock its at 3.2Ghz now staying below 20.C i can post some screens if u want
rolleyes.gif
Too proof its not impossible (psst i have 2 fans
wink.gif
)
Back on-topic
If my CPU bottlenecks 2x 6870's in crossfire Then i dont want too go crossfire, i feel then it would be a waist if not getting 100% out of my hardware.
With the risk of having games that not support crossfire, i realy have to consider this before going down this road.
Also i dont think my CPU can reach 4Ghz
mad.gif

Tops i managed to get 3.8Ghz stable. But i am starting over my OC again for stock so thats why i am at 3.2ghz again now.
If u check my benchmarks u can see this 3.2Ghz clock performs better then my previous 3.4Ghz clock (i did have a 3.7ghz clock but didnt save it)
The thing was, my Ram was running single Channel duo me installed the ram in slot 1 and 3, when i should be in slot 1 and 2 >.> stopid hu? Yea i know.
Maybe i can get it clocked better but so far there is a performance difference id like to check out first
smile.gif
So who knows?
But im sure i cant get to 4Ghz
My goal is for a modest OC , with not too much Vcore increase because it runs realy cool, even at 1.47Vcore it says below 30 degrees
I have it on stock settings now , i think that is 1.37Vcore?
prime95 testing for 1hour and post a pic of Realtemp
 
#21 ·
Sure will do
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im clocking 3,5ghz now and its at 27 degrees , il do a stock test when i have more time
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On-topic, im realy unsure if placing a second 6870 GPU would be good
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i see more disadvantages then advantages .....
 
#23 ·
Quote:
Originally Posted by Barbecuesaus View Post

Sure will do
rolleyes.gif
im clocking 3,5ghz now and its at 27 degrees , il do a stock test when i have more time
wink.gif

On-topic, im realy unsure if placing a second 6870 GPU would be good
redface.gif
i see more disadvantages then advantages .....
27 degrees,now that's completely different story from below 20C
wink.gif
Crossfire is good if you have the CPU to go with it.I'm pretty sure,even with my i5-3570k,i'll need to 24/7 run 4.5Ghz to not experience bottleneck,what's left for the Phenom x4,i guess you'll have to go 5.00Ghz for small to no bottleneck
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#24 ·
Quote:
Originally Posted by Barbecuesaus View Post

Sure will do
rolleyes.gif
im clocking 3,5ghz now and its at 27 degrees , il do a stock test when i have more time
wink.gif

On-topic, im realy unsure if placing a second 6870 GPU would be good
redface.gif
i see more disadvantages then advantages .....
People are scaring you away.

I assure you your PSU is easily able to do both of them. If you saw a graph of a single 6870 pulling 300W that is going to be from the wall and not what the PSU is actually using. There is an efficiency calculation that needs to be taken into place.. So if the PSU in question was 80% efficient the load would have been ~240W which is probably the case.

Also, as far as heat goes. All you need to do is get a reference 6870 like I said on the first page so it will exhaust hot air out the back and put your XFX on bottom. Temps will still be fine unless your ambient is through the roof. For CrossFire you only need the same GPU series, they do not need to be manufactured by the same company. EX; You could XFire a 6850 by Asus with a 6870 by XFX. (Just an example).

And, as far as micro-stutter/driver issues/etc goes. Now this is probably the only thing you should even be concerned with. While this is a very possible issue, AMD drivers have gotten better than they were in the past with the older series of cards. It's impossible to tell you if you'll experience micro-stutter or not but I can tell you there is a lot of people that can't even notice it. Since you don't know what it is based on previous posts in this thread, here is a link:

http://en.wikipedia.org/wiki/Micro_stuttering

As far as your CPU goes and bottlenecking, yeah it's not the best but you shouldn't bottleneck on most games. There are some very CPU intense games that will bottleneck a little it but it won't be anything bad. You'll be fine.
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#25 ·
sweet stil not sure tho
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If i understand this correctly a setup like that would not bottleneck on GPU heavy games? (until its limit of power?) i kinda think i saw this the wrong way.....
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