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7970 to 7970CF - Scaling pretty badly?

Addicted

Addicted

Addicted

Soldato
Joined
23 Jul 2007
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Worcester
Hey,

So I used to run a 5850 Crossfire setup, until about 2 weeks ago I got an MSI 7970 Lightning (watercooled).

This was going really well, but after seeing the OcUK store opening I had to get one of those Sapphire 7970's.

So now I have CF 7970's @ 1200/1600, however, things aren't all dandy:

1. I've noticed performance only really improve on benchmarks. Some games have actually lowered and have only noticed an increase in Natural Selection 2 (tried the new Need for Speed, Sleeping Dogs, Gmod, StarCraft 2, League of Legends and Planetside 2).

I play some games in Eyefinity as it's quite good if you play the right game (for example Need for Speed), however noticed no performance increase at all - does EyeFinity not support multiple GPU's or something?

2. Microstutter. It's not too bad, but I certainly notice it and see other people suffer from it - is there any way I can reduce/remove it? Looked around but nothing obvious.

Heat/Noise is fine, the main one is watercooled and it keeps any hot air from staying in my 800D, potentially tempted to watercool the Sapphire one but need another radiator to handle the extra heat.

Is this just a problem with game profiles? I'm on 12.10 Beta 6 with CAP 12.10's. Or could it be bottlenecking somewhere?

I run an i7 950 @ 4.2Ghz with 16gb RAM (dual channel at fairly poo timings of 11-11-11-24 (or 27) - also got the RAM at the store opening, before I was at 9-9-9-24 6gb Triple channel.

Any have any suggestions? When I installed the 7970 I did a complete driver clean, but when I installed the second 7970 I didn't bother as it was the same card / crossfire - is this ok?

Not sure what to do, I feel like I'm actually losing any performance increase I should be getting from the second 7970 and in some cases I'm worse off!
 
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What is GPU usage in game for both cards? Use MSI afterburner and the on screen display to keep an eye on it.
 
I'm just checking my motherboard now to see if perhaps 8x+8x is stopping it?

I've got a Asus P6X58D-E Intel X58 so seeing if when in Crossfire it runs 16x+16x, 16x+8x or 8x+8x.

In my very top mini-PCI-E slot I have a sound card also.


JamesM said:
What is GPU usage in game for both cards? Use MSI afterburner and the on screen display to keep an eye on it.
Click to expand...

Varies game to game, benchmarks see the full 100% however most games I don't think do - Planetside is around 60% - I'll have to find out more when I'm home from work!



edit: Just read up now, with both my GPU's how they are they both run at 16x.
 
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8x/8x wouldn't really bottleneck them anyway.

Unless you're running a GPU intensive title like BF3, you are going to find the cards don't scale that well.

Try BF3 in triple screen and report the FPS with and without CF.
 
Disable in CCC.
My cards seem to scale poorly in the smaller titles, they're fine in AAA* games though...other than BL2 that's the only game so far that's "big" where i have next to no scaling.
 
I found this with crossfired 7970's they benched well and one card was fine but two cards never felt smooth even though i was getting high fps :o

I swapped them for 670's which are slower but feel a lot smoother even with 3 cards
 
RadeonPro support dvc a frame limiter which allows you to set let say 60fps and it eliminate what people experience as microstuttering that way. some have tried it and are happy with that program and crossfire.make sure you get the lastest version
 
Ok tried BF3 - they seem to both max 99% usage, and the game is completely smooth in Eyefinity with no microstutter!


Interesting, it would just seem some games aren't optimized at all, and in some cases do worse off :)
 
Mmm it's kind of like that - more that the game has to be able to run both GPU's at max to see the benefit. BF3 is an example of that.

For less intensive GPU games such as Guild Wars 2 for example, it's impossible to remove the CPU bottleneck to allow both cards to max out.

One card can work better in these scenarios.

BF3 64 MP is one of the only games which can be CPU limited and GPU limited in a normal scenario. Dual cards with an overclocked i5 or under? CPU bottleneck. Anything else is GPU limited.

Some games are just CPU limited due to the type of game they are.
 
Yea that's true - are there any other games where CrossFire sees the full benefit?

I also found heat was a slight issue.

I've got a Corsair 800D, with a 360 rad cooling my CPU + Lightning, and the Sapphire is just dispersing heat with the stock cooler.

Playing BF3 for about 10 min and I saw temps go the highest I've ever seen them!

If I was to get another 240 Rad, would this be enough to cool the second card? I'm a little worried that the stock cooler is just throwing heat everywhere, and it's heating everything up!

I kinda wish the 800D was better at more than 1 rad placement without mods :(.
 
Addicted said:
Yea that's true - are there any other games where CrossFire sees the full benefit?

I also found heat was a slight issue.

I've got a Corsair 800D, with a 360 rad cooling my CPU + Lightning, and the Sapphire is just dispersing heat with the stock cooler.

Playing BF3 for about 10 min and I saw temps go the highest I've ever seen them!

If I was to get another 240 Rad, would this be enough to cool the second card? I'm a little worried that the stock cooler is just throwing heat everywhere, and it's heating everything up!

I kinda wish the 800D was better at more than 1 rad placement without mods :(.
Click to expand...

I've got a 360+240 cooling my rig, temps ain't to bad either.
 
In the crossfire tab there is an option to "enable crossfire support for games that have no associated profile". Enabling this made quite a difference for me ?
 
Tonester0011 said:
I've got a 360+240 cooling my rig, temps ain't to bad either.
Click to expand...

Is that for 2x GPUs + CPU?

Do you have an 800D? If so where is the 240, at the bottom (with the famous mod?).

I've got a 140 on the way, hoping to find another 140 or find a way to get another rad in without modification!


MOOGLEYS said:
In the crossfire tab there is an option to "enable crossfire support for games that have no associated profile". Enabling this made quite a difference for me ?
Click to expand...

I'll give that a go, I didn't see that setting :).
 
Addicted said:
I'll give that a go, I didn't see that setting :).
Click to expand...

It's under the crossfire tab on the 12.11 drivers...

Untitled-30.jpg
 
Addicted said:
Is that for 2x GPUs + CPU?

Do you have an 800D? If so where is the 240, at the bottom (with the famous mod?).

I've got a 140 on the way, hoping to find another 140 or find a way to get another rad in without modification!
Click to expand...

Yes mate, 2 7970s and a 3770k.
My case is a Switch 810, so no modding - also the rads are both 60mm.
 
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