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Crossfire. Low gpu usage

rabc1690

rabc1690

rabc1690

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Joined
29 Jan 2013
Posts
317
I have 2 vtx3d 7870's in crossfire. Some games can give me well over 100 fps ( sniper elite being one dishonoured gives way up at 90's) while games like hitman only give 35-40at max settings however far cry 3 I struggle to get 1fps at medium settings.

I've also noticed that on a few games in msi afterburner that the gpu usage can be as low as 40-50 usage on both cards.

I'm wondering if I've not setup crossfire properly. I'm using the latest drivers as they were updated couple of hours ago.

I'm running an a10 5800k cpu with 16gb get skill ram
 
What resolution are you playing at? And what speed is the A10 running at?

Either it's the CPU holding it back (it's not really a high end CPU, more like low-mid end), or the game is not properly optimised for multiple GPUs.
 
It's definitely CPU bottleneck no doubt about it. Have seen reviews of the MSI GX60 laptop clearly showing that the A10-4600m was badly bottlenecking the 7970M (which is a little bit slower than the desktop 7870). Now since that your crossfire 7870 would be like around twice as fast as the 7970M, even IF your A10-5800K was twice as fast as the A10-4600K (which it is not by very long miles), it would still bottleneck the CF7870.

To make the most out of the CF7870, you would need at least overclocked Intel i5 or overclocked AMD PD FX63xx/FX83xx with all the cores being used fully.
 
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rabc1690 said:
Yeah but I also have a spare am3+ mobo tho which would mean just a cpu rather than both
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In that case you could just pick up a FX6300. At the moment games don't really benefit beyond 6 cores (and most games not even beyond 4 cores), but Far Cry 3 doesn't scale up to 6 cores:
http://www.techspot.com/review/615-far-cry-3-performance/page6.html

If you look at the frame rate between the FX6300 and FX8350 at 3.50GHz, they are pretty much identical, which proves that FX8350's two extra cores is offering not benefit for the game at all.
 
Yeah the motherboard supports crossfire. Is the fx 6100 a good alternativenoticed they are. Quite cheap on ebay. Does x4 make a difference in crossfire
 
rabc1690 said:
Yeah the motherboard supports crossfire. Is the fx 6100 a good alternativenoticed they are. Quite cheap on ebay. Does x4 make a difference in crossfire
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Don't go for the 6100...that's Bulldozer not Piledriver, and is around 10% slower clock for clock.

As for PCI-E x16 running at x4 the performance hit varys frome game to game. Some games not affected too much by it (8%-20% performance on each card or so), but worst case scenerio it would be as low frame rate as a single card (as well as not as smooth due to being two GPU instead of one having higher latency/micro-shutter etc).
 
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Kewl my board is x16 / x4.what would be. Better choice for 3-4 months until I have enough to build a new computer from scratch. And fx 6300 or a new better board with x8 / x8. Imhappy enoughwith the way games play just the odd couple that ain't the best.
 
Your pc is very out of balance a ton of gpu grunt with a moderate cpu to puah them with. Have you tried running your system with just one 7870? A 5800k and a 7870 should still give great performance without the hassle of running into driver issues. Btw running a 2nd cars on a 4x slot is a big no n.
 
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