R9 280x Crossfire problem - Need Help

[Juliogol]

Hi folks.

 

I've got a problem here that is driving me crazy and after a week+ of researching and reading still can't get to the solution.

 

I have a Xfx R9 280x and recently I bought another one to do a Crossfire.

 

Thing is that I am not getting better performance than before with only one card. When checking the GPU usage on games like BF 3 or BF4, I get 40-60% on both GPU's of usage. FPS is alomst the same than before, when running a single card.

 

I play at 1080p (on a 1440p monitor for now, vsync off) and I get around 80-110 max FPS with Crossfire enabled, on medium settings. And with a single card, I am around 75-100 FPS.

 

With the two XFX R9 280x, shouldn't I be able to get at least 100 FPS stable in 1080p, medium settings? And why on earth is my gpu usage only on 40-50% on crossfire and 80-90% on a single GPU? Is the fact that my monitor is only 60hz refresh rate holding back the GPU's even if i have Vsync off?

 

My specs

 

Core I5 2500k at 3.7 GHZ

Gigabyte H67 h67m-ud2h-b3 motherboard

12 GB RAM

120 GB SSD

 

Tried already

 

Updating drivers

Disabling ULPS

Disabling Frame Pacing

Using Mantle (runs a bit better, but nothing specatcular)

Fresh OS install.

 

Please help me out here! 

 

Thanks!!!

[Timopomer]

overclock them? (i dont like multi GPU set ups,i much rather have one beast than 2 minions )

[dragoon20005]

Hi folks.

 

I've got a problem here that is driving me crazy and after a week+ of researching and reading still can't get to the solution.

 

I have a Xfx R9 280x and recently I bought another one to do a Crossfire.

 

Thing is that I am not getting better performance than before with only one card. When checking the GPU usage on games like BF 3 or BF4, I get 40-60% on both GPU's of usage. FPS is alomst the same than before, when running a single card.

 

I play at 1080p (on a 1440p monitor for now, vsync off) and I get around 80-110 max FPS with Crossfire enabled, on medium settings. And with a single card, I am around 75-100 FPS.

 

With the two XFX R9 280x, shouldn't I be able to get at least 100 FPS stable in 1080p, medium settings? And why on earth is my gpu usage only on 40-50% on crossfire and 80-90% on a single GPU? Is the fact that my monitor is only 60hz refresh rate holding back the GPU's even if i have Vsync off?

 

My specs

 

Core I5 2500k at 3.7 GHZ

Gigabyte H67 h67m-ud2h-b3 motherboard

12 GB RAM

120 GB SSD

 

Tried already

 

Updating drivers

Disabling ULPS

Disabling Frame Pacing

Using Mantle (runs a bit better, but nothing specatcular)

Fresh OS install.

 

Please help me out here! 

 

Thanks!!!

ah ha i found your problem

 

you mobo PCI-E 

 

http://www.gigabyte.sg/products/product-page.aspx?pid=3769#sp

1. 1 x PCI Express x16 slot, running at x16 (PCIEX16)

   * For optimum performance, if only one PCI Express graphics card is to be installed, be sure to install it in the PCIEX16 slot.

2. 1 x PCI Express x16 slot, running at x4 (PCIEX4)
3. 2 x PCI Express x1 slots

   (All PCI Express slots conform to PCI Express 2.0 standard.)

the second PCI-E slot is running at 4X speeds and since it is Gen 2 PCI-E

 

that even slower!!!

 

so your second 280X is getting choked

[Juliogol]

ah ha i found your problem

 

you mobo PCI-E 

 

http://www.gigabyte.sg/products/product-page.aspx?pid=3769#sp

1. 1 x PCI Express x16 slot, running at x16 (PCIEX16)

   * For optimum performance, if only one PCI Express graphics card is to be installed, be sure to install it in the PCIEX16 slot.

2. 1 x PCI Express x16 slot, running at x4 (PCIEX4)
3. 2 x PCI Express x1 slots

   (All PCI Express slots conform to PCI Express 2.0 standard.)

the second PCI-E slot is running at 4X speeds and since it is Gen 2 PCI-E

 

that even slower!!!

 

so your second 280X is getting choked

 

Thought of that too! But will that have a big impact on FPS? Some say it does but others say not so much, that's what's confuses me

[dragoon20005]

Thought of that too! But will that have a big impact on FPS? Some say it does but others say not so much, that's what's confuses me

it does

 

esp when it gen 2 PCI-E

 

bandwidth reduces by half when it is split

 

if it was a low end GPU not so bad but in the case of the 280X it just like a poor guy trying to suck bubble tea pearls using a normal drink straw

[Juliogol]

it does

 

esp when it gen 2 PCI-E

 

bandwidth reduces by half when it is split

 

if it was a low end GPU not so bad but in the case of the 280X it just like a poor guy trying to suck bubble tea pearls using a normal drink straw

 

Never thought of it being so important in terms of FPS in game. Will have to try, because now it's giving me 35-45% GPU usage and aprox 70-100 FPS in crossfire, 1080p and medium settings. That can't be right... With this setup I should be able to get 100fps stable right?

[dragoon20005]

Never thought of it being so important in terms of FPS in game. Will have to try, because now it's giving me 35-45% GPU usage and aprox 70-100 FPS in crossfire, 1080p and medium settings. That can't be right... With this setup I should be able to get 100fps stable right?

you should be able to get much higher fps

 

280X in X-Fire is around 10% faster than a single 290X

 

so my suggestion

 

go for a new CPU and board which supports PCI-E 3.0

 

a i5 4670K and Z87