crossfire at x4 even worth it?

[Something Else]

im contemplating getting another 7850 for crossfire but my board only supports the normal x16 and the other lane is x4 so is it even worth getting another gpu or should i upgrade my board then crossfire?

 

[Kaapstad]

im contemplating getting another 7850 for crossfire but my board only supports the normal x16 and the other lane is x4 so is it even worth getting another gpu or should i upgrade my board then crossfire?

Your card supports PCIe 2 so a second card running @ X4 rather than X16 could take a bit of a performance hit. It would be the same as running @PCIe 1 X8 which is not good.

I do not know how much difference it makes for the card running @ X4 not being the primary card in the CrossfireX setup.

If you post the details of the rest of your system someone who knows a bit more than me could give a more accurate and detailed answer.

 

[Tonester0011]

He's using dual GPU so the 8x slot should be the numbers you're looking at for 4x single GPU (correct me if i'm wrong)

 

[Orcvader]

What motherboard do you have? x16/x4 crossfire will take quite a performance hit.

 

[Rusty0611]

It won't take THAT much a performance hit - don't overstate it.

It's a hit undoubtedly but the more pressing issue is the increased perception of micro-stutter when running 16x/4x which according to some reviews is worse than at 8x/8x.

 

[Surveyor]

What motherboard do you have? x16/x4 crossfire will take quite a performance hit.

I think he has a Gigabyte Z68AP-D3 with an i5-2500K.

Jamsames, this should hopefully give you a rough idea:Does CrossFire Work At x16/x4?

 

[Something Else]

I think he has a Gigabyte Z68AP-D3 with an i5-2500K.

Jamsames, this should hopefully give you a rough idea:Does CrossFire Work At x16/x4?

yea i have that board and cpu,

im going to be changing the board to somthing that supports x8 in the future i just wondered if there was any point to buying the extra 7850 now and using it for a bit till i got a new board. guess ill wait

 

[Rusty0611]

I think he has a Gigabyte Z68AP-D3 with an i5-2500K.

Jamsames, this should hopefully give you a rough idea:Does CrossFire Work At x16/x4?

That's what I was looking for .

@OP

A 10% loss is still only 10% of whatever scaling Crossfire offers.

i.e.

8x/8x
1 card 50 FPS;
2 cards 100 FPS

16x/4x
1 card 50 FPS
2 cards 95 FPS

Hardly the end of the world.

I'm not saying it's good and I wouldn't recommend it but the performance hit isn't TOO big.

i.e

 

[Something Else]

so it wont be a massive improvement due to the limitations but it wont make the fps in game any worse correct?

 

[Rusty0611]

Check my example above. If you get 100% crossfire scaling (i.e. a doubling of FPS) then you'll get say 10% reduction of that scaling.

You'll still get the benefits of it. It'll just be bottlenecked slightly by the PCI-E lane. Not ideal. But in my example you'd lose 5 FPS over an 8x/8x set up. Not ideal but not the end of the world especially as you're upgrading your motherboard anyway.

 

[LtMatt]

Check my example above. If you get 100% crossfire scaling (i.e. a doubling of FPS) then you'll get say 10% reduction of that scaling.

You'll still get the benefits of it. It'll just be bottlenecked slightly by the PCI-E lane. Not ideal. But in my example you'd lose 5 FPS over an 8x/8x set up. Not ideal but not the end of the world especially as you're upgrading your motherboard anyway.

I'm currently using xfire on a p8p67 stock gen 3.0 board. x16 x4.

Running smooth here and i score about 100-200 points less than someone using a x8 x8 board according to the unigine benchmark. I don't think its a huge problem to be honest, its not optimal performance but the hit is not noticeable.

As for microstutter i get a small amount on battlefield 3 ONLY and that is solved by using vsync.

EDIT

If anyone here is running an x8 x8 setup id be happy to compare performance over unigine and match settings to see how much the difference is.