Crossfire?

[Guest]

Alright so I recently got an r9 390 and there is an r9 290x for 100 and I was wondering if I could cf then and if it would even be worth it? Also how much of a bottleneck would I get from my CPU, I'm guessing alot but I'm planning on upgrading to Ryzen or something later on. Also could my 750 watt PSU power them both?

[Alexcalibur]

I don't think that you can set those up in crossfire..?

[dragoon20005]

290X and 390 can be CrossFired

 

thou your APU will be the major bottleneck here

 

 

also the PSU might not be enough for dual 390/290

[Guest]

Yes you can CF them

 

but not worth it and Power might not enough too

[TheRandomness]

Your PSU would be fine, but I'm not too sure if it'd be worth the performance increase... I mean, scaling tends to be better with crossfire, but you'd be sacrificing a fair amount of the SPs on the 290X to enable crossfire...

Just now, IskanderEXC said:

I don't think that you can set those up in crossfire..?

AMD allows any two (or more) graphics cards with the same GPUs at their core to work in crossfire (290, 290X, 390 and 390X are all Hawaii, and therefore will all work) however, all GPUs will disable parts of themselves to match the lowest count of the bunch. 

[dragoon20005]

2 minutes ago, IskanderEXC said:

I don't think that you can set those up in crossfire..?

dude look here

 

http://www.gigabyte.com/products/product-page.aspx?pid=5715#ov

 

2-way CrossFire™ Multi-graphics support

[Guest]

2 minutes ago, dragoon20005 said:

290X and 390 can be CrossFired

 

thou your APU will be the major bottleneck here

 

 

also the PSU might not be enough for dual 390/290

Would it be worth it? And would my PSU really not be enough? Also I know it'll be a bottleneck.

[dragoon20005]

also to note here as well

 

the second PCI-E slot is x4 speeds

 

so the second GPU will take a 20-30% speed drop

[Guest]

Just now, Abyss Gaming said:

Would it be worth it? And would my PSU really not be enough? Also I know it'll be a bottleneck.

It's also only 100 usd

[dragoon20005]

Just now, Abyss Gaming said:

Would it be worth it? And would my PSU really not be enough? Also I know it'll be a bottleneck.

if you dont OC

 

750W is just enough

 

but dual 290/390 need 850W and above to be comfortable

[dragoon20005]

1 minute ago, Abyss Gaming said:

It's also only 100 usd

get the 290X

 

but install the more powerful GPU which will be the 290X into the first GPU slot

[TheRandomness]

1 minute ago, dragoon20005 said:

also to note here as well

 

the second PCI-E slot is x4 speeds

 

so the second GPU will take a 20-30% speed drop

Not that much, it's about 2-5% less on a PCIe 3.0 x4 slot, and around 5-16% less on a PCIe 2.0 x4 slot. 

1 minute ago, Abyss Gaming said:

Would it be worth it? And would my PSU really not be enough? Also I know it'll be a bottleneck.

Your PSU should be enough. I'm still unsure if it's worth it or not though. 

[dragoon20005]

Just now, TheRandomness said:

Not that much, it's about 2-5% less on a PCIe 3.0 x4 slot, and around 5-16% less on a PCIe 2.0 x4 slot. 

Your PSU should be enough. I'm still unsure if it's worth it or not though. 

that was with a single GPU setup

 

CrossFire setups see a bigger drop in speed and it matters more with high tier GPUs which depends on the PCI-E for data transfer

 

I have seen many CrossFire setups with this configs and user complain getting lesser fps vs full x16/x16 or x8/x8 configs or worse performance vs single GPU.

[arnavvr]

Where did you find a 290X for $100?

[Guest]

6 minutes ago, arnavvr said:

Where did you find a 290X for $100?

eBay

[GitGud]

290X for 100 $ could only mean its beaten to crap in Bitcoin mining and will have short life cycle.

[Guest]

5 hours ago, GitGud said:

290X for 100 $ could only mean its beaten to crap in Bitcoin mining and will have short life cycle.

Well it's a bid so it could go up but so far it hasn't.

[Guest]

6 hours ago, GitGud said:

290X for 100 $ could only mean its beaten to crap in Bitcoin mining and will have short life cycle.

Oh it went up to 130 but only an hour left