Crossfire 290 and 390

[skry365]

If I have the 390 in already can I just drop in the 290 in the next fastest PCI slot? I dont see why id have to mess with drivers.....???

 

[bob4933]

As long as your psu can handle it....

 

[skry365]

Yeah I was thinking about that as well. I probably shouldn't risk it with a 750 watt Platinum then eh?

 

[Seabee]

If I have the 390 in already can I just drop in the 290 in the next fastest PCI slot? I dont see why id have to mess with drivers.....???

I asked the same question a few months back and was told CF won't work with different generation GPUs. Being the 290 still needs a bridge to CF and the 390 does not, I am leaning toward that information being correct.

-Seabee

 

[ATMINSIDE]

What's your whole system?

They are the same GPU, basically, so they can be run in Crossfire.

 

[cdawall]

I asked the same question a few months back and was told CF won't work with different generation GPUs. Being the 290 still needs a bridge to CF and the 390 does not, I am leaning toward that information being correct.

-Seabee

290 doesn't need a xfire connector. They xfire fine (I have done it). They are the same generation GPU with more ram slapped on.

 

[ATMINSIDE]

290 doesn't need a xfire connector. They xfire fine (I have done it). They are the same generation GPU with more ram slapped on.

Bingo.

It is worth noting though, you won't be able to utilize all the vRAM on the 390 when in Crossfire.

 

[cdawall]

Bingo.

It is worth noting though, you won't be able to utilize all the vRAM on the 390 when in Crossfire.

I would be curious what happens with DX12 multiGPU instead of xfire.

 

[ATMINSIDE]

I would be curious what happens with DX12 multiGPU instead of xfire.

It will depend on game developer support.

 

[cdawall]

It will depend on game developer support.

DX12 in itself allows for ram sharing between the cards however. I am curious if it will see 8GB or 12GB. That part shouldn't depend on game/dev.

 

[ATMINSIDE]

DX12 in itself allows for ram sharing between the cards however. I am curious if it will see 8GB or 12GB. That part shouldn't depend on game/dev.

It will depend on the devs, just like SLI and Crossfire currently depend on the devs.
When it happens, and is supported, it will act as 12GB in this instance.

 

[MaddMutt]

What's your whole system?

They are the same GPU, basically, so they can be run in Crossfire.

If you want to be technical, the 390 is an upgrade to the 290.
Do you remember (back in the days) when you could run 2 ATI/AMD cards. All they had to be was from the same Series 38xx, 48xx, 58xx. If you paired a faster card with a slower one, the faster one would drop to the slower ones speed.

With this new Cross Fire Over PCIe, that NO LONGER WORKS. YOU have to MATCH CARDS from the same GPU SERIES to get Cross Fire to work. I tried to CF a 290 and a 290x, the system refused to see the second card.

 

[ATMINSIDE]

If you want to be technical, the 390 is an upgrade to the 290.
Do you remember (back in the days) when you could run 2 ATI/AMD cards. All they had to be was from the same Series 38xx, 48xx, 58xx. If you paired a faster card with a slower one, the faster one would drop to the slower ones speed.

With this new Cross Fire Over PCIe, that NO LONGER WORKS. YOU have to MATCH CARDS from the same GPU SERIES to get Cross Fire to work. I tried to CF a 290 and a 290x, the system refused to see the second card.

The 290 and 290X are not the same card. AMD does not list compatibility for those two together.
It isn't CrossfireX over PCIe causing the issue you had.

 

[cdawall]

I run a 290 and 290X in crossfire at work it sees both cards fine.

 

[Janus67]

If you want to be technical, the 390 is an upgrade to the 290.
Do you remember (back in the days) when you could run 2 ATI/AMD cards. All they had to be was from the same Series 38xx, 48xx, 58xx. If you paired a faster card with a slower one, the faster one would drop to the slower ones speed.

With this new Cross Fire Over PCIe, that NO LONGER WORKS. YOU have to MATCH CARDS from the same GPU SERIES to get Cross Fire to work. I tried to CF a 290 and a 290x, the system refused to see the second card.

290+290x works in crossfire. I had a quad setup briefly that was mixed and it worked. (During the time I was mining)

 

[ATMINSIDE]

Well, news to me, for some reason I wasn't aware it worked.

 

[cdawall]

With amd they have to be the same core and they will crossfire number of shades doesn't matter. That's how the entire hybrid crossfire idea works.

 

[bob4933]

Well, news to me, for some reason I wasn't aware it worked.

AMD is far far far more loose on xfire than nvidia is with SLI.


The 390 is as similar to the 290, as the 290 is the 290x. There are changes all around, but they all have slight differences. They can all be crossfired together.

Same as an r9 380x and an r9 285 can be crossfired. Same base GCN core is all thats required to crossfire.

 

[ATMINSIDE]

AMD is far far far more loose on xfire than nvidia is with SLI.


The 390 is as similar to the 290, as the 290 is the 290x. There are changes all around, but they all have slight differences. They can all be crossfired together.

Same as an r9 380x and an r9 285 can be crossfired. Same base GCN core is all thats required to crossfire.

I knew they did it for a lot of models, but I didn't think it applied to the 290/290X for some reason.

 

[MaddMutt]

290+290x works in crossfire. I had a quad setup briefly that was mixed and it worked. (During the time I was mining)

I had no problem getting the cards to work under GPUPI or Folding At Home