RX Vega Crossfire

[Timothy11]

I have two RX Vega 64 GPU's in my computer with the latest AMD driver but when I go into global settings for games there is no option to turn on crossfire.

Has anyone been able to get crossfire working with these new GPU's?

[Damascus]

Do you have a crossfire bridge?

[tp95112]

1 minute ago, Damascus said:

Do you have a crossfire bridge?

Did AMD go back to using crossfire bridges again?

[Damascus]

6 minutes ago, tp95112 said:

Did AMD go back to using crossfire bridges again?

I dunno, just throwing out possibilities 

[dogetorhue]

 

7 minutes ago, Damascus said:

Do you have a crossfire bridge?

Doesn't look like the vega even has a crossfire finger:

 

[Damascus]

Just now, dogetorhue said:

 

Doesn't look like the vega even has a crossfire finger:

 

 

[Timothy11]

Just took out a pair of rx 480 that were working and they did not need a bridge (or have a finger)

[MadOver]

Dont think Crossfire is even supported on drivers... 

Just get a Custom Vega, will be plenty.

Im waiting for the PowerColor Red Devil to see what they bring

[Timothy11]

3 minutes ago, MadOver said:

Dont think Crossfire is even supported on drivers... 

Just get a Custom Vega, will be plenty.

Im waiting for the PowerColor Red Devil to see what they bring

The Sapphire website lists it as supporting crossfire. (http://www.sapphiretech.com/productdetial.asp?pid=AE163547-6889-4073-BBF6-9DB2C45BB233&lang=eng)

 

I got a two stock ones and plan on water cooling them 1 is not enough for 3440 x 1440

[TheRandomness]

3 minutes ago, Timothy11 said:

The Sapphire website lists it as supporting crossfire. (http://www.sapphiretech.com/productdetial.asp?pid=AE163547-6889-4073-BBF6-9DB2C45BB233&lang=eng)

 

I got a two stock ones and plan on water cooling them 1 is not enough for 3440 x 1440

Do you have a 1000W PSU at least?

32 minutes ago, dogetorhue said:

Doesn't look like the vega even has a crossfire finger:

40 minutes ago, Damascus said:

Do you have a crossfire bridge?

AMD hasn't needed those since the high end 200 series days.

[Timothy11]

I only have a 860W PSU but stress testing with one in is only using 500W that leaves 350W for the second card and they are currently only using the stock air cools at stock speed so they should not need 350W.

 

I do plan on upgrading my PSU before water cooling these cards.

 

attached power test that were run.

RX Vega Crosfire TimeSpy (not working).csv

RX Vega Single TimeSpy.csv

480x Single TimeSpy.csv

480x Crossfire TimeSpy.csv

[TheRandomness]

6 minutes ago, Timothy11 said:

I only have a 860W PSU but stress testing with one in is only using 500W that leaves 350W for the second card and they are currently only using the stock air cools at stock speed so they should not need 350W.

 

I do plan on upgrading my PSU before water cooling these cards.

The Vega 64 has the capability to draw 350W each. So that's 700W already, leaving 160W for the rest of the system. In theory it's fine, but what CPU do you have?

[SlaughterSmurf]

Yeah SLI Vega 64 is pretty risky on an 850W PSU. It probably won't blow it up, but it'll be pretty stressful.

[Timothy11]

6 minutes ago, TheRandomness said:

The Vega 64 has the capability to draw 350W each. So that's 700W already, leaving 160W for the rest of the system. In theory it's fine, but what CPU do you have?

This 3DMark run shows my hardware (http://www.3dmark.com/spy/995522)

CPU: Intel Core i7-5820K
Motherboard: Asus Sabertooth x99

 

I also added my power testing to the previous post.

[Timothy11]

7 minutes ago, SlaughterSmurf said:

Yeah SLI Vega 64 is pretty risky on an 850W PSU. It probably won't blow it up, but it'll be pretty stressful.

I know I plan on upgrading the PSU in the near future.

[SlaughterSmurf]

Just now, Timothy11 said:

I know I plan on upgrading the PSU in the near future.

You just said that before you plan on watercooling them. I wouldn't recommend overclocking them at all before you get a new PSU. 

[Timothy11]

Just now, SlaughterSmurf said:

You just said that before you plan on watercooling them. I wouldn't recommend overclocking them at all before you get a new PSU. 

I will definitely order the PSU before or with the water blocks.

[TheRandomness]

6 minutes ago, Timothy11 said:

This 3DMark run shows my hardware (http://www.3dmark.com/spy/995522)

CPU: Intel Core i7-5820K
Motherboard: Asus Sabertooth x99

 

I also added my power testing to the previous post.

Ah. A 5820k has the potential to draw upwards of 120W, so it's highly possible that the second card just isn't getting enough power, at all.

[Timothy11]

1 minute ago, TheRandomness said:

Ah. A 5820k has the potential to draw upwards of 120W, so it's highly possible that the second card just isn't getting enough power, at all.

That could be the case if I could get it to try and run in crossfire but I am not even getting the option to turn crossfire on in the driver.

[TheRandomness]

Just now, Timothy11 said:

That could be the case if I could get it to try and run in crossfire but I am not even getting the option to turn crossfire on in the driver.

If the card isn't getting enough power to function properly, it wouldn't have the ability to be used in crossfire.

[Timothy11]

Just now, TheRandomness said:

If the card isn't getting enough power to function properly, it wouldn't have the ability to be used in crossfire.

Ok, I will try connecting the second GPU into a second PSU this afternoon when I get home from work, should have a spare 600W or higher PSU around somewhere which will be plenty for just a GPU. (I have done this kind of thing before so I know what to watch out for to avoid blowing things up)

 

Will let you know how  it goes. (Also have a support ticket with Sapphire)

[Damascus]

Try undervolting it and then give CF a shot.

[Timothy11]

1 minute ago, Damascus said:

Try undervolting it and then give CF a shot.

might try that first. I think wattman has a low power profile option.(looks like it only pulls 200W on the low power profile http://www.tomshardware.com/reviews/amd-radeon-rx-vega-64,5173-17.html)

[Timothy11]

12 minutes ago, Damascus said:

Try undervolting it and then give CF a shot.

Changed both cards to low power in wattman but still no crossfire option.

[Damascus]

3 minutes ago, Timothy11 said:

Changed both cards to low power in wattman but still no crossfire option.

Merp, try playing a dx12 game with non heterogeneous mode on.