Mac Pro with 2 different GPUs?

[Steve Delahoyde]

I ordered a new Mac Pro, which I’ve had for a couple of months now. I spent the money on getting more cores and ram, and just kept with the stock 580x GPU. I’ve since ordered a single Vega II MPX card from Apple, now that is available and it’ll arrive tomorrow. Is there any sense to leaving the 580x in there along with the new one? Any benefit or issues? Thanks!

 

[Jeff Kilgroe]

No real benefit to keeping the 580x GPU. In theory, you could use it as your display GPU and reserve the Vega II for computational purposes only. Unfortunately that tends to confuse many apps and is often more hassle than it's worth, also nowhere near as good as a display GPU. Using your compute GPU as a display GPU has minimal impact in most situations. I don't know if you could sell the 580x or if you just keep it boxed up for the day you retire the Mac Pro or perhaps demote it to server duty and then sell the Vega II separately.

 

[Steve Delahoyde]

Good to know! Thanks very much!

 

[Johnny S]

If you remove the 580X, you also remove displayport support for the built-in Thunderbolt 3 ports. This may not just affect video, it may render those ports inoperable. Please report back what you find.

 

[Jeff Kilgroe]

If you remove the 580X, you also remove displayport support for the built-in Thunderbolt 3 ports. This may not just affect video, it may render those ports inoperable. Please report back what you find.

You don’t lose DisplayPort support. The 580X card has 4 DisplayPort internal connectors to supply onboard TB3 ports. The Pro Vega II card offers a couple TB3 ports itself as well as supplies two internal DisplayPort connectors for supplying the other onboard TB3 ports. The Pro Vega II Duo card gives four internal DP ports. Not connecting DP input for TB3 ports does not render the ports inoperable.

 

[Tom Sefton]

I have the Vega Pro II and a Radeon VII. It flies in Resolve and FCPX. Premiere is utter rubbish.

Without the Radeon VII, performance drops considerably.

 

[Steve Delahoyde]

I got the card installed and took out the 580X and had no trouble anywhere, Display Ports or anything else.

Tom, what's the benefit of adding a Radeon VII on top of the Vega? Can Resolve run both? And is it just an off-the-shelf Radeon?

Forgive my ignorance with these things. GPUs aren't my strong suit (nor, probably, is much else for that matter).

 

[Johnny S]

You don’t lose DisplayPort support. The 580X card has 4 DisplayPort internal connectors to supply onboard TB3 ports. The Pro Vega II card offers a couple TB3 ports itself as well as supplies two internal DisplayPort connectors for supplying the other onboard TB3 ports. The Pro Vega II Duo card gives four internal DP ports. Not connecting DP input for TB3 ports does not render the ports inoperable.

It seems you are confirming what I already said. I didn't say you lose Displayport support, I said by removing the MPX module cards (580x / Pro Vega II / etc) you lose them for the built-in TB3 ports. I'm glad to hear that with just a RADEON VII the TB3 ports still work otherwise as expected.

 

[Steve Delahoyde]

It seems you are confirming what I already said. I didn't say you lose Displayport support, I said by removing the MPX module cards (580x / Pro Vega II / etc) you lose them for the built-in TB3 ports. I'm glad to hear that with just a RADEON VII the TB3 ports still work otherwise as expected.

Oh, no, I was swapping out the 580 MXP and putting in a Pro Vega MPX. So Apple-approved all around. I think that got lost along the way.

 

[Steve Delahoyde]

I have the Vega Pro II and a Radeon VII. It flies in Resolve and FCPX. Premiere is utter rubbish.

Without the Radeon VII, performance drops considerably.

I'd love to hear, Tom, what's the benefit of adding a Radeon VII on top of the Vega? Can Resolve run both? And is it just an off-the-shelf Radeon?

 

[Tom Sefton]

It's an off the shelf Radeon VII, and it adds at least 8fps when de-noising with resolve, which for our VR workflow is really helpful. When I get time, I'll upload some benchmarks for the performance with and without, but if you look at barefeats.com, he did some tests with some 8K anamorphic footage and a host of different GPUs to show the actual gains from each card. From memory, adding the Radeon VII on top of the Vega Pro II, it reduced the encode from red to ProRes by half (and this was before the most recent resolve/metal/red release)