MP 6,1 How to the Dual GPU work in the 6,1 Mac pro?

[ek9max]

Just a looking for a quick overview on how the Dual GPU work int he 6,1 Mac pros.

I picked up a 2013 for ***** and giggles and have never had a computer with dual GPU.

Do they just share the computing tasks equally? 1 powers half the screen while the other powers the other half? One does all teh work and teh other picks up the slack when needed? Only 1 works unless using a program optomized to use both?

Thanks in advance.

 

[mattspace]

Just a looking for a quick overview on how the Dual GPU work int he 6,1 Mac pros.

I picked up a 2013 for ***** and giggles and have never had a computer with dual GPU.

Do they just share the computing tasks equally? 1 powers half the screen while the other powers the other half? One does all teh work and teh other picks up the slack when needed? Only 1 works unless using a program optomized to use both?

Thanks in advance.

IIRC 1 is responsible for all display drawing, the other is a compute accelerator for apps that support multi-gpu.

 

[Flint Ironstag]

Yeah, normally GPU0 handles display duty, and GPU1 computes. Some apps like Hashcat utilize both.

 

[ek9max]

IIRC 1 is responsible for all display drawing, the other is a compute accelerator for apps that support multi-gpu.

So in most cases just the one does all the work and the other sits idle?

 

[mattspace]

So in most cases just the one does all the work and the other sits idle?

Assuming the system doesn't assign non-display duties to the compute card preferentially, the other side effect is that the maximum supported displays for the system are those of only one of the cards.

 

[Flint Ironstag]

So in most cases just the one does all the work and the other sits idle?

Exactly this. Apple is chasing the fluid user interface that never bogs down. Anything that the CPU can offload to coprocessors will be.

 

[MisterAndrew]

Yeah one for display and one for compute if the app supports it. Same goes for dual GPUs in the 7,1 or any other Mac I guess. Crossfire is possible in Windows.

I haven’t tested it myself with two monitors, but the diagram shows all 6 DP ports are connected to graphics board B and the HDMI port is connected to graphics board A. However, the HDMI port only supports 30Hz at 4K rather than 60Hz like the DP ports.

 

[ek9max]

So basically there is no need for 2 cards in these things?

 

[DeltaMac]

It's a dual-GPU configuration.
Why would you conclude that means the system will function without both of the cards.
Which card will you remove? (I'll sit here with my popcorn

 

[Flint Ironstag]

There is a thread here where the guy is reverse engineering the MP 6,1 motherboard. He ran it without the compute GPU for a while. Not sure if he attempted it with both removed. Wouldn’t surprise me if he got it to work. Some clever folks around here.

 

[mattspace]

So basically there is no need for 2 cards in these things?

Yes, under macOS it's effectively a single-GPU system, with a GPU-based compute card.

 

[ek9max]

It's a dual-GPU configuration.
Why would you conclude that means the system will function without both of the cards.
Which card will you remove? (I'll sit here with my popcorn

How's your popcorn? Salty I'm sure.