MP All Models AMD Radeon RX 6800 XT / 6900 XT for macOS?

[rondocap]

And more from Bare Feats:

Pro W6800 versus RX 6000 series in Mac Pro 2019

real world speed test results for performance minded Macintosh users

barefeats.com

Given the specs, not too surprising.

Lou

Very interesting - only advantage here are cases where the extra VRAM can be utilized. It seems like at least in most video editing workflows, it doesn't necessary need 32GB of Vram.

I tested the 16GB 6900XT vs the Vega II 32GB, and VRAM rarely was an issue in video, maybe only in BRAW 12k to 4444 XQ or similar

 

[randy85]

Update: the Gigabyte 6800 XT arrived and managed to get it installed. It took me a few goes trying different slots because... I guess I'm the type of user Apple had in mind when designing the MPX modules ?

However, the slot utility now says everything is optimal and it's showing up in Resolve, so mission accomplished.

Of course I would've preferred to keep it all MPX modules, but I have to say that for around £1100 (including the aux power cables), this is a pretty nice upgrade.

 

[Grumply]

Does anyone know if it would be possible to use PCIe extension cables to retain access to the PCIe ports that these overly large GPUs would block?

 

[johnnymcc]

Update: the Gigabyte 6800 XT arrived and managed to get it installed. It took me a few goes trying different slots because... I guess I'm the type of user Apple had in mind when designing the MPX modules ?

However, the slot utility now says everything is optimal and it's showing up in Resolve, so mission accomplished.

Of course I would've preferred to keep it all MPX modules, but I have to say that for around £1100 (including the aux power cables), this is a pretty nice upgrade.

Nice! I've been playing with mine in either slot 3 or 4. I read somewhere that GPUs should really be installed in either slot 1 or 3. Read here: https://softron.zendesk.com/hc/en-u...e-cards-in-your-2019-Mac-Pro?mobile_site=true

The problem I have is when my 6900 XT is flush and snug to the 5700 MPX module when installed in slot 3. It seems like the GPU will get too hot with no airflow under the card. However, when I was monitoring temps in Windows 10 while playing the game Control (really intense graphics), there was marginal differences in temps between slot 3 & 4. Based on the above article, I find this interesting:

About slots 1 to 4​

Slots 1 to 4 are quite specific as these can host the 2 MPX modules. When the 2 MPX modules are connected, you won't be able to use any of these slots. And they are quite specific:

• As explained above, slots 1 & 3 each have 16 lanes of PCIe 3.0 directly linked to the CPU. Indeed, as these slots are meant to host the graphics cards, you don't want them to have to share the bandwidth with other devices.
• Slots 2 and 4 share 8 lanes of PCIe 3.0 with the MPX connector. These 2 slots are used to provide PCIe bandwidth to the Thunderbolt ports that are available on the card. If you connect a "simple" graphics card only to slot 1 or 3, slots 2 and 4 should be available to provide 8 lanes of PCIe 3.0, that will be part of the 2 pools.

And here are a few recommendations:

• Graphics cards should always be connected in slot 1 or 3.
• Other 16-lanes cards (such as the Afterburner), can be connected to the remaining 16-lanes slots (1, 3, 4 or 5). But if you have only one graphics card in slot 1, we recommend using slot 3. Indeed this slot won't count in the pool allocation, and thus will leave you more bandwidth for the remaining slots.
• 8 lanes and 4 lanes cards, prefer to use slots 6 or 7. Most AJA, Blackmagic-Design and M|Family cards should work fine in these slots. But most of these cards are also compatible with 16 lanes slots, so it should be fine to use it in the 16 lanes slots. Check the tech specs of the cards to verify.

 

[randy85]

Nice! I've been playing with mine in either slot 3 or 4. I read somewhere that GPUs should really be installed in either slot 1 or 3. Read here: https://softron.zendesk.com/hc/en-u...e-cards-in-your-2019-Mac-Pro?mobile_site=true

The problem I have is when my 6900 XT is flush and snug to the 5700 MPX module when installed in slot 3. It seems like the GPU will get too hot with no airflow under the card. However, when I was monitoring temps in Windows 10 while playing the game Control (really intense graphics), there was marginal differences in temps between slot 3 & 4. Based on the above article, I find this interesting:

About slots 1 to 4​

Slots 1 to 4 are quite specific as these can host the 2 MPX modules. When the 2 MPX modules are connected, you won't be able to use any of these slots. And they are quite specific:

• As explained above, slots 1 & 3 each have 16 lanes of PCIe 3.0 directly linked to the CPU. Indeed, as these slots are meant to host the graphics cards, you don't want them to have to share the bandwidth with other devices.
• Slots 2 and 4 share 8 lanes of PCIe 3.0 with the MPX connector. These 2 slots are used to provide PCIe bandwidth to the Thunderbolt ports that are available on the card. If you connect a "simple" graphics card only to slot 1 or 3, slots 2 and 4 should be available to provide 8 lanes of PCIe 3.0, that will be part of the 2 pools.

And here are a few recommendations:

• Graphics cards should always be connected in slot 1 or 3.
• Other 16-lanes cards (such as the Afterburner), can be connected to the remaining 16-lanes slots (1, 3, 4 or 5). But if you have only one graphics card in slot 1, we recommend using slot 3. Indeed this slot won't count in the pool allocation, and thus will leave you more bandwidth for the remaining slots.
• 8 lanes and 4 lanes cards, prefer to use slots 6 or 7. Most AJA, Blackmagic-Design and M|Family cards should work fine in these slots. But most of these cards are also compatible with 16 lanes slots, so it should be fine to use it in the 16 lanes slots. Check the tech specs of the cards to verify.

Interesting... I did try it in slot 3, however I got a message telling me to move my Afterburner from slot 6 into slot 4 (which was covered up by the the 6800 XT). It also did seem very close for airflow as you mentioned, so decided to move it in the config I have now.

Perhaps I will try 6800 XT in slot 3 and Afterburner in slot 5 as your breakdown there suggests...

 

[joevt]

Does anyone know if it would be possible to use PCIe extension cables to retain access to the PCIe ports that these overly large GPUs would block?

All you need is a riser cable that is low profile enough to fit under the GPU and a place to put the other card. I don't know if such riser cables exist. Theres a bunch of options at http://www.adt.link/product.html but I don't know if they are low profile enough (or if you could modify them to make them lower profile).

slots 2 and 4 should be available to provide 8 lanes of PCIe 3.0

Slot 4 can have 16 lanes if you use a non-MPX card in slot 3 as shown in the post above. https://forums.macrumors.com/threads/amd-radeon-rx-6800-xt-6900-xt-for-macos.2262295/post-30132785

The Radeon Pro 580X MPX and W5500X modules are 2 slots wide and don't have Thunderbolt controllers so they won't use the 8 lanes of slot 2 (if in slot 1) or the 16 lanes of slot 4 (if in slot 3).

I wonder if slot 4 switches to 8 lanes if a MPX module with Thunderbolt ports is in slot 3 (since only 8 lanes is required for 2 Thunderbolt controllers)? You would need a riser cable to fit under the MPX module to get access to slot 4 since all MPX modules with Thunderbolt are 4 slots wide.

 

[rondocap]

I may be a bit funny, as I have two reference 6900xt that I had in there before - and they do perform really well, noise levels are fine too - but I REALLY like the MPX modules. Maybe it's a bit OCD, but they just fit and feel better, lol. So I threw the dual Vega ii mpx back in there with the infinity fabric.

How can you not love these beautiful MPX modules, slot right in perfectly! It makes the Mac Pro unique

The 6900XT are faster than the Vega II for most video work in general, but not always a huge difference. I would think a W6800 would be even less of a difference - so hopefully they bring at least a W6900x with 32GB of VRAM or another flagship GPU like the Vega ii duo level to really take it to the next level.

 

[johnnymcc]

I may be a bit funny, as I have two reference 6900xt that I had in there before - and they do perform really well, noise levels are fine too - but I REALLY like the MPX modules. Maybe it's a bit OCD, but they just fit and feel better, lol. So I threw the dual Vega ii mpx back in there with the infinity fabric.

How can you not love these beautiful MPX modules, slot right in perfectly! It makes the Mac Pro unique

The 6900XT are faster than the Vega II for most video work in general, but not always a huge difference. I would think a W6800 would be even less of a difference - so hopefully they bring at least a W6900x with 32GB of VRAM or another flagship GPU like the Vega ii duo level to really take it to the next level.

Nice, yea the MPX modules are def more svelte & refined than standards GPUs. I like also having the latest AMD reference card in there for Windows 10 gaming really (the only reason) and full usage of the latest AMD adrenaline drivers. It's nice to have both honestly, the refined MPX module and the 6900 XT!

 

[randy85]

I may be a bit funny, as I have two reference 6900xt that I had in there before - and they do perform really well, noise levels are fine too - but I REALLY like the MPX modules. Maybe it's a bit OCD, but they just fit and feel better, lol. So I threw the dual Vega ii mpx back in there with the infinity fabric.

How can you not love these beautiful MPX modules, slot right in perfectly! It makes the Mac Pro unique

The 6900XT are faster than the Vega II for most video work in general, but not always a huge difference. I would think a W6800 would be even less of a difference - so hopefully they bring at least a W6900x with 32GB of VRAM or another flagship GPU like the Vega ii duo level to really take it to the next level.

I know what you mean. I keep telling myself it doesn't matter cus it's all inside the case, but I would have preferred an MPX module if it was available just for the slickness.

Interestingly, I noticed that there is a W6900X showing up on the Geekbench charts - not sure if it's legit or not.

I just ran the Metal benchmark on mine though and got 162,576 (6800 XT) vs 75,451 (W5700X) so I'm happy.

 

[diamond.g]

I know what you mean. I keep telling myself it doesn't matter cus it's all inside the case, but I would have preferred an MPX module if it was available just for the slickness.

Interestingly, I noticed that there is a W6900X showing up on the Geekbench charts - not sure if it's legit or not.

I just ran the Metal benchmark on mine though and got 162,576 (6800 XT) vs 75,451 (W5700X) so I'm happy.

Your score is as high as the 6900XT they list, which would make the whole chart sus, no?

 

[blazerunner]

I may be a bit funny, as I have two reference 6900xt that I had in there before - and they do perform really well, noise levels are fine too - but I REALLY like the MPX modules. Maybe it's a bit OCD, but they just fit and feel better, lol. So I threw the dual Vega ii mpx back in there with the infinity fabric.

How can you not love these beautiful MPX modules, slot right in perfectly! It makes the Mac Pro unique

The 6900XT are faster than the Vega II for most video work in general, but not always a huge difference. I would think a W6800 would be even less of a difference - so hopefully they bring at least a W6900x with 32GB of VRAM or another flagship GPU like the Vega ii duo level to really take it to the next level.

Why? The case is closed, you never see it. Why bother putting in a more expensive worse performing component?

 

[randy85]

Your score is as high as the 6900XT they list, which would make the whole chart sus, no?

No idea. I assume it's due to other variables on people's systems. It's useful though to compare my two cards at least.

 

[diamond.g]

No idea. I assume it's due to other variables on people's systems. It's useful though to compare my two cards at least.

Do you have a reference card?

 

[brandon_macpro]

Anyone having any luck picking up 6900xt reference card in USA. I want to get 2

 

[johnnymcc]

Anyone having any luck picking up 6900xt reference card in USA. I want to get 2

I got mine on FB Marketplace - but paid too much!

 

[brandon_macpro]

I got mine on FB Marketplace - but paid too much!

Dang, Crypto is keeping them propped up well above what they should actually be. hopefully, that changes but Idk if I can wait for w6900x to release in Dec.

 

[diamond.g]

Dang, Crypto is keeping them propped up well above what they should actually be. hopefully, that changes but Idk if I can wait for w6900x to release in Dec.

That would be cool if true but 6900Xt's are not good with crypto mining (especially compared to the 6800xt).

 

[johnnymcc]

That would be cool if true but 6900Xt's are not good with crypto mining (especially compared to the 6800xt).

So why is the 6800xt better for crypto?

 

[rondocap]

Why? The case is closed, you never see it. Why bother putting in a more expensive worse performing component?

I open the case all the time.

And it does have benefits - sometimes the 64GB of VRAM is better than the 32GB with two GPUs, and the extra thunderbolt is useful too.

And the performance difference isn't huge in most cases - but who knows if they may be optimized better when the W6800x comes out and have better drivers.

 

[rondocap]

So why is the 6800xt better for crypto?

The 6800, 6800xt, and 6900xt all get between 52-62 Mh/s on average, which isn't too good considering their cost, compared to like an Nvidia 3070 which is more efficient.

Oddly enough, the Vega II does get a nice 80 mh/s, but it comes at increased power draw too. W5700x gets around 49 Mh/s for those curious.

 

[diamond.g]

The 6800, 6800xt, and 6900xt all get between 52-62 Mh/s on average, which isn't too good considering their cost, compared to like an Nvidia 3070 which is more efficient.

Oddly enough, the Vega II does get a nice 80 mh/s, but it comes at increased power draw too. W5700x gets around 49 Mh/s for those curious.

This. Memory bandwidth matters for crypto and the infinity cache doesn’t help.

 

[brandon_macpro]

AMD Radeon™ PRO W6000X Series Graphics Card

www.amd.com

our prayers have been answered lets goooo.

 

[bsbeamer]

Apple Introduces New High-End Graphics Options for Mac Pro

Apple today began offering new high-end graphics upgrade options for both the tower and rack versions of the Mac Pro desktop computer. This comes on...

www.macrumors.com

 

[brandon_macpro]

Now I looked at the prices. Ill stick to finding a 6900xt in the wild sometime soon. At those prices I could build a pc with 2 3090's inside smh.

 

[johnnymcc]

Now I looked at the prices. Ill stick to finding a 6900xt in the wild sometime soon. At those prices I could build a pc with 2 3090's inside smh.

Seriously. Those prices are crazy. Just buy a stock 6900 XT reference card as I did!