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MP All Models AMD Radeon RX 6800 XT / 6900 XT for macOS?
- Thread starter Xenobius
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Oops, I totally skimmed over that....going to sit in the corner now. ?
Just ordered a pair of the Gigabyte 6800 XTs to replace my two Radeon VIIs (for 10% less than a single W6800 MPX would cost).
Really interested to see how much they can lift my real-time playback in Davinci Resolve. The Radeon VIIs have been brilliant, but I do frequently find myself getting a slightly stuttery 18fps on playback, so if the beefier computing power can lift that up, that'd be terrific.
Really interested to see how much they can lift my real-time playback in Davinci Resolve. The Radeon VIIs have been brilliant, but I do frequently find myself getting a slightly stuttery 18fps on playback, so if the beefier computing power can lift that up, that'd be terrific.
Sorry I meant the 6800x and it’s not arriving for a week. I wanted to see how much mileage I got out of it with 3d modelling software. And maybe swap for a duo if I need more power.
An update on my list above.
It seems that the Sapphire Nitro+ AMD Radeon RX 6800 XT (NON Special Edition) just barely fits
. Dimension (as per manufacturer's website): 310(L)X 134.3(W)X 55.3 (H)mm. So 310mm might be the limit, but... the margin is so small I dont think I would risk it with any other model, its difficult to know what a manufacturer uses as a measurement reference.
CORRECTION: It is the non special edition in the video, which does fit. The Special Edition DOES NOT fit as it is actually 320mm even though the website indicates 310mm.
It seems that the Sapphire Nitro+ AMD Radeon RX 6800 XT (NON Special Edition) just barely fits
CORRECTION: It is the non special edition in the video, which does fit. The Special Edition DOES NOT fit as it is actually 320mm even though the website indicates 310mm.
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Thats the Sapphire in the Mac Pro.
Someone posted this photo earlier in this thread
Attachments
Definitely not the ASROCK RX 6800 XT, it's HUGE. But the 6900XT reference fits really nicely.
I have since moved it to the MPX slot below it, but it worked fine in that slot... originally wanted more airflow around the card for better thermals, but after moving it down, the temps were quite similar...
There are no thermal pads on the backplate so yeah airflow on the back isn't that helpful...
This might already have been answered before, but if someone don't mind:
- When you use a RX6900XT (non-mpx), can you use it alone without any MPX module, and if so do you get a bootscreen etc...?
- If you use it with a MPX module can you still plug your displays in your MPX module (580X in my case) and use the RX6900XT for 3D rendering - let's say a video game for example? Or do you need to plug the display directly in the RX6900XT?
- When you use a RX6900XT (non-mpx), can you use it alone without any MPX module, and if so do you get a bootscreen etc...?
- If you use it with a MPX module can you still plug your displays in your MPX module (580X in my case) and use the RX6900XT for 3D rendering - let's say a video game for example? Or do you need to plug the display directly in the RX6900XT?
In apps that let you choose the GPU like Da Vinchi or Octane x, you don't have to plug the screen to the 6900xt for the software to use it.
In other apps you might need to use a dummy Hdmi plug in the 6900xt, then choose it as your monitor to get the 6900xt preform.
My screens are connected to the 580x and having a Dummy Hdmi is the only way After Effects see the 6900xt.
My two 6800XTs just arrived. Initial tests are showing a big jump in Geekbench Metal scores 310,000 (cumulatively), compared to 198,000 with my two Radeon VIIs.
Blackmagic Raw Speed Test shows a negligible improvement. The Radeon VIIs performing a little faster in decoding lesser quality BM Raw, and the 6800XTs edging ahead in the higher quality versions.
In Davinci, I’m seeing a roughly 9-10% increase in export speeds, and approximately 20% increase in real-time playback framerates.
Blackmagic Raw Speed Test shows a negligible improvement. The Radeon VIIs performing a little faster in decoding lesser quality BM Raw, and the 6800XTs edging ahead in the higher quality versions.
In Davinci, I’m seeing a roughly 9-10% increase in export speeds, and approximately 20% increase in real-time playback framerates.
Very interested to see how these two cards perform. Especially for C4d/Octane. ~€2,300 vs Apple MPX offering is way more attractive at the least.
30k mac pro. Uses Lego support. Lol.
Just shows a lot of us mac pro users just like to tinker with stuff. When i used to use a 5.1 and red rocket x cards I would stick a piece of folder paper between the gpu and red rocket x cards because the tolerance was so tight.
PSA, the Sapphire RX6900XT Nitro+ SE (note the SE) does not fit... Just got one, I didnt know SE was a thing, its advertised as the same length as the other non-se versions pictures in the Mac Pro above, so 310mm, but its in fact 320mm. Fun, so I'm going to have to exchange it ^^
And I guess its confirms that 31cm is the max length that fits.
And I guess its confirms that 31cm is the max length that fits.
Really?
Im waiting to get RX6900XT Nitro+ SE too...
But Sapphire website says 310mm
Should I cancel the order?
Yup website says 310mm, but its really 320mm. I would return it, the non SE version should fit. I'll hopefully find out tomorrow as I should be able to get an exchange - sucks though because it'll probably be a 6800xt since they dont have the 6900xt non-se 
I found one source that had the correct size: https://www.techpowerup.com/gpu-specs/sapphire-nitro-rx-6900-xt-special-edition-oc.b8787
I found one source that had the correct size: https://www.techpowerup.com/gpu-specs/sapphire-nitro-rx-6900-xt-special-edition-oc.b8787
Finally got a working card. I got an exchange for a Gigabyte RX 6900XT Gaming OC, which is 29cm so there's a bit of clearance, which I prefer vs the Sapphire which is just 31cm.
Below are my updated notes as to which card should work, some basic benchmarks and usage notes.
Card has to be <= 310mm to fit. 31cm is the absolute max, keep in mind graphic card manufacturer have no problem miss-labelling by a cm or two.
Benchmarks (all Geekbench 5.1.0 Metal):
Below are my updated notes as to which card should work, some basic benchmarks and usage notes.
Card has to be <= 310mm to fit. 31cm is the absolute max, keep in mind graphic card manufacturer have no problem miss-labelling by a cm or two.
Benchmarks (all Geekbench 5.1.0 Metal):
- MPX 580X (for reference): 47234
- Gigabyte RX6900XT Gaming OC 16GB: 187686 (cabled plugged directly in RX6900XT), 173579 (display plugged in MPX 580X)
- MPX W6800X (Single card): 144910 (https://forums.macrumors.com/thread...s-vs-vega-ii-duo-2x-w5700x-2x-6900xt.2307050/)
- Radeon VII: 58491 (https://barefeats.com/rx-6900-xt-vs-other-gpus-in-imac-pro.html)
- RX 5700 XT: 71203 (https://barefeats.com/rx-6900-xt-vs-other-gpus-in-imac-pro.html)
- Pro Vega 64: 62326 (https://barefeats.com/rx-6900-xt-vs-other-gpus-in-imac-pro.html)
- RX6800 Vanilla card: 141,703 (https://forums.macrumors.com/thread...s.2262295/page-24?post=30121368#post-30121368)
- To use the 6900XT with an app that does not support GPU selection you need to plug the display cable directly in the GPU and run that app on the monitor. That can be done while the Mac Pro is running.
- Apps that support gpu selection work seamlessly, just select the GPU you want to use.
- It looks like there's a ~8% perf advantage if you plug the display cable directly in the RX6900XT. Not too sure why that applies to compute only usages, but GB5's benchmark shows a difference.
- Reference RX 6800 / 6900 XT are 267mm and fit easily.
- Gigabyte Radeon RX 6800 XT & RX 6900 XT GAMING OC 16G: L=286 W=118 H=58 mm. That's what I have. (https://forums.macrumors.com/threads/amd-radeon-rx-6800-xt-6900-xt-for-macos.2262295/post-30169771)
- Sapphire Nitro+ RX 6800/6900XT. Non special edition, that is important, SE does not fit, the non-SE that fits is 310mm which is at the absolute limit of what will fit in. (https://forums.macrumors.com/threads/amd-radeon-rx-6800-xt-6900-xt-for-macos.2262295/post-30163090)
- Gigabyte Radeon RX 6800 XT & RX 6900 XT 16G: L=267 W=120 H=49 mm, should fit
- ASRock RX 6800 Challenger Pro: 305x131x55mm, might just fit
- Sapphire Nitro+ Special Edition RX 6800/6900 XT, advertised as 310mm but is in fact 320mm. The non-se version is in fact 310mm and does fit.
- PowerColor Radeon RX 6800 XT - Red Devil: 320mm*135mm*62 mm: https://forums.macrumors.com/threads/amd-radeon-rx-6800-xt-6900-xt-for-macos.2262295/post-29751958
- ASROCK RX 6800 XT is huge and does not fit. (https://forums.macrumors.com/threads/amd-radeon-rx-6800-xt-6900-xt-for-macos.2262295/post-30164008)
- Asus Tuf Gaming RX 6800/6900 XT: 32 x 14.02 x 5.78 Centimeter.
- AORUS Radeon™ RX 6800 XT AORUS MASTER TYPE C 16G: L=324 W=140 H=60 mm
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^^^^You would gain another slot - 16X (slot 4) if you moved the 6900XT to slot one and the 580X to slot three.
Also, don't forget the RX6800 Vanilla card: 141,703 https://forums.macrumors.com/thread...s.2262295/page-24?post=30121368#post-30121368
Lou
Also, don't forget the RX6800 Vanilla card: 141,703 https://forums.macrumors.com/thread...s.2262295/page-24?post=30121368#post-30121368
Lou
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As pictured, if I have 2x 6800xt or 6900xt installed, and no mpx module, how should I connect the monitor?
I'm going to use two Ultrafine 5Ks. (It only has a Thunderbolt 3 slot, and the 6800 and 6900 only have an HDMI or DP slot.)
1. Do I have no choice but to use a conversion cable?
2. Or is it possible to connect two Gigabyte 6800xt or 6900xt and 580x together to connect the monitor to the main body of the Mac Pro? (In this case, 3 graphics cards are used)
