This Insane AMD Dual GPU from 2021 is Faster than a RX 7900 XTX 

The strange bridge on top of the gpu is the infinity fabric link. That bridge is allowing one gpu to have access to the other gpu memory

the connector on the top edge is for infinity fabric which is similar to Nvidia's NVlink so each core can access the memory of the other core and depending on how the driver is setup it could be doing that transparently making the dual gpu act like a single gpu to programs being run on it. As for the MPX connector the pinout while not publicly fully known it carries video down to the motherboard to be routed to thunderbolt connections on the system and brings thunderbolt pcie lanes into the card to be exposed on the rear.

This is why we are fans. Nobody wants to see the 10,000th PC build with the same 10 parts. The unique and off the wall tinkering is what makes it interesting. PS. I was going to suggest that there was some Bootcamp driver for the card since bootcamp lets you run windows on Mac hardware.

The extra MPX pins are for thunderbolt - you could plug your monitor into one of the thunderbolt ports on the Mac Pro itself and it would still work, because those extra MPX pins can be used to carry the DisplayPort signals back into the motherboard.

You're an absolute legend. I had thought of this back when Apple released their dual GPU cards lol and you actually did it! Madlad!

What I used to do, is modify the driver ini file, with the PCI ID that the card is showing. That usually lets it skip by the check and install the driver, to try it. I've done that lots of times to get drivers working for cards using the same chipset, but different PCI ID. SO if you dig into the driver files, you may be able to do this. The thing with the packaged drivers now, is you usually have to run the installer, then copy the unpacked driver from the temp folder, and then modify the copy, and manually install the driver.

A dual GPU 7900XT that actually worked for gaming would be a monster

I think I have found a worthy successor to my RX Vega obsession. Long live weirdly performant AMD GPUs!

I'd be interested to see a custom block and power metering. I miss dual GPU setups, this was a fun episode!

Hey Roman, You should check out the XFX BC-160 Accelerator. It uses the obscure AMD Navi12 GPU with 8Gb of HBM2. Its similar to the 5700XT but uses HBM2 instead of GDDR6. They were built for Blockchain usage in mining farms. A bit of background: The Navi12 GPU was only supposed to be used in Apple 2020 Macbook Pros. Apparently there was a massive oversupply of the Navi12 GPU and they started using them in Mining accelerators such as the BC-160. The Navi12 features basically ideantical specs to the 5700XT but with HBM2 and a 4096Bit memory bus. I'd be very interested so see a video on the card. I've never seen the Navi12 GPU in the flesh before.

The drivers for this card are not from AMD but rather Apple in their Boot Camp collection. This is the software that Apple bundles to boot and run Windows on their Mac Pro. You got the GPU drivers from it installed but you will also need to the Thunderbolt drivers installed. The HDMI port on the card is fed from one of those Thunderbolt controllers. The MPX controller should also have a few pins for handling interrupts for Thunderbolt hot plug. Not sure if the HDMI functionality requires those pins to be connected. Depending on the task, video memory is indeed additive instead of mirrored across both GPUs. This is due to the on board Infinity Fabric link between the GPUs. Having two of these cards with the Infinity Fabric bridge would enable quad GPU functionality and the ability to pool all the VRAM together depending on the application. The bridge should be attached so that it can properly terminate the Infinity Fabric link. There are four PCIe devices on that card: two GPUs and two Thunderbolt controllers. Conceptually there would be 16 lanes per GPU, 4 lanes to each Thunderbolt controller, 16 lanes to the PCIe connector and presumably 16 lanes to the MPX connector. That'd be 72 lanes in total. What is worth noting is the PCIe bus on the Mac Pro is only PCIe 3.0, though the GPUs support PCIe 4.0. The bridge chip could be limiting things to PCIe 3.0 speeds.

I definitely love me some Dual-GPU cards! I've been wanting to test one of these cards for a while. Glad you were able to get your hands on one!

Honestly Id love to see something like this on pc where the add in cards are these modules which has shrouds fully covering the length of the case as air ducts. While the fans upfront are cooling everything. It just looks so neat and clean.

That was very interesting. Please do make followup with proper power delivery and more tests!

Nice ingenuity getting this to work. I only recently got into doing custom PC mods and I enjoyed seeing someone who knows what they're doing attempting to do something unique. Subscribed!

The MPX connector is used to reroute PCIe to Thunderbolt ports throughout the machine or the Afterburner card.

This was awesome.! Always wanted to see inside this card and see how it done under load! Thanks! Glad you got it going. Would love to see a waterblock for it!

Its always a pleasure to enjoy interesting contents like this. Awesome video as always 🙏🏻🧡

It’s nice to see Techtubers helping each other and not hiding their secrets for themselves 🥰😇💪👍. I enjoyed seeing this gpus pcb ….. what a thing of beauty 🤩

Would love to see more of this card. I think that dual gpu power is underrated by the market, it would be cool to see it coming back to personal builds some day with the new technology that we have in the present.

An amazing video! Never thought I would see one of the last hallmarks of dual gpus running.

Follow-up video is a MUST!!! Very cool stuff!

Amazing video, love when you have unique content like this. Thank you Sir.

Great video. I enjoy this content and look forward to a continuation of this video.

OH WOW!!!! THAT WAS AWESOME!!!!! II can't believe you got it to work!!!! YES!!! MORE TESTING!!!! I just LOVE stuff like this!!! Your videos are always SO MUCH FUN!!!! THANK YOU!!! :D

I think the MPX also has a link to the SMC in the MacPro. Apple stopped implementing GPU metrics in the driver as they communicate directly with the SMC on all other Macs to control power and cooling.

Just gained a sub, keep the great work man!

This was super exciting!!! I love these super exotic PC parts, you're on fire with these new videos, and I can certainly hear your excitement, I wonder what else is next, Micron 9400 Workstation U.2 SSD maybe? I'm ready for anything!

Super interesting video! Thank you for sharing and doing something special with this beautiful dual GPU

Great to see someone test one of these out, I remember being very surprised to see it being released at all during the height of the mining craze.

Aha that's dope! Would love to see a part 2!

Love the different mechanical design of this to what we're used to in the PC space. It's got more elegance to it than the stuff that happens in servers imo (eg the release/removal lever), and reminds me a it of how the gear @CuriousMarc takes apart fits together, but with fewer wire looms!

Would love to see a follow up video, really interesting to see very unique hardware that rarely gets on the spotlight

Insanely interesting thanks ! I hope to see a followup video

The card is correctly stated as 64GB because both GPUs can access all 64GB (although if the memory is in the other GPU the latency is higher, in which _usually_ the CL try using only local memory). What the Infinity Fabric, SLI, Crossfire, NVlink does is to memory map each-other GPU memory space in a high bandwidth dedicated link. It's somewhat limited in consumer grade SLI/Crossfire, but for these Pro series cards, basically any compute language that runs on the card can access full memory, regardless of using a single gpu or all of them.

Looking forward to your watercooling solution and more tests or experiments on this amazing card)

What a super interesting video! Well done, Sir.

Oh man, you gota get this fully working. Love these types of vids.

Awesome video. Fun to watch stuff like this

Hi Roman your videos and enthusiasm is just insane and keeps me watchinng and sometimes even rewatching for zen-purposes during my lunch breaks etc. P.s. whenever someone says the word insane many of us immediately think about your channel haha!

I've been waiting for years for a PCB breakdown of this card!

This is seriously cool! Would love to see a custom water block!

This is the most exciting video I have ever seen in this channel so far.

This video gave me so much enjoyment. Thank you so much. I really appreciate you being such a daredevil lol.

This is a nice look into what graphics cards could be. I don't know why there aren't more like this.

Awesome 😎👍. Would really love to see more.

Great video, and yes, we would like to see the follow up and see other games/apps running on it (if possible)

Wow this was incredible amounts of effort (and patience)

Excellent ! can't wait to see what's next with this card.Exzellent ! Ich kann es kaum erwarten zu sehen, was als nächstes mit dieser Karte kommt

Super neat series looking forward to more

Linux has native support for amd gpus, I wonder if it would’ve worked there out of the box

Amazing piece of tech, I`d love to see more testing with it. Maybe even a custom waterblock?

yes please do a follow up video on this. I would love to see waterblock added to this or some sort of cooler to lock down its max performance. Very impressive

Fascinating, really appreciate this content.

Wonderful video. I would love a follow up video with more in it.

would love to see more on this!

Yes , please make more video's about this card

That is a neat video, I am not surprised there is not much information about the MPX module, getting any sort of electric diagram out of Apple has been the bane of every repair shop in existance. but its cool to see it working. I have also seen videos where the 6800x duo is claimed to be thermal trottling once installed on a Mac Pro and running a productivity suit, looks like the passive cooling and the few fans the mac pro has is not enough.

Awesome video! Would be really fun if you'd manage to put this on a waterblock and attempt some overclocking with it. Also to put it against the 4090 for gaming and productivity work, try raytracing and other features!

Dang this was awesome, I hope you make the water block for it :D

Very interesting! Please let us see more of the card in action.

Amazing card. Loved the video :)

Looking forward to a follow-up!

So epic; the knowledge and skills to make this happen is just awesome. Makes me chuckle, thinking about another vid regarding his 4090 Strix not running at full PCIE x16, people in the comments were like "it could be your motherboard, you should try another motherboard to be sure." COME ON, REALLY? This is der8auer folks.

Please do something crazy with this! Very cool video

very interesting, thanks for this piece

brave man lol love ur vids. greetings for UK

Reminds me of my old gtx 690 dual GPU card ...that was a production pc card but still an absolute pain to get working in 99% of applications and games ... I sold it after just a few weeks it wasn't worth the headaches ...went back to the gtx680 I had as it had more consistent performance in most games.

Definitely would love to see a follow-up video buddy please :)

I would be interested to see more compute oriented workloads. Blender rendering or folding@home for example. This might be a worthwhile deal for a diy setup. Could also be interesting to see if the card can be modified (MPX connector cut off) to fit in a normal motherboard. This thing with a custom watercooling solution would probably be a beast.

i was quite when you do things with that expensive gpu (4090 flashback👀) but i'm glad that you figured out to make the thing works🤗✨

Der8auer you just showed me one of my wishes is actually somewhat achievable! Mad respect to you for spending so much money on something that is pretty much destined to be a showpiece! If I may ask, do you perhaps plan on doing something similar with a Vega II Duo? I believe that is the closest you can get to a full Radeon VII without going for an Instinct MI60. Awesome video!

This is friggin awesome, I would like to see a followup of this.

It’s always interesting to see dual GPU designs. Being Mac just adds extra mystery.

What a beautiful looking GPU

Back when I used a Mac Pro 2006 and a 5000 series AMD GPU (official from Apple), I couldn't install the official AMD Radeon drivers because of the vendor ID on the card was from Apple. My options were to change the vendor ID via a BIOS mod or to install the drivers that are included in the Apple Bootcamp driver. EDIT: I'd love to see a follow-up video of this, especially if you end up making a water block. Would be really cool if you were able to design a custom PCB that the card just slots into and adapts it for use with a normal PC, without needing to solder wires.

Amazing job!

I'd definitely like to see more experiments with this card

thx for the tearing video thisis just what i need it

Zoltar would flip watching your solider skills.

That's the kind of video that very very few people could do for various reasons. Thank you.

Would love to see more on this

This was awesome!

Do more!! I love projects like these. Plz try to figure out out harder

would be great to see more of this card

Thank you for your content DeBauer, for the thermal grizzly and you're snazzy cases plus all the crazy content. You've been on my radar since that weird ad you did for Asus on their benchmarking program. Do you still dub?

Very cool stuff!

Would love to see a follow-up video. Especially water block. Would be interesting to see if crossfire natively works on multiple programs as well as games.

I believe the mpx slot is used to get display signals to all the thunderbolt ports on the MAC chassis, along with other functionality I’m sure.

Der8auers videos are just the best. I really enjoy the genuine never ending curiosity and how Roman, with that produces and shares content that I simply can’t get anywhere else. I LUV IT 👌👍🙏 “Chefs kiss” 😘

It’s so nice to see you all grown up, Jimmy! Where’s Goddard??

Now that's an awesome video.

one of the more interesting pc hardware youtuber, very interesting video

17:15 the MPX connector is there to make the card proprietary. It's even in the name MPX: Mac Pro Extension.

amazing work

The bridge on the GPU is the infinity fabric connection, this allows both GPU's to have access to the memory

Awesome Video! With this technology, AMD could use native x-fire to double up older GPU's and give us some interesting cards to play with. Keep up the good work.

Make the Waterblock ! Want see the full performance and maybe a OC with MPT ? Haha nice video.

Thanks for tearing into this card! Maybe Louis Rossman can get you a pinout for the other connector? Worth a shot.

yeah, i do want to see more of this card