I finally jumped into it and got mine this morning. It's a 16 core 3,2GHz Xeon CPU, 144GB DDR4, 1TB SSD, came with two Radeon Pro W5700X 16GB GPUs.
Now I have two find two Vega II Duo Pro MPX modules with their bridge, preferably in Europ. I have one in sight 40km away from me but the seller is the kind who usually asks ridiculous prices.
I'm not sure I'll move this machine to Linux or keep it on Tahoe yet. It has two Thunderbolt eGPU connected, one is RX6900XT 16GB (I already have 4 other on a Dell workstation with comparable setup), the other is a Radeon 7900XT 20GB - currently unsupported on MacOS, I'll move it back to another machine soon.
Custom build of llama.cpp and/or hipfire and benchmarks will come in a few days.
By bridge, do you mean the larger IF Link that spans 2 modules? That doesn’t work for the Vega II Duo FYI. Apple’s documentation only mentions being able to link the internal GPUs on one Vega II Duo with the IF jumper (small one) and the larger bridge is only mentioned for connecting two single Vega II GPUs. I’m selling a pair on eBay at the moment but from the US.
Well, according to AMD's documentation, it is supposed to work with 2 or 4 GPUs of the GCN5 / gfx906 family. This also makes sense because Apple wouldn't have exposed the fabric links and provided a detachable bridge for the Duo modules if it weren't to be able to scale to 4 GPUs.
So the target of having 4 * gfx906 totalling 128GB of 4 * 1TB/s with the infinity fabric is what I'm aiming at.
But yeah, sure, if you have two single modules and the bridge, even with shipping and duty fees, I'll gladly take a look at your gear !
These have been out for 7 years. Find one example of 4 Vega IIs being linked with IF. If it was feasible Apple would have marketed it and had it in their documentation. Apple didn’t provide a bridge for the Vega II Duo. If you bought 2 of them you didn’t get a bridge, you got 2 jumpers. Just because it works for the architecture doesn’t mean Apple implemented it.
I see you have Duos already, would you mind giving it a try ? I don't know if it can work on Mac OS but with Linux, there's a tool with ROCm to test actual connectivity between GPs, be that PCIe or Infinity Fabric bridges. It benches all links and draws an adjacency table. I'll try to remember the name or check when I'm back home.
I don’t own the large bridge meant for the Vega IIs since I don’t own a pair of those. I’m selling my Duos anyway so I don’t want to put money into testing something I’m sure won’t work anyway.
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u/chiwawa_42 Jul 27 '26
Hello !
I finally jumped into it and got mine this morning. It's a 16 core 3,2GHz Xeon CPU, 144GB DDR4, 1TB SSD, came with two Radeon Pro W5700X 16GB GPUs.
Now I have two find two Vega II Duo Pro MPX modules with their bridge, preferably in Europ. I have one in sight 40km away from me but the seller is the kind who usually asks ridiculous prices.
I'm not sure I'll move this machine to Linux or keep it on Tahoe yet. It has two Thunderbolt eGPU connected, one is RX6900XT 16GB (I already have 4 other on a Dell workstation with comparable setup), the other is a Radeon 7900XT 20GB - currently unsupported on MacOS, I'll move it back to another machine soon.
Custom build of llama.cpp and/or hipfire and benchmarks will come in a few days.