So, after getting a little frustrated with my hackintosh endeavour, I am thinking about just sticking to my 2009 Mac Pro for image editing. Afterall Capture One doesn’t seem to give half a shit about CPU performance. So I would be fine throwing a somewhat powerful GPU in there and move on. Currently that is a RX570 ITX from Sapphire and while it does an ok job … there are options.
Now, I do have a Vega 64 reference card which I just rebuilt into it’s original blower fan. But as we all know Vega is on the hungry side and the two mini 6pin PCIe power connectors inside the Mac Pro 4,1 are not meant to provide as much power as two full size 8pin connectors.
Question1: Are there low power BIOS variants available for Vega 64 reference cards?
Question2: Would a Vega 56 BIOS do me any favors in terms of limiting power draw?
Disclaimer: I am aware that this will lower performance, that’s fine. My main concern is to not brick my Mac Pro. I also know about the PSU mod for these machines but I really don’t want to go that route.
Actually this was a lot easier to find than I thought. Techpowerup has all the specs for each BIOS listed out. I’m gonna try this one:
I’d be more worried about Vega in general due to its weird spikes. IIRC even the V56 can spike to over 600W for a millisecond or two, it’ll trip protections on PSUs that can’t account for it, and being an old PSU I suspect the Mac Pro one would have problems with that. Apparently the 5,1 does, IDK how different the PSU in the 4,1 is but I’d assume it’s slightly worse:
I’m not that worried about the PSU itself but more about the traces on the board. On those mac pro machines the additional PCIe power iss supplied through two 6pin that are on the PCB. The PSU should be fine.
I just flashed the 150W BIOS and while a blower card is never quiet, it is a lot more acceptable in terms of noise. The card is now running 800MHz on HBM2, between 1250-1400 on the core and the fan is running around 1600rpm. (running Valley)
I think this should do the trick. I hope I get the two cables tomorrow to test it in the mac.
Yes, the reference cards have a low power bios installed by default if you flick the bios switch, drops it from 300 to 220w.
Maybe, i think their default high power bios is 220w, not sure what the low power bios on them run, or if it is any different.
However, you may be better off/safer offloading the vega for an rx480/580 and letting it run free, you may get similar performance to power constrained vega, and you won’t be messing around with not enough pcie power connectors, etc. And you might get some cash back
I haven’t seen that in my experience; i’d suggest that would be a faulty card and if i saw it i would RMA it.
I had 2x vega 64s running for several months on a 850w power supply doing a bit of mining, crossfire gaming, etc.
I had a bit of a look into it now and in general the Vega 64 has a 200W and a 220W BIOS, Vega 56 has a 165 and 190 I think and Vega 64 liquid can go a bit higher than any air cooled card of course. All of that is just the GPU, the card as a whole draws more power than that.
Like I said, I am now on a 150W BIOS which should result in maybe 200-220W overall. That is a number that should be easy to handle for the PSU / the board traces since there have been Radeon 7970 mac editions and other cards in that power range in the past.
In terms of performance, I think a downclocked Vega is still significantly outperforming any polaris card. Keep in mind we are talking compute here, not gaming performance.
I’ve run Valley for a bit and played WoW for a minute. So far everything is fine. It identifies as attack hel… sorry, as Vega56 but I am pretty sure that it is using the full number of CUs.
I’ve edited this post and marked it as solution so that the important stuff is right on top.
Thanks everyone.
