So is the answer switching from Sapphire RX 580 Nitro+ to Pulse? Because I bought the Nitro only because pulse was nowhere to be found where I'm from
The Nitro+ come with dual ROM, you can flash one of them with the PULSE ROM, it should work. But if not, you can always flash it back to the native ROM (make sure you have at least 2 backup of the original ROM BEFORE you attempt any flash).
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h9826790 @owbp - Thanks for Your replies!
What precisely do You mean by
share loading or
using sata power PROPERLY - other than connecting sata cables to PCIe - what woud be the correct way to do this?
By Pixlas mod do You mean going through all the hassle described in this link?
https://forums.macrumors.com/threads/pixlas-4-1-mac-pro-mod.1859652/
I was really hoping RX 580 would be a hassle free solution
I can't even boot into Widows now - the Mac freezes during the Bood Drive selection at startup when I choose Windows - OSX starts normally.
I can't boot into windows now so I can't check the amperage on windows.
I was able to check it on mac os though,
If I read it right (screenshots included) my 8 pin connection draws about 96W (8A) during Unigine Valley test and much less from the 6pin and Pcie slot. I never experienced hard shutdowns with this card on OSX, although I'm still testing. Still the situation can be very different in Windows and/or when I put much more stress on the card in Mac OS.
View attachment 738018 View attachment 738019
96W is a bad sign, not because it's more then 75W, but it hit the display ceiling. 96W usually is not the actual power draw, but just the display limit. The GPU can draw more than 120W but iStat can still display 96W.
Think in this way.
The PCIe slot only feeding 3.74A (~45W), the PCIe boost B only 1.36A (~17W).
If the PCIe boost A only providing 7.99A (96W), then your card is just drawing 96+45+17 = 158W.
Way way below the 235W TDP.
Even the native ROM most likely come with a -20% power setting. 235W x 80% = 188W. That still 30W above your 158W. If we add that 30W to the 96W. Then it will become 126W. High enough to shut down the Mac (the cut off point is about 120W).
But of course, since your card may not really drawing 188W at that moment (due to Unigine Benchmark is not that demanding in MacOS), therefore, your actual power draw may be just tiny bit below the shut down protection limit. But in Windows, depends on your setting, that -20% may be override by the driver and become -0%. In this case, you card can draw up to 235W. And DirectX in Windows can easily push your card to this 235W limit. Which also means, much easier to hard shut down in Windows.
If you want to do a stress test in MacOS. The best way is the run Furmark. It's hiding inside and app called "GPUTest". From your power draw, I expect it will shutdown the Mac if you run it for something like 15min.
However, also from your power draw, there is a good news that you don't need to flash your card, or perform and mod. Just use 2 different cables will fix the issue.
Cable A - dual mini 6pin -> single 8pin (or single 6pin, it's up to you)
Cable B - FEMALE single 8pin (or single 6, depends on cable A) - > dual 6+2pin.
I use this combination to power my GTX1080Ti, it has higher TDP than your RX580, and also come with 6+8pin config. my outcome is as follow.
As you can see, there still some difference between the PCIe Boost A and B, but the difference is small. And this is what I mean "share the loading". Fully utilise both mini 6pin together to power the 6+8 pin, but not heavily rely on only one of them to drive the 8pin.
From the above graph, you can also see Unigine is not that demanding if compare to Furmark. Also, you can see that 96W display limit (in my case, 97w). Clearly, the green line always go above the blue line by a bit, but once it hit the 96W limit, it goes flat strangely.
You can select boot drive during boot? You have another GPU in your Mac?
