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Dual RX 480s in Mac Pro 5,1 running MacOS (w/ How-to)

h9826790 said:
For AMD card, EFI may not be required for PCIe 2.0, but a resistor mod may be required. However, it's very hard to find out which resistor has to be removed, and hard to know if there is any side effect. For HD7950 / 7970, that's the resistor R17. Once remove that resistor, PCIe 2.0 will be avail in both OSX and Windows regardless if the card has Mac EFI or not. And actually, purely flash the card with Mac EFI won't enable PCIe 2.0 in both OSX and Windows.
Click to expand...

Oh yeah that's right. I've read that before. I have a flashed 7950 and it's stuck at 2.5 GT/s link instead of 5.0. I bought it third party and they did not remove the R17 resistor. Thanks for reminding me!

JoSch said:
But in my experience of several days playing Rise of the Tomb and Doom on one RX480 in a 3,1 with the setting almost all the way up in Full HD resolution, it still gets you the performance you need.
Click to expand...

Hi JoSch, are you using an external power supply with your RX 480 or running it with a 2x6 pin to 8 pin using the internal power supply?
 
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thephased said:
Hi JoSch, are you using an external power supply with your RX 480 or running it with a 2x6 pin to 8 pin using the internal power supply?
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No, I just have the vanilla Sapphire reference card with the 6pin connector. Runs fine on the internal PSU.
Actually, at first I got the OC version from Sapphire (never trust the user answers on Amazon), but since it had the 8pin connector (and I wanted a 5770 as boot screen provider), I sent it back.
 
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Here are my results after editing the AMDRadeonX4100.kext and the AMD9500Controller.kext as per the (tonymac) instructions. I do have 36 units active but my score seems a bit low. Maybe its because i'm running 2x Samsung 4k screens at 1440p. My card is a MSI rx480 gaming X 4gb.
 

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I'm getting 64 cu's with the three patch strings. I don't know why.
Heaven benchmark (821) is the same. Secondlife feels the same.
I have a xfx rx470 (RX-470P4LFB6). My luxmark score is 11358 after these three patch strings. I never did a before luxmark test.

Screen Shot 2016-12-17 at 7.56.49 AM.png
 
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mavericks7913 said:
in MacOS 10.12.2?
Click to expand...

Mine still in MacOS 10.12.1

Number Curtain said:
I'm getting 64 cu's with the three patch strings. I don't know why.
Heaven benchmark (821) is the same. Secondlife feels the same.
I have a xfx rx470 (RX-470P4LFB6). My luxmark score is 11358 after these three patch strings. I never did a before luxmark test.

View attachment 678495
Click to expand...
First String
48 B8 04 00 00 00 01 00 00 00 48 89 43 54 C7 43 7C 12 00 00 00

This will give you 36.



THIRD STRING
Should be searching : E8 09 85 FE FF BE 48 01 00 00 4C 89 F7 instead

Replace By: E8 73 02 01 00 BE 48 01 00 00 4C 89 F7


First String
48 B8 04 00 00 00 01 00 00 00 48 89 43 54 C7 43 7C 20 00 00 00

Will give you 64.
 
I just ran a LuxMark test with a single XFX RX 480 under MaxOS 10.12.2.

Is this an OK score?
 

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frompast said:
Mine still in MacOS 10.12.1


First String
48 B8 04 00 00 00 01 00 00 00 48 89 43 54 C7 43 7C 12 00 00 00

This will give you 36.



THIRD STRING
Should be searching : E8 09 85 FE FF BE 48 01 00 00 4C 89 F7 instead

Replace By: E8 73 02 01 00 BE 48 01 00 00 4C 89 F7


First String
48 B8 04 00 00 00 01 00 00 00 48 89 43 54 C7 43 7C 20 00 00 00

Will give you 64.
Click to expand...

I followed this as well (I did not do the 2nd step and remove the CU limit): https://www.tonymacx86.com/threads/enable-all-cores-r9-fury-cards.209892/#post-1393445

Luxmark is reading 18 CUs. Scores are within 4 digits, not 5 as they should be. I wonder why people are getting different reported CUs with the RX 480...

Valley is choking running under 10 FPS. Is anyone having problems with these CU modifications?

edit: well this mod really messed something up on my system. Sierra doesn't even shutdown. I've tried everything to get the performance back to normal. Reverted the changes in the kexts back to just RX 480 support in Info.plist, Extracted AMD9500Controller.kext, AMDRadeonX4100.kext from the 10.12.2 combo update to try to see if using those would work. Reset PRAM. Making sure SIP is disabled. Unplugged system. Re-installed Sierra 10.12.2. Same thing. I'll have to start fresh. The screen turns black when I launch Photoshop and the fans run full speed...

There's no problem with my external SATA boot drive running 10.12.2. Valley, Luxmark, and Steam games perform fine.

Maybe take caution if you try this mod?
 
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The # of CU's reported in Luxmark doesn't seem to make a difference on the score. Shouldn't full 36 CU's from RX 480 put the score around 24,000?

Is this simply a cosmetic workaround?
 
namethisfile said:
The # of CU's reported in Luxmark doesn't seem to make a difference on the score. Shouldn't full 36 CU's from RX 480 put the score around 24,000?

Is this simply a cosmetic workaround?
Click to expand...

If you compare to Windows result, obviously it cannot achieve 24000. However, it also doesn't shows a linear relationship as well (score vs CU count). Still very hard to understand what's happening behind the scenes.
 
The mod should increase the OpenCL performance by ~30%-50% (depending on benchmark) for RX 480 and even more than that for Fiji-based GPUs.

As for the question why the score doesn't improve linearly: I guess the answer is somewhere in the architecture of the GPU itself and/or power management.
 
I just tried the HEX string edit by cdrhoek on Tonymac: https://www.tonymacx86.com/threads/enable-all-cores-r9-fury-cards.209892/#post-1393445 on a XFX RX480 8GB Reference Cooler.
I followed along with his initial post and edited the string he mentioned using iHex. When I rebooted acceleration was turned off so I ran the Kext Utility, rebooted and acceleration was back online. Overal I'm happy with the results, so far.
Before the Hex string edit I was getting a 11413 score in LuxMark. Now, my LuxMark score is 14199. That's nowhere near the 20k mark other users are reporting on Tonymac but it's a nice upgrade overall. Render times in Cinema 4D are also a lot quicker and LuxMark is also reporting 64 Compute unites. Don't know what that means as the card manufacturer states it has 36.
Anyone else getting results around the 20k mark?
EDIT: Running on macOS: 10.12.2
 

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The hack you've used (and the results you're referring to) were ment for R9 Nano / Fury / Fury X users, not RX 480. Your score looks perfectly, although the amount of CUs is wrong.
 
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Fl0r!an said:
The hack you've used (and the results you're referring to) were ment for R9 Nano / Fury / Fury X users, not RX 480. Your score looks perfectly, although the amount of CUs is wrong.
Click to expand...
LOL! I totally missed that. I assumed it would also work because it was about editing the 4100 kext. The same kext you edit to get the RX480 working. I'm surprised I even got 'better' results with the HEX edits. At this point, I'll try anything to get RX480 to it's maximum potential.
 
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