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MP09

macrumors newbie
Original poster
Mar 18, 2018
3
0
Just installed a MSI RX 470 ARMOR OC 8GB card in my 2009 Mac Pro. Works right out of the box except for it appears as R9 XXX in About and as far as I can tell it is only operating at PCIe 1.0 x16. I was able to "fix" about by editing the controllers so it says RX 470 now but haven't fixed the graphics acceleration even through kext edits that were needed before 10.12.6 which is what I'm on. Everything I'm finding seems to say it should just work completely so I'm trying to see if anyone else has any more ideas. Thanks in advance!
 

Darmok N Jalad

macrumors 603
Sep 26, 2017
5,422
48,261
Tanagra (not really)
From what I gather, cMPs just don't enable PCIe 2.0 on non-Apple cards. Everything I've seen suggests you have to physically modify the card by removing a certain resistor. It's weird because you get full acceleration in Windows.
 
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rawweb

macrumors 65816
Aug 7, 2015
1,126
943
Just installed a MSI RX 470 ARMOR OC 8GB card in my 2009 Mac Pro. Works right out of the box except for it appears as R9 XXX in About and as far as I can tell it is only operating at PCIe 1.0 x16. I was able to "fix" about by editing the controllers so it says RX 470 now but haven't fixed the graphics acceleration even through kext edits that were needed before 10.12.6 which is what I'm on. Everything I'm finding seems to say it should just work completely so I'm trying to see if anyone else has any more ideas. Thanks in advance!

I'm beta testing High Sierra right now for both my eGPU setup and a RX580 in my cMP. If you can be a little more patient, the cosmetic name (and long running apple display icon bug) should be fixed in the next public release of High Sierra, along with some other enhancements. Not entirely sure on your 470, maybe someone else can chime in.

Screen Shot 2018-03-18 at 8.33.01 PM.png
Screen Shot 2018-03-18 at 8.33.07 PM.png

Regarding PCIe 1, no one has played around with bricking their cards to figure out what resistor will allow the Mac to see at 2.0 speed, if it's even possible. With the cost and availability of cards right now, I wouldn't advise anyone start trying. That said, I thought it was pretty well known that the real world speed difference between the two was negligible.
 

MP09

macrumors newbie
Original poster
Mar 18, 2018
3
0
From what I gather, cMPs just don't enable PCIe 2.0 on non-Apple cards. Everything I've seen suggests you have to physically modify the card by removing a certain resistor. It's weird because you get full acceleration in Windows.

That would be a bummer :/
[doublepost=1521422228][/doublepost]
I'm beta testing High Sierra right now for both my eGPU setup and a RX580 in my cMP. If you can be a little more patient, the cosmetic name (and long running apple display icon bug) should be fixed in the next public release of High Sierra, along with some other enhancements. Not entirely sure on your 470, maybe someone else can chime in.

View attachment 754844
View attachment 754845

Regarding PCIe 1, no one has played around with bricking their cards to figure out what resistor will allow the Mac to see at 2.0 speed, if it's even possible. With the cost and availability of cards right now, I wouldn't advise anyone start trying. That said, I thought it was pretty well known that the real world speed difference between the two was negligible.

I guess I didn't realize the difference was so negligible. Pardon my ignorance. And thanks for the info on High Sierra, I haven't made the jump yet but probably will here in a bit.
 

h9826790

macrumors P6
Apr 3, 2014
16,656
8,587
Hong Kong
That would be a bummer :/
[doublepost=1521422228][/doublepost]

I guess I didn't realize the difference was so negligible. Pardon my ignorance. And thanks for the info on High Sierra, I haven't made the jump yet but probably will here in a bit.

Some gamer put the card in a x8 slot in their PC, that's the time PCIe 2.0 may do something. But on the cMP, unless you put the card in the x4 slot. For x16 slot, PCIe 1.0 is more than enough.

For your info. I ran some tests about how a 7950 perform in a PCIe 2.0 x4 slot. The performance penalty is just 2.4%.

https://forums.macrumors.com/thread...mac-with-2-d700s.1732849/page-5#post-21722712

PCIe 1.0 x16 has double bandwidth available if compare to PCIe 2.0 x4. And a RX470 is just about 70% faster than a 7950 (raw power, in macOS, the actual difference is less than that due to driver optimisation). So, unless you are running out of VRAM. The difference should be virtually zero in most situation.
 
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MP09

macrumors newbie
Original poster
Mar 18, 2018
3
0
Thanks for the info! My mind is at even more ease. Primarily this will be used in FCP so my concern was its overall OpenCL performance would suffer that much which is apparently not the case.
 

Darmok N Jalad

macrumors 603
Sep 26, 2017
5,422
48,261
Tanagra (not really)
And thanks for the info on High Sierra, I haven't made the jump yet but probably will here in a bit.

If you're running an SSD, do yourself a favor and skip the conversion to APFS. This will be especially handy with dual booting Windows. APFS is a bit of an unknown on non-Apple SSDs. It won't hurt them, but using HFS+ just seems to be easier to work with.
 
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rawweb

macrumors 65816
Aug 7, 2015
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943
If you're running an SSD, do yourself a favor and skip the conversion to APFS. This will be especially handy with dual booting Windows. APFS is a bit of an unknown on non-Apple SSDs. It won't hurt them, but using HFS+ just seems to be easier to work with.

I fully agree.

Ran into a bunch of issues at work with one of our cMP's. Needed to clone a SSD (main drive) to a new PCIe SSD. Not an option with APFS...

Aside from some blazing fast transfers, I have yet to see substantial real world performance differences.
 
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