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MP 1,1-5,1 Using Vega 56 in MP 5,1 - questions

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macman4789

macrumors 6502
Original poster
Jul 12, 2007
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Hey guys,

I've done some research on the Vega 56 being the highest card you can use without modifying the MP 5,1’s PSU and need some advice. I’ve managed to get hold of the Sapphire Pulse Vega 56 version (see pics) and it has a wattage of 180w power draw in the website. It has two 8 pin connectors in the middle of the card and I was wondering which cables are suitable for it. Is it as simple as using two 6 mini pin to 8 pin cables plugged into the main board? That should give me 75w from PCI port and two 75w sources from each cable?

Ideally I don’t want to modify the PSU but this should be sufficient power for this card without worrying about power issues? I wondered whether anyone else had a Vega 56 without modifying the PSU and successfully ran it in a MP 5,1?

Many thanks.

F3A910BE-B667-462F-850C-8E45B4248200.jpeg
 
macman4789 said:
Hey guys,

I've done some research on the Vega 56 being the highest card you can use without modifying the MP 5,1’s PSU and need some advice. I’ve managed to get hold of the Sapphire Pulse Vega 56 version (see pics) and it has a wattage of 180w power draw in the website. It has two 8 pin connectors in the middle of the card and I was wondering which cables are suitable for it. Is it as simple as using two 6 mini pin to 8 pin cables plugged into the main board? That should give me 75w from PCI port and two 75w sources from each cable?

Ideally I don’t want to modify the PSU but this should be sufficient power for this card without worrying about power issues? I wondered whether anyone else had a Vega 56 without modifying the PSU and successfully ran it in a MP 5,1?

Many thanks.

View attachment 937093
Click to expand...
First, 75W from the PCIe slot should not be considered, most cards only draw 30 to 40W from the PCIe slot. The only modern GPU that uses 75W, sometimes over 90W, is the RX 480 reference model (just one PCIe 6-pin input).

Tom's Hardware tests show that a reference Vega 56 can draw up to 329W at full power usage, like when running Furmark.

If you not going to do a Pixla's mod, at least use an eVGA PowerLink.
 
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tsialex said:
First, 75W from the PCIe slot should not be considered, most cards only draw 30 to 40W from the PCIe slot. The only modern GPU that uses 75W, sometimes over 90W, is the RX 480 reference model (just one PCIe 6-pin input).

Tom's Hardware tests show that a reference Vega 56 can draw up to 329W at full power usage, like when running Furmark.

If you not going to do a Pixla's mod, at least use an eVGA PowerLink.
Click to expand...

I’ve looked into an eVGA power link but got told that it would not fit on this card? Would you agree? I’m not very knowledgeable about their main function and sort of disregarded it when I got told it wouldn’t fit. Would it matter if I’m not going to game on it much and thus probably not really maximise the wattage?
[automerge]1595618181[/automerge]
KeesMacPro said:
I doubt this is a real life number..

I think Pixlas mod is the savest way to enjoy your Vega 56.
Click to expand...
I see. That’s swayed things as a lot of what I’ve read has said Vega 64 and above yes for pixlas mod but Vega 56 should be fine hence why I got it. Is it easy to setup?
 
macman4789 said:
I’ve looked into an eVGA power link but got told that it would not fit on this card? Would you agree? I’m not very knowledgeable about their main function and sort of disregarded it when I got told it wouldn’t fit. Would it matter if I’m not going to game on it much and thus probably not really maximise the wattage?
Click to expand...
If your card is one that have the NANO PCB design, eVGA PowerLink won't really fit, then you will need to do a Pixla's mod if you use anything that can fully use the GPU like FCP X.

Some people use cables to connect from the output of the PowerLink to the card inputs, a way to postpone doing the Pixla's mod.
[automerge]1595618457[/automerge]
forums.macrumors.com

Pixlas 4.1 Mac Pro mod

I'm creating a thread for my 4.1-->5.1 mod to keep everything in one place. I will document my upgrade to X5690, PCIe SSD (Apple SSUBX) and PSU mod to allow for two modern gfx cards using only the internal PSU. I have gotten my Mac Pro now (2x 2.26GHz) 4.1 from 2009. It had one Nvidia 120GT...
forums.macrumors.com forums.macrumors.com
 
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macman4789 said:
I’ve looked into an eVGA power link but got told that it would not fit on this card? Would you agree? I’m not very knowledgeable about their main function and sort of disregarded it when I got told it wouldn’t fit. Would it matter if I’m not going to game on it much and thus probably not really maximise the wattage?
[automerge]1595618181[/automerge]

I see. That’s swayed things as a lot of what I’ve read has said Vega 64 and above yes for pixlas mod but Vega 56 should be fine hence why I got it. Is it easy to setup?
Click to expand...
If you won't stress the card, then why get such a powerful card?

If you will stress the card, even not gaming, but video editing, the peak power draw can over 300W for Vega. That 180W typical power draw has a lot of assumptions. e.g. That's the numbers in Windows. And assume you install the Radeon Software, which will set the PowerTune to 0%.

In macOS, PowerTune read directly from the ROM, which is 50% for PULSE Vega56.

Therefore, even if the card really only draw ~180W with PowerTune at 0%, you can expect the card can draw ~270W in macOS (180W x 150%). In fact, the Power Consumption of this card on the Sapphire website is 280W, not 180W.


Screenshot 2020-07-25 at 3.25.33 AM.png
 
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tsialex said:
If your card is one that have the NANO PCB design, eVGA PowerLink won't really fit, then you will need to do a Pixla's mod if you use anything that can fully use the GPU like FCP X.

Some people use cables to connect from the output of the PowerLink to the card inputs, a way to postpone doing the Pixla's mod.
[automerge]1595618457[/automerge]
forums.macrumors.com

Pixlas 4.1 Mac Pro mod

I'm creating a thread for my 4.1-->5.1 mod to keep everything in one place. I will document my upgrade to X5690, PCIe SSD (Apple SSUBX) and PSU mod to allow for two modern gfx cards using only the internal PSU. I have gotten my Mac Pro now (2x 2.26GHz) 4.1 from 2009. It had one Nvidia 120GT...
forums.macrumors.com forums.macrumors.com
Click to expand...
If it didn’t fit, would you only see the power link as a temporary solution? I think ok just scared of doing the pixlas mod 😆
[automerge]1595620040[/automerge]
h9826790 said:
If you won't stress the card, then why get such a powerful card?

If you will stress the card, even not gaming, but video editing, the peak power draw can over 300W for Vega. That 180W typical power draw has a lot of assumptions. e.g. That's the numbers in Windows. And assume you install the Radeon Software, which will set the PowerTune to 0%.

In macOS, PowerTune read directly from the ROM, which is 50% for PULSE Vega56.

Therefore, even if the card really only draw ~180W with PowerTune at 0%, you can expect the card can draw ~270W in macOS (180W x 150%). In fact, the Power Consumption of this card on the Sapphire website is 280W, not 180W.


View attachment 937113
Click to expand...
No I am going to utilise it more for video editing which I know draws a lot of power, I’m just trying to evaluate from people on here who are more knowledgeable than me whether the pixlas mod is absolutely necessary or not or whether I could just use the two mini 6 pin to 8 pin cables.

If I was going to have power issues with just the two cables, what sort of issues would I have? Random shut downs, that sort of thing?

thanks for your time
 
macman4789 said:
I see. That’s swayed things as a lot of what I’ve read has said Vega 64 and above yes for pixlas mod but Vega 56 should be fine hence why I got it. Is it easy to setup?
Click to expand...

I would take my time to read the PIXLAS thread ,there are YT videos e.g. by house of moth ,if i remember well, before doing the mod.
With basic electronics skills one can do it.

The advantage of PIXLAS is to avoid current draw for the GPU through the logic board.
AFAIK when the MP was designed there were no GPUs drawing >300Watts.
Normally current for the GPU goes : PSU>LogicBoard>mini 6pin>GPU
with Pixlas it goes: PSU>GPU.
THe PSU is rated for 980 Watts so this is fine.

macman4789 said:
what sort of issues would I have? Random shut downs, that sort of thing?
Click to expand...

Too high current draw (peaks) via the LoBo will result in shut down.
IMHO it will definitely not improve the expected lifetime of the LoBo (capacitors etc.).
 
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tsialex said:
First, 75W from the PCIe slot should not be considered, most cards only draw 30 to 40W from the PCIe slot. The only modern GPU that uses 75W, sometimes over 90W, is the RX 480 reference model (just one PCIe 6-pin input).

Tom's Hardware tests show that a reference Vega 56 can draw up to 329W at full power usage, like when running Furmark.

If you not going to do a Pixla's mod, at least use an eVGA PowerLink.
Click to expand...


329W is pretty generous as consumption, I just run Luxmark and took a screen shot of the consumption while the test was running (OUCH), I have Pixlas mod and eVGA as well, I'm kind of far from the 329W on my VEGA 56.
 

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Flocarino said:
329W is pretty generous as consumption, I just run Luxmark and took a screen shot of the consumption while the test was running (OUCH), I have Pixlas mod and eVGA as well, I'm kind of far from the 329W on my VEGA 56.
Click to expand...

macOS with a PowerTune of 50%, will get that 310.6 power consumption, see that the instantaneous peak is 377W! Believe or not, it's real consumption measured with top notch instrumentation from Rohde&Schwarz. Take a look at the methodology and equipment used by Tom's hardware reviews, the site UX is poop with all the reviews being split into 30~40 pages, but the technical side of it is still sound.

www.tomshardware.com

AMD Radeon RX Vega 56 8GB Review

Radeon RX Vega 56 should be hitting store shelves with 3584 Stream processors and 8GB of HBM2. Should you scramble to snag yours or shop for something else?
www.tomshardware.com www.tomshardware.com
 
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I personally wouldn't use a Vega GPU in a 5,1 without doing the 'pixlas mod.' I think the best GPU for the 5,1 is the Pulse RX 580 with vbios modded to "Apple edition." WX 7100 would be good too if you want a slim card. And of course there are a number of older GPUs that will work well such as a Tahiti (e.g. HD 7950/R9 280) or Nvidia Kepler (GTX 680, K6000, etc).
 
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tsialex said:
fDZGWfCRwynjCxzLygi6LR-650-80.png


macOS with a PowerTune of 50%, will get that 310.6 power consumption, see that the instantaneous peak is 377W! Believe or not, it's real consumption measured with top notch instrumentation from Rohde&Schwarz. Take a look at the methodology and equipment used by Tom's hardware reviews, the site UX is poop with all the reviews being split into 30~40 pages, but the technical side of it is still sound.

www.tomshardware.com

AMD Radeon RX Vega 56 8GB Review

Radeon RX Vega 56 should be hitting store shelves with 3584 Stream processors and 8GB of HBM2. Should you scramble to snag yours or shop for something else?
www.tomshardware.com www.tomshardware.com
Click to expand...
So according to this you posted, I’d be fine using the two mini 6 to 8 pin cables when web browsing at just over 50watts of power until I wait for the Pixlas Mod cable/kit to arrive? I.e. stay away from heavy usage until then?
 
macman4789 said:
So according to this you posted, I’d be fine using the two mini 6 to 8 pin cables when web browsing at just over 50watts of power until I wait for the Pixlas Mod cable/kit to arrive? I.e. stay away from heavy usage until then?
Click to expand...
Modern GPUs can have insane levels of instantaneous power consumption, without a PowerLink to balance the power draw between the two PCIe AUX BOOST connectors you probably will have safety shutdowns.

Honestly, backplanes are becoming more scarce lately and costlier every day. I wouldn't risk mine.
 
macman4789 said:
So according to this you posted, I’d be fine using the two mini 6 to 8 pin cables when web browsing at just over 50watts of power until I wait for the Pixlas Mod cable/kit to arrive? I.e. stay away from heavy usage until then?
Click to expand...

No. If you only want to use the two built in receptacles/power cables, then an RX580 is about the max you can go.

Do not use either Vega card (56 or 64) without the pixels mod. Period. It's really not that hard to do this modification. I just did it 2 weeks ago to run my Vega 64. It was my first time ever doing it and it was a success.

And in my opinion, if you're gonna go Vega, spring an extra 30+ bucks and get the 64 over the 56, since you have to do the pixels mod to run either one.
 
Ok thanks for all your advice guys. Think I’ll take it and order the Pixlas mod kit today. 👍
 
Can I just ask if Apple lists on their site the list of metal capable cards for Mojave in the Mac Pro 5,1 and the Vega 56 is one of them including the 64, is that not some sort of confirmation that it is supported? I presume they are not endorsing modifying the PSU using the Pixlas Mod to enable compatibility? I’m not disagreeing with anyone on here but just querying what Apple’s stance is to safely run the card in a Mac Pro?

Install macOS 10.14 Mojave on Mac Pro (Mid 2010) and Mac Pro (Mid 2012) - Apple Support

Learn how to prepare your Mac Pro (Mid 2010) or Mac Pro (Mid 2012) for macOS Mojave.
support.apple.com support.apple.com
 
They're just saying it WILL work and IS supported. How the end user GETS it to work (power supply) is up to the user.

Apple would rather you scrap the machine and buy one of their new ones, honestly.
 
macman4789 said:
Yeah I get that but surely when Apple write this article they’re not relying on people doing the Pixlas Mod to power the cards Vega 56 and above on the list...
Click to expand...

A guideline or recommendation published by Apple is not a Law.
If you look around on this Forum, you can see what is possible with these beautiful machines without breaking them.
The people sharing their achievements here, are guided by experience and know-how, searching for new frontiers I suppose...
I guess we can only speculate about the reasons why Apple supports things or not....
 
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