MP 1,1-5,1 VEGA 56 with eVGA powerlink

[Mylo3000]

Hi all,
I've recently bought a Sapphire Pulse Vega 56 for my mac pro 5,1 and want to install without currently doing the pixlas mod ( i plan on doing this at a later date).
I've read lots of things about power draw and shutdowns etc and have been advised to buy the eVGA powerlink to balance the power.
My question is, is this ok and also how do i connect it.
Is it 2 x mini 6 pin to 2 x 8 pin into the powerlink which is connected to the card, or an alternative like dual mini 6 pin to 1x 8 pin. I'm confused on what leads i need. I read somewhere here (can't find the post now) that someone was also using sata cables but i don't really understand what that means. Any help would be appreciated.

 

[zedex]

Despite my thinking / general agreement that PIXLAS is necessary (highly advisable?) for VEGA GPUs. I'm not sure I believe that anymore. Here is a picture of what you are proposing tested over a 36 hour period last weekend.

I took a cMP 5.1 (what I call my "test unit" because I diagnosed that an RX 480 with poor power management had permanently damaged my PSU) and decided to run my AMD Sapphire Radeon RX Vega 64 (8GB HBM) Liquid Cooled WITH an EVGA Powerlink on this "disposable" Mac Pro over the weekend and find out if the much documented fears are warranted.

Result.. no power cut outs EVER from the VEGA series card with the HIGHEST TPD rating of any Vega GPU ever released (they relally let the Liquid Cooled VEGA64 model "fly free" in terms of power draw limitations (it's as close to none as any card released).

CAVEAT.... My new [tested and verified working] belief has existed for a week BUT I was on the same side as the consensus for more than a year. Proceed accordingly.

Also noteworthy... 'power balancing' may be the secret ingredient. The fact that I couldn't blow up a Mac Pro with a PSU known to be compromised (highly sensitive at least) using a GPU with a record breaking TPD rating may be a reason for eveyone to own the EVGA Powerlink.......... I don't know :/ (but at least I've TESTED IT!)

it is SUCH a beautiful looking card!

Don't need cMP PCI-e lanes fan anymore!!

GPU 'fan' (liquid cooling unit) stuffed inside case

better close-up on POWERLINK

the all important 'power draw under load' picture. Liquid Cooled is a miracle - look at the Temperature reading!

 

[Mylo3000]

Thanks for your reply and that's really interesting. It seems there's very much a pixals mod or not question over these cards!
How are you connecting the powerlink to the board, what cables are you using? And with the powerlink it's very much just attached to the card, is that right?

 

[zedex]

Here's some pics of the Powerlink (i didn't know what was really happening with this device prior to purchase)..

(2)

The precise answer to your question is as follows: FROM the mini-6pin connectors inside my Mac Pro, I am running two (fairly common, eBay obtained) mini-6pin (male) to PCI-e 8pin GPU power connectors (male) which are then inserted in to the POWERLINK.... and you are done!

PS.. POWERLINK widens your wiring options and permits you to run mini-6pin (male) to standard PCI-e 6pin GPU power connectors (male) which are then inserted in to the POWERLINK.... for the same result.. unless someone is ready to challenge that assertion and i'll have to test it :/

 

[flyproductions]

View attachment 960467

the all important 'power draw under load' picture. Liquid Cooled is a miracle - look at the Temperature reading!

Sorry, but for a card with a TDP of 295 watts you just can not talk of "load" @ 122! Quite sure running Unigine Valley or Heaven (not to talk of FurrMark) for 36 houres would have gotten you into serious trouble!

I have a powerlink too, feeding a GTX 1080. Therefrom i know that it cannot "balance" more than there is. And sadly the load isn't really balanced between the PCIe and the two connectors. In case of the 1080 i did not see the PCIe offer more than about 30 watts at any time. So even with this card with a demand of only 210 watt i am scratching the limit of the two mini 6-pins with the powerlink not beeing able to prevent this from happening.

So for the Vega 56 you are nearly exact in my situation and the powerlink-solution might work. But for a Vega 64 with thrown real load at, there should be no way around additional power if one wants to prevent their machine from getting dammaged.

 

[MIKX]

Dual SATA to single 6 pin cable can also be added to the PowerLink along with the Dual Mini 6 pin cable.
in this case the PowerLink spare 6 pin socket must be changed into the Powerlink.
More info here :

EVGA PowerLink with AMD GPUs

Just got the EVGA PowerLink working with my Sapphire Dual-X 7970 3gb. IMPORTANT : The power input sockets on the PowerLink are 2 X 8 Pin female and cannot be changed. The EVGA PowerLink ensures that exact power demanded by a GPU is supplied. That said, one must still supply enough power to...

forums.macrumors.com

I have used this setup with both an MSI Armor RX 580 8gc and an EFI flashed Sapphire Dual X 7970 successfully as I use X-plane 10 & 11 at hi res settings

 

[flyproductions]

Is it 2 x mini 6 pin to 2 x 8 pin into the powerlink which is connected to the card, or an alternative like dual mini 6 pin to 1x 8 pin. I'm confused on what leads i need.

How you get the output of te two mainboard connectors into the powerlink doesn't make any difference. If you use 2 x mini-6-pin to 1 x 8-pin or 2 x mini-6-pin to 2 x 8 (6+2)-pin, it all gets on the same rails and is drawn by the card's dual 8-pins at it's demands.

 

[zedex]

Everyone here has valid counterpoints. I should have mentioned earlier - I owned a Vega 56 and I was comfortable powering it without PIXLAS.

The new card (VEGA64 LC) could *EASILY* do some damage because I've already proven (with pictures in another post somewhere) that I can get it to draw 650W+ sustained using some of the methods described by @flyproductions (i.e benchmarks and such). I power it using my CUBIX GPU PCI-e expansion enclosure (separate PSU) and I wasn't using my test unit. My more recent test was only good for proving that in my typical day, when I'm just trying to power a 4K@60Hz display output, that the GPU won't draw excessively if you're just doing normal stuff.

I'll find the link to my other post - it's instructive to say the least.

 

[flyproductions]

My more recent test was only good for proving that in my typical day, when I'm just trying to power a 4K@60Hz display output, that the GPU won't draw excessively if you're just doing normal stuff.

On "my typical day" (stuff like ADOBE CC, browsing the web, some Youtube) even having such thing as the 1080 is pure luxury!

Right at the moment it is drawing less than 12 watts alltogether (5.2 of the socket, around 3.5 from each of the mini-6-pins) driving two 27" LED displays and would easily get along without any additional power, if the dual 8-pins just wouldn't have to be connected. But i know that at least older AMD GPUs ar not that modest. The 7950 used to draw 50 to 60 watts just idling.

 

[Mylo3000]

These are all really interesting points and to be honest still make me wonder if not doing the mod is a good idea but I feel that i should see what happens with the powerlink setup as you guys have all helped me with.
What i didn't say is I use my mac for work, running two monitors, cinema 4d with arnold renderer (CPU based) and farily heavy photoshop work. Is that likely to add problems to the power department or is it irrelevant? oh and how long do the 6pin to 8 pin leads need to be?

 

[flyproductions]

Is that likely to add problems to the power department or is it irrelevant? oh and how long do the 6pin to 8 pin leads need to be?

IMHO you will get along nicely with your workload without the PIXLAS-mod or any other additional power source i.e. SATA.

My card is an evga 1080 ftw which is factory overclocked and therefor, unlike other 1080s, has dual 8-pin-connectors too. And also, according to some sources, a slightly higher TDP than the 180 watts of other 1080s (somewhere >200 watts). So it should be 1:1 comparable to the demands of your Vega 56.

Running benchmarks i have seen (very short!) peeks of around 95 watts for the mainboard power connectors. Most of the time the nominal value of 75 was barely exceeded or not even reached. I have yet to see any three digit value! And this was for benchmarks! So for your usual workload and even occasional gaming, the intended setup with the powerlink should be safe to use.

 

[MIKX]

For what it's worth . .

For a GPU with 2 X 8 pin sockets the EVGa PowerLink can be setup like this.

Cables setup for Dual 8 pin socket GPU
​

1. Dual Mini 6pin to 8 pin THEN FROM the PowerLink to the GPU's 2nd. 8 pin socket = 8 pin female to 8 pin male.

2. Dual SATA to SINGLE male 6 pin cable to THE RIGHT SIDE of the GPU'S 1st. 8 pin socket.
This cable DOES NOT CONNECT TO THE PowerLink !

MOST IMPORTANT : Yes, 6 pin cables CAN be connected to an 8 pin SOCKET . . BUT . . .the 6 pin make MUST be plugged into the RIGHT SIDE of the GPU's 8 pin socket.

NOTE The DUAL SATA to 6 pin cable being connected directly to the right side of the GPU's 2nd. 8 pin socket means that the power from the dual SATA is not balanced with the power from the PowerLink but at least both of the GPU's 8 pin sockets are receiving power.

 

[flyproductions]

For what it's worth . .

For a GPU with 2 X 8 pin sockets the EVGa PowerLink can be setup like this.

Cables setup for Dual 8 pin socket GPU
​

1. Dual Mini 6pin to 8 pin THEN FROM the PowerLink to the GPU's 2nd. 8 pin socket = 8 pin female to 8 pin male.

2. Dual SATA to SINGLE male 6 pin cable to THE RIGHT SIDE of the GPU'S 1st. 8 pin socket.
This cable DOES NOT CONNECT TO THE PowerLink !

View attachment 960722
MOST IMPORTANT : Yes, 6 pin cables CAN be connected to an 8 pin SOCKET . . BUT . . .the 6 pin make MUST be plugged into the RIGHT SIDE of the GPU's 8 pin socket.

NOTE The DUAL SATA to 6 pin cable being connected directly to the right side of the GPU's 2nd. 8 pin socket means that the power from the dual SATA is not balanced with the power from the PowerLink but at least both of the GPU's 8 pin sockets are receiving power.

I just don't get the point of this setup. Why not just plugging the 8-pin-male of the dual mini-6-pin to 8-pin cable to one input of the powerlink and the 6-pin male of the dual SATA to 6-pin to the other? Isn't that just the whole purpose of the powerlink: To balance all the power available to the two 8-pin female sockets of the card to the card's demands?

In your setup described the powerlink is just not needed at all as it only loops the dual mini-6-pin to 8-pin to one of the card's 8-pin inputs without balancing anything. Plugging the end of the cable directly to the card would be just the same.

 

[Mylo3000]

I just don't get the point of this setup. Why not just plugging the 8-pin-male of the dual mini-6-pin to 8-pin cable to one input of the powerlink and the 6-pin male of the dual SATA to 6-pin to the other? Isn't that just the whole purpose of the powerlink: To balance all the power available to the two 8-pin female sockets of the card to the card's demands?

In your setup described the powerlink is just not needed at all as it only loops the dual mini-6-pin to 8-pin to one of the card's 8-pin inputs without balancing anything. Plugging the end of the cable directly to the card would be just the same.

@flyproductions How to do i do this setup? Where does the "6-pin male of the dual SATA to 6-pin to the other" come from? I don't really understand. I understand there's 2 x 6 pin outputs on the board but if i want to add more power support presumably this comes from the sata lead but where does that plug into/from in the mac pro? Sounds like I get two different power sources going into the powerlink which can only be a good thing?

 

[MIKX]

Mylo3000 & Flyproductions

Look at post #12

You can insert the DUAL SATA to ONE 6 pin male to EITHER . .

1. The RIGHT SIDE of the PowerLink input 8 pin socket. ( For GPUs with only ONE 8 pin female socket )

or .. .

2. The RIGHT SIDE of the OTHER GPU 8 PIN SOCKET on a GPU that has TWO x 8 pin female sockets.

CHOICE #1 will balance ALL power inputted to the PowerLink.

NOTE 1 : I use choice 1 for my MSI Armor RX 580 8gb as it only has ONE 8 pin female socket.
( This delivers enough power for X-Plane 11 at Hi-Rez

If I had a GPU with TWO x 8 pin female sockets I would use CHOICE #2.

NOTE 2 : Under no circumstances would I use a DUAL SATA to one 8pin as that cable would draw too much power
through the backplane/motherboard.

 

[flyproductions]

Mylo3000 & Flyproductions

Look at post #12

You can insert the DUAL SATA to ONE 6 pin male to EITHER . .

1. The RIGHT SIDE of the PowerLink input 8 pin socket. ( For GPUs with only ONE 8 pin female socket )

or .. .

2. The RIGHT SIDE of the OTHER GPU 8 PIN SOCKET on a GPU that has TWO x 8 pin female sockets.

CHOICE #1 will balance ALL power inputted to the PowerLink.

I still don't get the point!

In particular for cards with two 8-pin-power inputs it makes sense to connect all the available power sources to the powerlink's inputs and then the powerlink to the card's sockets. General purpose of the powerlink is to let the card decide how much power is needed at each input and not to let this decision be made by the power available on a particular source.

 

[flyproductions]

@flyproductions How to do i do this setup? Where does the "6-pin male of the dual SATA to 6-pin to the other" come from? I don't really understand. I understand there's 2 x 6 pin outputs on the board but if i want to add more power support presumably this comes from the sata lead but where does that plug into/from in the mac pro? Sounds like I get two different power sources going into the powerlink which can only be a good thing?

You can use the SATA-connectors at the Mac Pro's hard drive bays to provide additional power if you don't need them for harddrives. For this purpose cables like this one are available. I would prefer those with a 8-pin (6+2-pin) male connector over those with just a 6-pin at the end anyway, as the powerlink only has 8-pin inputs.

As the SATA-connectors power is limited, if you use two of them or only one, depends on how much additional power is needed. The only thing which should be avoided is to connect a single SATA directly to one of the inputs of a card with two 8-pin inputs.

 

[Mylo3000]

Ok makes sense thanks for the info. Now, what if I've got all the bays full with harddrives? Is there anywhere else I can connect a sata lead to?
And just so I've got this right, @flyproductions we're saying connect dual mini 6 min to 8 pin from the board to one of the powerlink 8 pin inputs. Then we connect the (as yet unknown source as I've got 4 drives in) sata source with a sata lead to an 8 pin lead to the other 8 pin input on the powerlink? Oh and in that link why are there two sata connectors?

 

[krakman]

I dont wish to sound rude but this topic has been discussed thouroughly, there is a long thread about it in this forum. Just use the search function at the top of the page. there is a lot of information on that thread which will help you.

The simple solution is this: RX VEGA 56 switch the bios to economy setting - its the little switch on the side of the card. its like low power mode but only about 7% slower in benchmarks then use two mini 6pin to 6pin cables with a Powerlink.

Make sure you are running mojave 10.14.6 or catalina as these had imporvements in the driver and power handling through PCIe.

I have been running a Vega56 with two 6core Intel 3.46 processors running FCPX, Photoshop and Lightroom no problem for the last year or two. FCPX will benefit from the GPU - Photoshop and lightroom still heavily dependant on the CPU

 

[riggieri]

I am running a Vega 56 in performance mode with the DIP switch without power mod.
All you need is a dual mini 6 pin to 8 pin cable and then 8 pin to dual 6 pin or dual 8 pin.

this balances the power draw over both connectors. Been running it like this for a year or so.
Heavy draw from Reaolve, multiple hour long renders maxed out.
Never a problem.

 

[Mylo3000]

thanks @riggieri pardon my ignorance but could you explain that more (sorry) so dual 6 pin from the board? into the 8 pin of the powerlink? then where's the other leads go.

 

[riggieri]

I’m not using the power link.doesn’t fit all cards

using this

COMeap Dual Mini 6 Pin to 8 Pin PCI Express Video Card Power Adapter Cable for Mac Pro Tower/Power Mac G5 15-inch(38cm)

COMeap Dual Mini 6 Pin to 8 Pin PCI Express Video Card Power Adapter Cable for Mac Pro Tower/Power Mac G5 15-inch(38cm)

www.amazon.com

 

[flyproductions]

Ok makes sense thanks for the info. Now, what if I've got all the bays full with harddrives? Is there anywhere else I can connect a sata lead to?

Yes! You can use the SATA power of the spare optical drive bay or, if you do not have any optical drive installed, of both too.

And just so I've got this right, @flyproductions we're saying connect dual mini 6 min to 8 pin from the board to one of the powerlink 8 pin inputs. Then we connect the (as yet unknown source as I've got 4 drives in) sata source with a sata lead to an 8 pin lead to the other 8 pin input on the powerlink?

You can connect any powersource the Mac Pro offers to the powerlink’s inputs. It should sum up and been made available to the gpu connected. That's basically what this part is made for.

 

[flyproductions]

I am running a Vega 56 in performance mode with the DIP switch without power mod.
All you need is a dual mini 6 pin to 8 pin cable and then 8 pin to dual 6 pin or dual 8 pin.

Yes, may not look as nice and clean. But should do the exact same job.

 

[MIKX]

You can use the SATA-connectors at the Mac Pro's hard drive bays to provide additional power if you don't need them for harddrives. For this purpose cables like this one are available. I would prefer those with a 8-pin (6+2-pin) male connector over those with just a 6-pin at the end anyway, as the powerlink only has 8-pin inputs.

As the SATA-connectors power is limited, if you use two of them or only one, depends on how much additional power is needed. The only thing which should be avoided is to connect a single SATA directly to one of the inputs of a card with two 8-pin inputs.

Using Dual SATA to one 8 pin risks drawing too much power through a Mac Pro's backplane.

That is why in post #15 . . . . I expressly warned about that.

Dual SATA to ONE 6 pin is safe.

6 pin and 8 pin cables sockets draw a different amount of power with the 8 pin being the potential offender in regard to 4,1 & 5,1 cMPs power handling abilities. Not worth a failed backplane IMHO.

============================

Having said that, for a DUAL 8 pin GPU. theoretically this would work and balance ALL power to a 2x 8pin socket GPU IF the PowerLink CAN BE FITTED to the GPU.

POWER from the cMP backplane TO the PowerLink's power input sockets​

1. To the PowerLink 8pin input socket.
One Dual Mini 6pin to PowerLink 8 pin input socket
2. Dual SATA to 6 pin OR 8pin to the Powerlink's other 8 pin input socket ( or replace the PowerLink's 2nd. 8 pin
INPUT socket with the included spare 6 pin INPUT socket.

POWER from the PowerLink to the 2 x 8pin GPUs power input sockets​

3. Female 8 pin to Male 8pin cable from the PowerLink's OUT put 8 pin socket . .TO the GPU's Female socket
4. Female 8 pin to 6 pin cable from the PowerLink's other 8 pin output socket TO the RIGHT SIDE of the GPU's OTHER
8 pin female socket.

All power inputted to the PowerLink is now balanced and not overloading the cMP's backplane.

Whilst not supplying as much as the the Pixlas mod the above at least supplies safe SATA power to the total, available balanced power pool.