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

[flyproductions]

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.

Again i do not get the point.

As most of the dual mini-6-pin to 8-pin (or SATA/dual-SATA to 8-pin) cables are not really "to 8-pin" but instead to 6+2-pin (meaning 2 of the 6 pins are just looped to the 2 additional pins!) cables, how could "to one 8-pin" be risky but "to one 6-pin" be "safe"?

As for the dual 8-pin-input GPUs, should work as follows: Usually both inputs have to be connected. Otherwise the card will not even work at all. An then the card will draw the power it needs at each input. No matter if there is a 6- or 8-pin connected. If the power needed is not available it will just not work properly. But if there is a risk of "drawing too much power through a Mac Pro's backplane", this is the case if you connect something directly to one of the card's inputs instead of letting the powerlink balance things out.

or replace the PowerLink's 2nd. 8 pin INPUT socket with the included spare 6 pin INPUT socket.

At least my powerlink did not come with an additional input included. The only thing included, was an additional 6-pin-male-output which can be swapped for one of the 8-pins for cards that have one 8-pin and one 6-pin input instead of dual 8-pins.

 

[MIKX]

How much power does a DUAL SATA to ONE 8 pin cable GPU socket demand from a 4, or 5,1 cMP's backplane for an 8 pin GPU socket = regardless of whether the GPU has one or two 8 pin power input sockets ?

( Assume that additionally the cMP's Dual Mini 6 pins to one 8 pin are already in use in drawing power through the backplane for the 8 pin GPU. ).


To simplify :

How much power does a DUAL SATA to ONE 6 pin cable allow ?

How much does a Dual SATA to ONE 8pin cable allow ?

Count up the total wattage demanded through the cMP's backplane.

 

[flyproductions]

Count up the total wattage demanded through the cMP's backplane.

Yes, this is the exact reason why the PIXLAS-mod ist the better way to go for any card with a TDP of ~ 200 watts and up. But you will not be able to "limit" a card’s power draw by just sticking a 6-pin plug into an 8-pin socket.

 

[Mylo3000]

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.

Thanks for all your feedback @flyproductions so I'm going to use the spare optical drive power. So do i connect both sata bits to this and then the 8 pin to the powerlink?

 

[Mylo3000]

Hi all,
I posted the above a while back now but only now am i getting round to this upgrade.
Im planning on using connection plan in post #25 and I'm wondering where i can connect the dual sata leads to.
Would using one of the opitcal bay connections and one hard drive connection work or is there a better place to connect to?

Thanks!

 

[rx78]

Hi all,
I posted the above a while back now but only now am i getting round to this upgrade.
Im planning on using connection plan in post #25 and I'm wondering where i can connect the dual sata leads to.
Would using one of the opitcal bay connections and one hard drive connection work or is there a better place to connect to?

Thanks!

You'll probably be better off using two of the four hard drive bays for your dual SATA power cable, as you'll struggle to get the cabling up from the PCIE area to the optical bay (unless you're able to remove the SATA head from the cable, push the cabling through the tiny hole up to the optical bay, then reattach?)

 

[Mylo3000]

You'll probably be better off using two of the four hard drive bays for your dual SATA power cable, as you'll struggle to get the cabling up from the PCIE area to the optical bay (unless you're able to remove the SATA head from the cable, push the cabling through the tiny hole up to the optical bay, then reattach?)

Thanks @rx78, I see you have a vega 56. How do you power yours?

 

[mikas]

I've tried both solutions mentioned right there above. I really don't know which one is a better or a safer one to use.
All I can say is that I did use a Vega56 (low bios switch set to "on") 10 months, and ran it with 2x mini 6 pins + 2xSATA power from optical bay. There was no powerlink used in between during that time.

Still, that's not all of it:
Optical bay SATA power comes from through two tiny connectors only, and that power have to passage through motherboard to that connector.
HDD SATA power comes from - who knows, it's all hidden under the motherboard layers, from unknown number of MB leads.

Apple engineers did not know what we are going to use these machines for something like ten years after. Neither is there any means to find out what they thought at that time about power usage in 2020-2021..

I'd like to add, that i have tried a Radeon VII with this exact method too. And it worked ok. Ran LuxMark too.
I just did not want to go any further with my luck. I just did a Pixlas mod lately, and I feel much better now. I could do 2x VIIs doing LuxBall without an interrupt. One though Pixlas mod feed, and one through 2xm6pins+2xsata pwr.

Anyway, not everyone wants to go there and do that power mod. And maybe not everyone is capable of that either.
It's not that hard, but we are different with our skills. Some of us can do some stuff pretty well, and some others do something quite the opposite stuff real good.

Sorry about the long prolog.

I have been wrong and I have been lost too. Now I think I am not so much anymore.

Here you have some clips from my own experiments. You certainly better read all the answers and corrections by MR forum members. There's always a mismatch or some other glitch in the matrix.

The most powerful Graphics Card
GPU Compatibility List for cMP
GPU Compatibility List for cMP
MAC PRO 4,1 and 5,1 PCIe AUX Power
What do I lose if I go High Sierra and 1080 Ti?

To conclude my almost late night post (greenwich time +2):

In your case I would probably read the last link, and go further from there.

"
So if your choice would be a Vega 56, I personally would advice in this order:

1) Pixlas mod (you can use any other card too with this)

If low power bios selected (there is dip switch in most of the cards, but not all)

2) 2x mini 6-pin to 8-pin and 2x sata power to 6-pin
a) with power link in between (lots of cabling needed)
b) without PowerLink (my setup as of today)

3) 2x mini 6-pin
a) power balancing with powerlink
b) power balancing with cable balancing (use forum search for this, there are good advice)

I wouldn't use option 3 myself if I had free sata power connectors, and at least not without some kind of power balance. Without power balancing shutdowns would become inevitable at times. Or worse still, maybe something will actually burn.
"

 

[Mylo3000]

I've tried both solutions mentioned right there above. I really don't know which one is a better or a safer one to use.
All I can say is that I did use a Vega56 (low bios switch set to "on") 10 months, and ran it with 2x mini 6 pins + 2xSATA power from optical bay. There was no powerlink used in between during that time.

Still, that's not all of it:
Optical bay SATA power comes from through two tiny connectors only, and that power have to passage through motherboard to that connector.
HDD SATA power comes from - who knows, it's all hidden under the motherboard layers, from unknown number of MB leads.

Apple engineers did not know what we are going to use these machines for something like ten years after. Neither is there any means to find out what they thought at that time about power usage in 2020-2021..

I'd like to add, that i have tried a Radeon VII with this exact method too. And it worked ok. Ran LuxMark too.
I just did not want to go any further with my luck. I just did a Pixlas mod lately, and I feel much better now. I could do 2x VIIs doing LuxBall without an interrupt. One though Pixlas mod feed, and one through 2xm6pins+2xsata pwr.

Anyway, not everyone wants to go there and do that power mod. And maybe not everyone is capable of that either.
It's not that hard, but we are different with our skills. Some of us can do some stuff pretty well, and some others do something quite the opposite stuff real good.

Sorry about the long prolog.

I have been wrong and I have been lost too. Now I think I am not so much anymore.

Here you have some clips from my own experiments. You certainly better read all the answers and corrections by MR forum members. There's always a mismatch or some other glitch in the matrix.

The most powerful Graphics Card
GPU Compatibility List for cMP
GPU Compatibility List for cMP
MAC PRO 4,1 and 5,1 PCIe AUX Power
What do I lose if I go High Sierra and 1080 Ti?

To conclude my almost late night post (greenwich time +2):

In your case I would probably read the last link, and go further from there.

"
So if your choice would be a Vega 56, I personally would advice in this order:

1) Pixlas mod (you can use any other card too with this)

If low power bios selected (there is dip switch in most of the cards, but not all)

2) 2x mini 6-pin to 8-pin and 2x sata power to 6-pin
a) with power link in between (lots of cabling needed)
b) without PowerLink (my setup as of today)

3) 2x mini 6-pin
a) power balancing with powerlink
b) power balancing with cable balancing (use forum search for this, there are good advice)

I wouldn't use option 3 myself if I had free sata power connectors, and at least not without some kind of power balance. Without power balancing shutdowns would become inevitable at times. Or worse still, maybe something will actually burn.
"

@mikas many thanks for your reply and words. You've some good points here. I'm going to look at the links now and hopefully make a decision.

If I'm honest, I'm thinking about doing the power mod, it doesn't look that hard and i feel like it's a safer bet however if I go for option 2
"2) 2x mini 6-pin to 8-pin and 2x sata power to 6-pin
a) with power link in between (lots of cabling needed)"

How do you connect to the optical bay connections, what is the cable i need?

 

[mikas]

If you manage to pull your existing cable out of the Mac easily enough, you can use the existing ODD cable. Just route it differently after pulling it out.

option 2:
I bought a used one(s) from bookyard, and just unplugged the original optical bay cable, and then attached my second cable, and to that attached a 2xSATA to 6-pin. That way I could close the Mac Pro side cover, and there were no cables in between.

I think there are pictures of this approachment too in those links, if I remember it right.

This is what you want to avoid:

And with this:

You can avoid the above glitch like this:

 

[mikas]

As I have previously said/posted, Personally I have converted my rendermachine to Pixlas mod just recently. It's probably the best option, though not for everyone, I recon.

 

[Mylo3000]

As I have previously said/posted, Personally I have converted my rendermachine to Pixlas mod just recently. It's probably the best option, though not for everyone, I recon.

Ok thanks for the options. Makes sense with the optical cable. Did you reroute it by taking the backplate off?

And can i ask, you say you're using it as a render machine. I use my for work, cinema 4d with arnold (using cpu not gpu currently. Have you had shutdowns before doing the mod using the sata method?

 

[mikas]

I originally did this cable mod for architectural GPU rendering, and I haven't had any shutdowns with twinmotion 'till this day.

I bought an extra ODD cable 2nd hand, routed it to GPU with the adapter cables. You can just leave the existing one hanging in there, it's juast not connected to anything anymore.

Still I do recommend Pixlas. In my opinion it makes sense the most out of all these mods.

 

[mikas]

One more pic to clarify the solution without Pixlas mods (Vega56 + low bios dip switched):
There are two ODD cables in the Mac Pro now. A "New" one (used one), is connected to SATA power MB connector, and the original is not anymore connected or used for anything whatsoever. It just hangs in there. The newly routed cable feeds power to Vega56 6-pin connector. ANd you can close the side cover of the Mac Pro this way. No cables in between anymore.

attch: (power connectors are marked with colours)

 

[Mylo3000]

One more pic to clarify the solution without Pixlas mods (Vega56 + low bios dip switched):
There are two ODD cables in the Mac Pro now. A "New" one (used one), is connected to SATA power MB connector, and the original is not anymore connected or used for anything whatsoever. It just hangs in there. The newly routed cable feeds power to Vega56 6-pin connector. ANd you can close the side cover of the Mac Pro this way. No cables in between anymore.

attch: (power connectors are marked with colours)

I think I understand, so you’ve unplugged the original cable from the board and then used your new cable and plugged it into the same location and then connected this to the dual sata lead? Where about is the prom gal cable plugged in to?

 

[mikas]

I'm not quite sure what you ment with your last question (last sentence), but yes, I think you thought it allright. I just forwarded the ODD power feed like this to the card. And closed the lid.

 

[Mylo3000]

I'm not quite sure what you ment with your last question (last sentence), but yes, I think you thought it allright. I just forwarded the ODD power feed like this to the card.
View attachment 1711592

Ok yes I think understand.
I mean't in my last post that you unplugged the original cable from the board in the main compartment and connected the new cable there and then connected the dual sata cable to the "new"odd cable.
I\m going to buy a new cable now and go down that road before the mod i think
Thanks for your help!

 

[mikas]

You're welcome.
ps. I suggest you use the "power save" dip switch on that Vega56. Just to make sure.

 

[rx78]

Thanks @rx78, I see you have a vega 56. How do you power yours?

A bit late to the party but i did mine differently as i didn't want to do the pixlas mod, and didn't want to use the mini6-PCIE cables, and didn't want to push too much power through the backplane as they're getting old and i want to use this Mac as long as I can.

I power mine with an ATX PSU that i trigger on using add2psu, which piggy backs off a SATA power splitter cable powering my USB 3 card (itself powered from a SATA power cable to the internal HDD bay4). The add2psu board should only draw tiny amounts to trigger the PSU on and off so it should be fine. I use small cable ties to keep the connectors snug.

Then i drilled (!) a big enough hole through a spare (!) Mac Pro side panel to pass through the 2x 8pin GPU power connectors from the PSU to the Vega. I also use the additional SATA power connectors from the PSU to power a small fan to keep the Northbridge cool, and another Noctua fan to keep the HDDs on the PCIE slots cool(er).

An additional note, I found a 1,1 side panel will fit a 4,1 if you take off the big sponges on the panel. I had a spare 1,1 chassis I had planned to take apart for a proper ATX build but never got round to it.

Everything powers on and off with the Mac power button. Vega at default (non power save) BIOS.

Works great. Aesthetics might not be everyone's taste but i can live with it.

 

[rx78]

If you manage to pull your existing cable out of the Mac easily enough, you can use the existing ODD cable. Just route it differently after pulling it out.

option 2:
I bought a used one(s) from bookyard, and just unplugged the original optical bay cable, and then attached my second cable, and to that attached a 2xSATA to 6-pin. That way I could close the Mac Pro side cover, and there were no cables in between.

I think there are pictures of this approachment too in those links, if I remember it right.

This is what you want to avoid:
View attachment 1711546
And with this:
View attachment 1711548
You can avoid the above glitch like this:
View attachment 1711550

Man that looks cool. If i ever decide to go the internal route again i might do this.

 

[mrkapqa]

hello, got the RX vega 56 dragon, unfortunately the PowerLink is of NoUse as it seems for this card.

at the moment i am just testing card, with 1xmini6pin to 6pin and 1xmini6pin to 8 pin cable.
the card functions, but benchmark low (in the range of rx580).

so i guess would need more power,
but is it enough to use instead of 2xsata to 6 pin connected from the SuperdriveBay, only a 1xsata to 6pin (so as to not loose DVD-Drive), and then a 2xmini6pin to 8pin cable instead of the cables in use atm?

 

[h9826790]

hello, got the RX vega 56 dragon, unfortunately the PowerLink is of NoUse as it seems for this card.

at the moment i am just testing card, with 1xmini6pin to 6pin and 1xmini6pin to 8 pin cable.
the card functions, but benchmark low (in the range of rx580).

so i guess would need more power,
but is it enough to use instead of 2xsata to 6 pin connected from the SuperdriveBay, only a 1xsata to 6pin (so as to not loose DVD-Drive), and then a 2xmini6pin to 8pin cable instead of the cables in use atm?

I don't think that's power related. The card don't know how you power it. It just draw whatever it need. If the cMP (e.g. mini 6pin) is overloaded by too much, the shutdown protection will be activated. The card won't lower itself's performance to draw less.

Use Luxmark to measure the performance difference. GB Metal test is extreme VRAM bandwidth limiting. Without RadeonBoost to "unlock" the Apple artificially limited HBM bandwidth, your GB Metal score will be about half of what your card can actually does.

Tired of low Geekbench scores? Use RadeonBoost!

OUTDATED. PLEASE DON'T USE THIS KEXT ON ANYTHING LATER THAN CATALINA. THIS KEXT IS NOT BEING MAINTAINED ANYMORE BECAUSE I SWITCHED TO APPLE SILICON MACS Hello everyone! Together with the help of @DSM2.Hackintosh I built a Kext aiming at removing limitations put in place by Apple for PC...

forums.macrumors.com

 

[krakman]

hello, got the RX vega 56 dragon, unfortunately the PowerLink is of NoUse as it seems for this card.

at the moment i am just testing card, with 1xmini6pin to 6pin and 1xmini6pin to 8 pin cable.
the card functions, but benchmark low (in the range of rx580).

so i guess would need more power,
but is it enough to use instead of 2xsata to 6 pin connected from the SuperdriveBay, only a 1xsata to 6pin (so as to not loose DVD-Drive), and then a 2xmini6pin to 8pin cable instead of the cables in use atm?

where dd you buy the RX vega 56 dragon from?

A lot of second hand cards have firmware flashed for bitcoin mining = low performance

 

[mrkapqa]

yes, ebay, it is said to have been used for gaming only,
the BIOS switch is on the left-side;
tested quick with Geekbench 5 on 10.14.6 (via Opencore M.Lo 0.8) and 12.6.3 (via Opencore, ditto), and results are just for OpenCL for both OS around 50.000 (whereas RX 580 reached around 46.000)

just wondering, probably i can find a better power-delivery-setup. and numbers should improve.

 

[mrkapqa]

what noticed:

RedDragon RX Vega 56

1. this card is quite silent.
2. DP to VGA adapter i have would not function on both DP port (only for bootscreen, but not on desktop) > maybe another Adapter would be needed (active DP to Vga?)
3. Luxmark 3.1 is similar on Windows 11 (nearly 29,000) and MacOS Monterey (plus 27,000) against only 13.000 of RX 580;
however, Geekbench5 OpenCL on Windows 11 around 72,000 versus only 50,000 on MacOS, so i suppose i have a "handbraked" OC setup, which is not optimal, but OK.

the proper cable setup desired or needed leaves me still bit confused,
but should get clarification.