Pixlas 4.1 Mac Pro mod

[mani girafe]

what is the correct AWG size for posi tap use ?
because you have 3 versions :

10,12, GA, AWG
14,16, GA, AWG,
20-22, GA, AWG

 

[Executor]

what is the correct AWG size for posi tap use ?
because you have 3 versions :

10,12, GA, AWG
14,16, GA, AWG,
20-22, GA, AWG

10,12 GA is the one I used. See my earlier post for the amazon link.

 

[AndreeOnline]

Thank you to all the people that contributed to the thread. I took the plunge and modified my Mac Pro 5,1.

Looks very nice and clean.

 

[Executor]

Looks very nice and clean.

Thank you so much. I wouldn't have done if it wasn't for you starting the thread. 🙂

 

[Harry322]

I'm finally attempting this mod - but was hoping to get all of my parts quickly via Amazon. Instead of waiting for the custom MOD DIY Open-End to Dual 8 Pin (6+2) PCI-E Sleeved Cable, could I order something like this:

https://www.amazon.com/dp/B07MV4CYMV/ref=cm_sw_em_r_mt_dp_U_6Q1TDbDDEQPG5

and then just snip the ends off myself? Is there a better option on Amazon Prime that anyone can recommend?

Thanks in advance!

 

[wangchungyoon]

I'm finally attempting this mod - but was hoping to get all of my parts quickly via Amazon. Instead of waiting for the custom MOD DIY Open-End to Dual 8 Pin (6+2) PCI-E Sleeved Cable, could I order something like this:

https://www.amazon.com/dp/B07MV4CYMV/ref=cm_sw_em_r_mt_dp_U_6Q1TDbDDEQPG5

and then just snip the ends off myself? Is there a better option on Amazon Prime that anyone can recommend?

Thanks in advance!

I'm doing this right now, as well. I ordered the moddiy cable, but it will take forever to get here. I have an 8-pin to dual 8 pin (6 + 2) cable that came with my corsair powersupply that's in another machine. I want to just cut the end off of this thing and use it. Has anybody used a different cable?

EDIT: I used the regular cable and cut the end off of it. It was just a little more challenging to keep track of the 3 12v wires. I put a little piece of electrical tape around those 3 to not lose track of them. If you do the same thing, make sure your cable is long enough. Mine was almost a little short.

 

[wash34]

Hello,


I made this change but I try to be closer to the origin. So I changed the power to connect directly to it. Here are some pictures ...

Remove all parts

Create a new cables and fix it to the original power cable. I use 8 pins connector from old motherboard.
3 cables have yellow markup for 12v. 5 for ground.

It's look like original 😉

Open the power supply. Becarefull about capacitor !!!

Make solder on the right place ...

After connect an after market 2x 8pins cable behind the dvd rom.

And now it's finish ready for RX VEGA (RX 580 on the picture)

After some test it's working with a RX 56 VEGA from MSI.

 

[zemaker]

Anyone know if I can get all the parts need off of Amazon?

 

[Snow Tiger]

I built an internally powered and installed Dual Vega F.E. cMP System last April by modding the PSU cabling with the necessary taps ( for 4 x 8 pin PCIe booster ) . I was inspired by the Pixlas method and I'm certain I beat Apple to it . You don't need to do any rework on the inside of the PSU . You'd be amazed at how much juice one of these power supplies are capable of actually providing . Got bored with it and it's now sitting in a corner of my shop . I'm spending all my time working with PC and Mac Cascade Lake / Skylake Xeon Systems lately .

Here's a look if you like eye candy :

 

[h9826790]

I built an internally powered and installed Dual Vega F.E. cMP System last April by modding the PSU cabling with the necessary taps ( for 4 x 8 pin PCIe booster ) . I was inspired by the Pixlas method and I'm certain I beat Apple to it . You don't need to do any rework on the inside of the PSU . You'd be amazed at how much juice one of these power supplies are capable of actually providing . Got bored with it and it's now sitting in a corner of my shop . I'm spending all my time working with PC and Mac Cascade Lake / Skylake Xeon Systems lately .

Here's a look if you like eye candy :


View attachment 884745
View attachment 884748

It's interesting to see that my single Radeon VII can beat 2x Vega FE 😁

 

[Snow Tiger]

It's interesting to see that my single Radeon VII can beat 2x Vega FE 😁
View attachment 884760

Nice job ! But my Build was made for production use and was able to stay cool at load for over 48 hours straight , thanks to the blower type coolers of the Vega F.E. that exhaust the hot air outside the Mac . Your Radeon VII has open air type coolers , so all that hot air the GPU generates gets blown right back inside the Mac . Something to consider when you build rendering workstations .

You know what's so interesting ? With the internal wiring provided ( 4 x 8 pin PCIe booster ) , we could actually install two of your Radeon VIIs into my cMP Mac . Maybe getting a Luxball score of over 100,000 ?

However , don't get too excited as these cards installed in Rev 3 PCIe Cascade Lake PCs running Windows improve real world rendering performance by a factor of three or four . One of these days I'll install some Vega F.E.s in my MP 7,1 and see how well they perform . Probably as good as in my C.L. Xeon Windows PC .

 

[tommy chen]

Anyone know if I can get all the parts need off of Amazon?

Mac Pro Pixlas Mod - The House of Moth

Modify your Mac Pro power supply to relieve the board and feed powerhungry GPU's

thehouseofmoth.com

 

[Mihatsu]

I built an internally powered and installed Dual Vega F.E. cMP System last April by modding the PSU cabling with the necessary taps ( for 4 x 8 pin PCIe booster ) . I was inspired by the Pixlas method and I'm certain I beat Apple to it . You don't need to do any rework on the inside of the PSU . You'd be amazed at how much juice one of these power supplies are capable of actually providing . Got bored with it and it's now sitting in a corner of my shop . I'm spending all my time working with PC and Mac Cascade Lake / Skylake Xeon Systems lately .

Here's a look if you like eye candy :

Hi,

I need 4 x 8 pin as well, may I ask how did you split your power cables? 4x8 has 12x12v cables and PSU output has 4x12v cables so did you split the each output to 3x12v or how did you do it?

Thx!

 

[kmgolden]

@Mihatsu It looks like @Snow Tiger used four of these: https://www.moddiy.com/products/Bit...8-Pin-PCIE-to-Open-End-Split-Power-Cable.html, and cut off the additional 8 pin from each.

I'm not sure why that would be necessary/why they didn't just use two normal pcie 8 pin -> 2x 8pin for this application, or just two of the mining cables. Any insight, Snow Tiger?

Based on what I know this would lead to the same outcome, and would use fewer taps; or it could be something about the way these cables are pinned that chose this path for them.

Currently researching this for myself as well. I'm at the point where I'm deciding between buying cables or making my own.

 

[Mihatsu]

@Mihatsu It looks like @Snow Tiger used four of these: https://www.moddiy.com/products/Bit...8-Pin-PCIE-to-Open-End-Split-Power-Cable.html, and cut off the additional 8 pin from each.

I'm not sure why that would be necessary/why they didn't just use two normal pcie 8 pin -> 2x 8pin for this application, or just two of the mining cables. Any insight, Snow Tiger?

Based on what I know this would lead to the same outcome, and would use fewer taps; or it could be something about the way these cables are pinned that chose this path for them.

Currently researching this for myself as well. I'm at the point where I'm deciding between buying cables or making my own.

I actually ordered two of these and installed them yesterday https://www.amazon.com/Express-Adap...NMP29SSTCH8&psc=1&refRID=CFH33JE6YNMP29SSTCH8

flat cable not bend every direction so well but seems to work ok. I'm running two of EVGA GTX 1080ti FTW3 Hybrids without problems.

 

[kmgolden]

That's great! How did you go about splitting the connections from the PSU cable?

 

[Mihatsu]

PSU has 4x pairs of 12v and ground so I used 1x12v and 1xground per 8pin cable. So one 12v PSU cable drives 3x12v pins and 5xground pins.

 

[kmgolden]

Gotcha, makes sense. Nice work, glad you have that up and running.

 

[Snow Tiger]

@Mihatsu It looks like @Snow Tiger used four of these: https://www.moddiy.com/products/Bit...8-Pin-PCIE-to-Open-End-Split-Power-Cable.html, and cut off the additional 8 pin from each.

I'm not sure why that would be necessary/why they didn't just use two normal pcie 8 pin -> 2x 8pin for this application, or just two of the mining cables. Any insight, Snow Tiger?

Based on what I know this would lead to the same outcome, and would use fewer taps; or it could be something about the way these cables are pinned that chose this path for them.

Currently researching this for myself as well. I'm at the point where I'm deciding between buying cables or making my own.

I used PCIe power cables ( modDIY SKU: CO1011 ) that had sufficient gauge to handle the anticipated load ( 150 W ) for each 8 pin connector . Gauge depends very much on the length of the cable .

Dual 8 Pin PCIE to Open End Split Power Cable

Buy Dual 8 Pin PCIE to Open End Split Power Cable for $9.99 with Free Shipping Worldwide (In Stock)

www.moddiy.com

Use only one of the two 8 pin PCIe connectors on each of these cables . Cut off the other 8 pin connector and use several liberal coats of liquid electrical tape to insulate the unused wire(s) , to avoid potential shorts . Never use both 8 pin connectors on the same cable .

Use one of these cables for each of the four factory PSU 12 V rail wires and four ground wires . Do not share factory wires between the four 8 pin PCIe cables . You want to evenly distribute the load , so each 8 pin PCIe cable has an unique factory PSU 12 V rail and ground wire .

This will give you a stable System under load . I ran two Vega F.E.s with a cMP at continuous load for 12 - 24 hours without issue . Both those cards consumed a total of around 660 W from the factory PSU in a single processor cMP . You should be able to run a Dual Radeon VII with this configuration , too .

Here are the taps I used - you will need a total of eight taps for four 8 pin PCIe connectors . One tap for each of the four 12 V and four ground wires .

3M GENUINE SCOTCHLOK 562 YELLOW QUICK SPLICE WIRE CONNECTORS 12-10 AWG 25 PCS

3M GENUINE SCOTCHLOK 562 YELLOW QUICK SPLICE WIRE CONNECTORS 12-10 AWG 25 PCS | eBay

Find many great new & used options and get the best deals for 3M GENUINE SCOTCHLOK 562 YELLOW QUICK SPLICE WIRE CONNECTORS 12-10 AWG 25 PCS at the best online prices at eBay! Free shipping for many products!

www.ebay.com

 

[kmgolden]

@Snow Tiger awesome! Thank you so much for the detailed reply. It's very helpful to me, and I think that'll be helpful to other dual-gpu folks on this thread. Makes sense re load distribution. I'll likely do the same and report back with pics when complete.

Thanks again!

 

[Joka80]

Hello all!🙂

Such a great thread and thank you to everyone who has contributed to ideas and ways of doing the mod. Great write up at the beginning Andree too.

I have a question, I have ordered the same brown coloured wire splices that you used to create the mod. One side which accepts the thicker 10-12AWG PSU cable and the other side of the connector which accepts the slightly thinner (can’t remember the gauge) wire width from the moddiy.com cable.

Am I correct in thinking that these splices just go onto the PSU cable and they’ll cut through the insulation on there own or did you make an incision with a blade on the insulation first? Parts of me thinks that it’s only necessary to put the connectors straight on as if I made an incision there is a risk of actually cutting into the wire as the splice goes on...?

If someone can confirm that would be awesome and everyone’s Mac’s look awesome with the mod. Great work.

 

[Snow Tiger]

Am I correct in thinking that these splices just go onto the PSU cable and they’ll cut through the insulation on there own or did you make an incision with a blade on the insulation first? Parts of me thinks that it’s only necessary to put the connectors straight on as if I made an incision there is a risk of actually cutting into the wire as the splice goes on...?

With my 3M GENUINE SCOTCHLOK 562 YELLOW taps I had to use a Channellock 348 Linesman Plier to secure them properly . Locking the taps just with hands is not possible . No incision by knife is necessary .

Channellock Pliers 348 HL Combination Plier - High Carbon Steel, Gripping - 8.5 in

Channel lock Inc 8-1/2" Drop Forged Steel Hand-Honed Linesman Pliers are long lasting and are constructed with a heavy duty design. Features laser heat treated cutters and Western electric spec B8 comfort grips providing convenient, hassle-free use.

www.amazon.com

 

[Joka80]

With my 3M GENUINE SCOTCHLOK 562 YELLOW taps I had to use a Channellock 348 Linesman Plier to secure them properly . Locking the taps just with hands is not possible . No incision by knife is necessary .

Channellock Pliers 348 HL Combination Plier - High Carbon Steel, Gripping - 8.5 in

Channel lock Inc 8-1/2" Drop Forged Steel Hand-Honed Linesman Pliers are long lasting and are constructed with a heavy duty design. Features laser heat treated cutters and Western electric spec B8 comfort grips providing convenient, hassle-free use.

www.amazon.com

Thank you for your reply.
Yes, sorry I have a pair of Mole Grips Pliers which I have adjusted to the correct tension in order to avoid crushing the splice so it gets a good grip and also able to push down the metal tab in the splice.

I just wasn’t sure whether I had to make an incision in the cable with a knife before putting on the splice.

The splices I used are these:

878211D MULTICOMP PRO, Wire Splice, Crimp, 18 AWG | Farnell® UK

Buy 878211D - MULTICOMP PRO - Wire Splice, Crimp, 18 AWG. Farnell® UK offers fast quotes, same day dispatch, fast delivery, wide inventory, datasheets & technical support.

uk.farnell.com

[automerge]1584205290[/automerge]

They are the same splices that Andree linked to at the beginning of this thread. They are 10-12AWG in one hole and 14-18AWG on the other hole so I guess they can do both jobs at once. I was just querying the fact that Jay at House Of Moth used slightly different splices but made a cut first.

Even with mole grips, it was hard to push the cable down initially, presumably due to the thickness of the PSU wire insulation, but once the ‘cut’ got started it just went down without any issue but yes it needed some force to go on. The splice actually cuts through the wire in two separate places about 5mm apart presumably for a more solid connection.

 

[Snow Tiger]

Thank you for your reply.
Yes, sorry I have a pair of Mole Grips Pliers which I have adjusted to the correct tension in order to avoid crushing the splice so it gets a good grip and also able to push down the metal tab in the splice.

I just wasn’t sure whether I had to make an incision in the cable with a knife before putting on the splice.

The splices I used are these:

878211D MULTICOMP PRO, Wire Splice, Crimp, 18 AWG | Farnell® UK

Buy 878211D - MULTICOMP PRO - Wire Splice, Crimp, 18 AWG. Farnell® UK offers fast quotes, same day dispatch, fast delivery, wide inventory, datasheets & technical support.

uk.farnell.com

[automerge]1584205290[/automerge]

They are the same splices that Andree linked to at the beginning of this thread. They are 10-12AWG in one hole and 14-18AWG on the other hole so I guess they can do both jobs at once. I was just querying the fact that Jay at House Of Moth used slightly different splices but made a cut first.

Even with mole grips, it was hard to push the cable down initially, presumably due to the thickness of the PSU wire insulation, but once the ‘cut’ got started it just went down without any issue but yes it needed some force to go on. The splice actually cuts through the wire in two separate places about 5mm apart presumably for a more solid connection.

I had to scrap one uninstalled PSU in order to learn how to attach the taps properly to the cable lines . After installing around three or four "test" taps I was ready to work on the real PSU that was eventually installed in the Mac . It was easy after the test taps . Yes , you have to be careful not to apply too much torque or you'll crush the connection . I installed the taps on the PSU cable while it was uninstalled and snaked the modded cable into the ODD bay from the PSU Bay . Once the PSU was properly fastened , I snaked the four 8 Pin booster cables from the PCIe Air Channel into the ODD bay and secured the ends to the taps to complete the connections . There are holes in the Media Bar large enough to do this .

 

[tommy chen]

i have now completed about 20 pixas mod and the biggest challenge is the stripping and finding the right distance.
checking that all connections are perfect is a matter of course!

but if you follow the instructions not much can go wrong:

Mac Pro Pixlas Mod - The House of Moth

Modify your Mac Pro power supply to relieve the board and feed powerhungry GPU's

thehouseofmoth.com

even if you take the greatest care, this is done for everyone max in 90 minutes

.