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220W Dell DA-2 AC adapter discussion

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I would strongly advise you to get the 2nd splitter!

could it be the reason i'm getting black screen when booting with akitio connected?

no monitor is connected to gpu itself, i'm running 2015 rmpb osx 10.10.4

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It depends on the GPU, some can draw a big amount of power through the PCIe slot. Without any load it shouldn't be a big problem.

I don't really understand your problem, could you please explain in detail your setup and your problem?!

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It depends on the GPU, some can draw a big amount of power through the PCIe slot. Without any load it shouldn't be a big problem.

I don't really understand your problem, could you please explain in detail your setup and your problem?!

standard stuff: akitio, dell da-2, kfa2 gtx970. i powered akitio using it's stock psu and gpu with da-2 through 6pin splitter. i've ran the script from goalque with relative success (first couple runs failed because i had osx incompatible sed in my PATH, last one succeeded, i have nvidia web driver installed).

now the problem is if i boot up my macbook normally - everything is fine, nvidia has the checkbox next to it's web driver in system panel.

if i boot up with thunderbolt connected and akitio powered - i get black screen.

P.S. system report shows additional gpu so it's a win, making it primary is apparently not possible at the moment so i'll just get external monitor somewhere.

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P.S. system report shows additional gpu so it's a win, making it primary is apparently not possible at the moment so i'll just get external monitor somewhere.

eGPU with primary display is only possible with an external display connected to the eGPU in OSX.

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@keymone you should not mix psu as this can bring ground loops and potentially damage your equipment.

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@keymone you should not mix psu as this can bring ground loops and potentially damage your equipment.

ugh.. wow. thanks for letting me know. what is ground loops? are there any noob-friendly resources that explain that sort of stuff?

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Paste from google:

In an electrical system, a ground loop is an unwanted current in a conductor connecting two points that are supposed to be at the same potential, often ground, but are actually at different potentials. Ground loops are a major cause of noise, hum, and interference in audio, video, and computer systems.

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I want to use DA-2 with Akitio Enclosure and a 175W GPU with 8pin connector.

According to the very nice introduction by jacobsson, the DA2 has three 12V wires. Trying to minimize soldering efforts, I came up with a wiring diagram, where

  • all three 12V wires are connected with an 8pin GPU power connector
  • only two wires are also connected with Akitio Barrel plug

Assuming that the GPU will consume 75W from PCIe lane and 100W from an 8pin connector, it seems like

  • the total current in one wire will be 100W/3 = 2.8 A
  • the total current in two other wires will be 100W/3 + (10W+75W)/2 = 6.3 A

Do I need to worry about more than 6 amps in those two wires? Are there any specs or information about the DA2 power cord? AWG? Length? Resistance?

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You can simply combine all 12V and ground rails and just use as much wires as you want to power the 8-Pin and the barrel plug (AKiTiO).

Seems like you want to make the Fury Nano work, right? I would wait for reviews to see how much power the card really uses and how much load the card will put on the PCIe slot.

Good cards get the major part on the 6/8-Pin power conenctors and only a fraction of the possible 75W on the slot! So lets hope AMD did a good good and set a small load on the slot!

Edit: The Fury-X is already using almost all it's power from the PCIe plugs and only 10W on the slot:

15-Gaming-PEG-Total_w_600.png

source: https://translate.google.de/translate?sl=de&tl=en&js=y&prev=_t&hl=de&ie=UTF-8&u=http%3A%2F%2Fwww.tomshardware.de%2Fradeon-r9-fury-x-grafikkarte-fiji-gpu%2Ctestberichte-241846-7.html&edit-text=

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You can simply combine all 12V and ground rails and just use as much wires as you want to power the 8-Pin and the barrel plug (AKiTiO).

Seems like you want to make the Fury Nano work, right? I would wait for reviews to see how much power the card really uses and how much load the card will put on the PCIe slot.

It's like you are reading my mind ) I am very interested in the new Fury Nano indeed. Low power consumption at the PCIe slot comparable to Fury-X would be perfect. But coming back to the worst case, it would be still interesting to know the limits of DA2 power cord. Some people say it has 3x 14 AWG - IMHO, more than enough to carry 3x 6 amps and more.

If someone would confirm that, then I would safely apply my simplistic "zero-soldering" wiring.

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Well the DA-2 is rated to output 220W… ;)
Well the DA-2 is rated to output 220W… ;)

Though can deliver up to 12V/20A (240W) according to a couple of taobao vendors:

taobao vendor1

taobao vendor2

<A HREF=http://gd1.alicdn.com/bao/uploaded/i1/TB1RDb8HpXXXXXgaXXXXXXXXXXX_!!0-item_pic.jpg_600x600.jpg><img src=http://gd1.alicdn.com/bao/uploaded/i1/TB1RDb8HpXXXXXgaXXXXXXXXXXX_!!0-item_pic.jpg_600x600.jpg></A>

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@dax: Since the Nano is now reviews it seems like that cards power consumption can peak up to 300W. Might be unstable with the DA-2.

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Hi, I tried to buy one of these and here's the reply

[ATTACH]15903[/ATTACH]

The adapter cable? Guess too many bought it without knowing what it is for.

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@dax: Since the Nano is now reviews it seems like that cards power consumption can peak up to 300W. Might be unstable with the DA-2.

300W is definitely too much for DA-2. But I would call into question such statements. Both PCIe lane (max 75W) and 8pol plug (max 150W) allow max power consumption of 225 Watt, not 300 Watt.

Would you please point me to one of the related reviews?

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That is no problem! Just make sure to use propper and thick wires for the peak loads!

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What does the DA-2 put out when not underload? I've made a cable to power the AKiTio and whilst confirming it was correctly wired I saw the voltage at around 19v. The stated output is 12v. Can someone else please check what their DA-2 does when not loaded?

edit: My multimeter was faulty, after checking with another meter it was showing 12.32v under no load.

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Yes, but some switch-mode PSUs require a minimum amount of load before they'll output the correct voltage. I want to check what others with no load on them.

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