Jump to content

2014 15" MBP GT750M + GTX1070@16Gbps-TB2 (AKiTiO Thunder2) + Win10 (BIOS) [jddh]


jddh

Recommended Posts

I’m pleased as punch to have my first eGPU rig going, and grateful for the generous veterans on this forum that helped me get sorted.

 

Hardware

  • Macbook Pro Mid-2014 2.8Ghz i7-4980HQ 16GB 1TB SSD GT 750M
  • Akitio Thunder2
  • EVGA GTX 1070 SC
  • Dell DA-2 

 

Hardware setup
Scored and bent off the aft part of the inner Akitio to accommodate this boat of a card. 

 

Cabled out from the DA-2 using the 2x6 pin PCIe splitter + paperclip method. Standard screw-terminal barrel adaptor with a little solder and heat shrink. At some point I’ll put a switch on the remote terminal of the DA-2 to power up & down a little more elegantly.

 

On a side note…the 2x6 pin to 8 pin power adaptor that came with the GPU is useless. The female socket pins must be widened or the cable is useless.

 

Software
I uninstalled the NVIDIA drivers on my BC partition and eventually managed to boot with the card while installing. (Eventual) success!

Like everyone, my boot process is often flaky. The card will boot and rev in macOS, of course to no avail at this time, because the drivers aren’t out. However if I boot with the Akitio plugged in, most of the time I won’t even get a boot chime—the card revs up, but the screen stays black, while the CPU fans spin up. As for Windows, I cannot plug in after Win boots—it keeps trying & jiggling its fans, but to no avail. If I boot to the OS chooser and then plug in, 45% of the time, the system will freeze & spin CPU fans as above, never getting past the disk icons. The other 45% of the time, Win 10 will boot, but BSOD with an IRQL_NOT_LESS error and restart. 10% of the time, it works ;)

 

That said, the following process works more than 50% of the time:

  1.  Boot to macOS
  2. Plug in eGPU
  3. Choose my BC partition in Startup Disk
  4. Restart

 

If I get caught in the above freezes, booting through to Windows on my dGPU with the eGPU unplugged, restarting to macOS using the Bootcamp utility, and starting over seems to do the trick the majority of the time. The alt-key OS chooser fails most of the time. I am amazed at how random the process is.

 

Benchmarks
3DMARK 11 18699 (graphics) 14930 (overall)

 

IMG_4251.jpg

IMG_4249.jpg

IMG_4250.jpg

The only thing I don't like is that the backplate of the 1070 is right up against the internal power cable of the Thunder2.

 

Edited by jddh
Link to comment
Share on other sites

  • 2 weeks later...

Having some confusing power supply issues.

 

Occasionally the card and enclosure power down on a GPU intensive app launch, and if not then, often after 30 minutes of driving the card. When/if this happens, the DA-2 light stays on, but I note the Akitio power light goes off too. If I rotate the barrel adaptor a little, the enclosure and card power back on, but of course at this point the computer needs to be rebooted.

 

If I have just the enclosure powered (Thunderbolt not plugged), there are certain orientations of the barrel plug/orientation of the wires to the barrel plug that cause the Akitio to lose its power. Oddly, if the Thunderbolt is plugged in, and so the GTX is powered on, moving the barrel plug does NOT power down the Akitio, though the leds on the card flicker ever so slightly. 

 

So I figure either:

  1. My soldering to fit the wires from all three leads from one side of a 6-pin split into the barrel adaptor was sub-optimal; certain orientations of the wire don't make a great connection and do not supply sufficient power to the system. If the card is plugged in and powered, the substantial power going to the card PCIe plug keeps the system running, but under load, the Akitio/PCI slot is under-powered and the system shuts down.
  2. The system is generally under-powered under load from the DA-2

I suppose both of these problems may apply. I pulled some logs from GPU-Z—last time the card shut off, the card was running fairly consistently at 80% TDP, whereas leading up to that, it was about 10% less. Also, GPU-Z seems to report that most of the time, perfcap is because of "reliability voltage", though as I understand it, NVIDIA percap will always read something, and this may or may not be an actual issue.

 

I took a bit of a chance with a DA-2 on the 1070 SC—it's TDP is 170W. Most others with this card seem to be using ATX PSUs. According to the math on this forum, I believe I ought to have enough theoretical power for everything, though in the real world with soldered wires and a used DA-2, perhaps I'm not quite making the grade.

 

When I have a little time, I'll try a second adaptation to a barrel plug; perhaps a wire-to-wire solder rather than screw terminals. Perhaps will also buy a good PSU with a receipt and see if more power helps stability or performance.

Edited by jddh
Link to comment
Share on other sites

  • 3 weeks later...

I bought an EVGA 550 G2 gold-rated PSU and soldered up a new barrel adaptor. Now running 8-pin PCIe power straight from the PSU to my card, and another 8-pin soldered down to 2x 18 AWG wires to a standard barrel adaptor. I'm not 100% sure the PSU upgrade was necessary, but the soldered power connector to the Akitio is clearly more stable, and I'm more comfortable driving the rig for hours knowing that there's no way I'm shorting power.

 

 

IMG_4286.jpg

Link to comment
Share on other sites

  • Tech Inferno Fan changed the title to 2014 15" MBP GT750M + GTX1070@16Gbps-TB2 (AKiTiO Thunder2) + Win10 (BIOS) [jddh]

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

×
×
  • Create New...

Important Information

By using this site, you agree to our Terms of Use. We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.