eGPU Implementation
Lenovo Thinkpad W520
i7-2720QM
16GB RAM (2x8GB)
Quadro 2000M (disabled in bios)
Bios 1.42 without whitelist
Win8.1+Ubuntu 14.04+Linux Mint 17
eGPU:
Asus GTX 670 DirectCUII / Gigabyte GTX 560
EXP GDC 6.0
220W DA-2 PSU from ebay
coolermaster PCIE 6pin to 2x6+2pin
1.2Opt
Updated Benchmarks
all performed under Win 8.1, except where noted
Benchmark External LCD/Internal LCD
3Dmark11 8507 GPU / 7237 GPU
Fire Strike 6597 GPU / 4959 GPU
Sky Diver 20272 GPU / 10327 GPU (50% performance hit!)
Cloud Gate 38794 GPU / 11069 GPU (71% performance hit!)
with a GTX 560:
3DMark11 3827 GPU / fail (would not start on internal screen for reasons unknown, everything else worked fine)
Fire Strike 2577 GPU / 2367 GPU
Sky Diver 8285 GPU / 6257 GPU
Cloud Gate 21451 GPU / 8482 GPU
Desktop (with the 670, win 7) for comparison:
3DMark11 9750 GPU
just dGPU (Quadro 2000M): (you can see I was using 24GB/Win 7 here before this fiasco)
3DMark11: 1838 GPU
while trying to get the eGPU to work I also tested the GTX 560 on my old laptop, a Dell 1520, I think this was using a 1.1 link, no optimus
3DMark11: 2317 GPU
Benchmark notes
The internal display performance hit was more than I was expected. looks like cloud gate is the new 3dmark06? is it possible that optimus compression isn't set up properly on my laptop? I do have the optimus indicator
Experience
I expected it to be plug and play given all the other thinkpad experiences, but I experienced a huge slowdown when I booted up with my eGPU attached. it was the 100% CPU usage issue people with the x230 had when they tried to boot in 16GB. turns out having 24GB of RAM was a problem (2x4GB+2x8GB) and no one had that much RAM in the charts, but16GB works fine with most thinkpads as everyone else reported. I didn't try setup 1.x to fix it, but I tried about everything else, including upgrading from windows 7 to 8, and different versions of linux. it seems to be an OS- independent issue.
as soon as I reverted to 16GB it was plug and play.
it even works in linux as you'd expect, even with the dGPU turned on at the same time, but no optimus compression as far as I can tell. I haven't tried too hard to get that to work with nvidia's PRIME, but it might be possible.
I would have used the PE4C v2, but it wasn't in stock, so I ordered the EXP GDC.
Pics
Current setup:
Internal display works, must be using optimus, no?
old laptop with GTX 560: