Bean

1. Please read my guide: http://forum.techinferno.com/diy-e-gpu-projects/10061-basic-egpu-hardware-guide-macs.html

2. it is 12V, please don't use 19,5V

3. "use an old PSU…" well, it depends. It should have the required plugs to power the GPU and enough amps on the 12V rail! Don't be "smart" and imagine that a 300W ATX PSU can power a GTX 960, it might not be the case.

A GTX 750 (Ti) can be powered with a 120W 12V PSU (with barrel plug).

A GTX 960 or 970 can be powered by a 220W Dell PSU

Faster cards need desktop PSUs with more than 500W, yes more than 500! Even a GTX 960 should have a desktop PSU with at least 400-450W.

Isn't the 400W for minimal system power-up if you're using a desktop (for GTX 960)? I agree that you may need more power than the TDP of your graphics card but afaik as an eGPU 300W should be plenty for a GTX 960.

Hi all,

After reading many posts about EGPUs and the results with older laptops, I'm finally going to try and build my own EGPU for my Lenovo T420. Apparently there's a ton of topics already regarding this particular laptop, so much that I need to ask questions to straighten things out. So to start I'm going to list the specs of my laptop:

Lenovo T420 w/win7

Processor [email protected]

iGPU Intel HD Graphics 3000 + dGPU NVS 4200 with Optimus

16 GB RAM

What I have in mind is to make a EGPU with GTX 960 (on the way) and connect it to the PE4L-EC060A that I'm getting too. PSU-wise I went safe and got myself a 500W ATX-PSU.

Now for the questions:

1. I've read the 100% CPU thread and apparently Tech Inferno Fan explained that the Optimus-equipped T420 will not have memory issues because the eGPU can hijack the dGPU memory allocation. Does this mean my system should be a plug-and-play or do I still have to manually change settings (DSDT, Setup 1.x, uninstall nvidia drivers etc.)?

2. Will I have compatibility issues regarding my setup with GTX 960 and the PCI-Unit PE4L-EC060A? I was trying to find answers but apparently not a lot of people had problems with this unit so I'm just making sure.

3. For now I'm going to use my internal monitor due to budget constraint. Will I have any issues regarding my settings?

If anyone has experience with this unit and could share some infos about it, I'd be grateful and prepare my settings while waiting for my orders to arrive.

I'll also try and make 3dmark benchmarks if this works for me.