About a year ago I explored the possibility of a DIY external GPU setup. I had an ATI HD 5770, a 1000 watt PSU and a 7 year old Dell laptop all collecting dust and thought it would be a fun little project.
Long story short it was extremely easy to setup and performance was the same as having the card in a desktop. All I needed was a ExpressCard Bus to PCIe-x1 cable (part# PE4L-EC060A), install the GPU drivers (my case the AMD drivers) and had hashcat up and running in no time.
I did have reliability issues where the driver would crash on certain hash types forcing a restart of the laptop. Will have to fire it up again to see if reliability has improved with newer drivers and hashcat but for the most part it worked really good.
Long story short it was extremely easy to setup and performance was the same as having the card in a desktop. All I needed was a ExpressCard Bus to PCIe-x1 cable (part# PE4L-EC060A), install the GPU drivers (my case the AMD drivers) and had hashcat up and running in no time.
I did have reliability issues where the driver would crash on certain hash types forcing a restart of the laptop. Will have to fire it up again to see if reliability has improved with newer drivers and hashcat but for the most part it worked really good.