Boot Camp Assistant horribly slow at creating Windows 7 USB

[area5x1]

I'm creating a Windows 7 install USB device through the Boot Camp Assistant and the process is painfully slow. At first I thought it was my flash drive so for an experiment I tried just copying the ISO over to the flash drive. That seemed to go fine at a decent speed. However when it's actually creating the USB install drive it would seem to go at about 100 kB / second. I would stay in the folder and watch the size of the "install.wim" file go up very slowly, probably at a rate of less than 500 kB / second.

I looked at Activity Monitor and it seems that my Data Read rate is hard-capped at 1 mB / sec, while my Data Write speed is capped around 200 kB / second. Could this be why? What would be the cause for those limits?

I am using a base Retina MBP.

 

[dbyway]

Does it get stuck at what looks like 40%?

 

[area5x1]

Does it get stuck at what looks like 40%?

If I select "Download supporting software" along with "Create a USB Install Drive", yes.

Otherwise, if I select "Create a USB Install Drive" alone, it gets stuck at what looks like 80%

 

[lannisters4life]

Just try another USB if you've got it on hand. I had a Sandisk branded one which got stuck in Boot Camp Assistant, and then I went and bought a new Lexar one, which worked fine (on 2012 MBA).

 

[rmatosinhos]

Here's a little trick. While you are creating the boot disk, send that file over airdrop to a computer at the same time
If you check in the activity monitor /disks the speed will increase