Win7 Guest on Mac OS & Win7 hosts from external drive

[mpack]

this usb flash I think it has same technology as an ssd drive “Mlc” so for this reason I try to run VMs.

I'm afraid not. Yes, the underlying memory is NAND flash in both cases, however the connection technology makes a huge difference. A locally attached SSD can handle thousands of outstanding I/O ops at the same time, allowing it to make full use of the theoretical bandwidth (no seek penalty for jumping between ops). I'm not sure what the IOP limit is on USB3 devices, but I'm pretty sure it was 1 on USB2 devices, and won't be a very big number now.

[socratis]

I haven't done any extensive testing, as I don't normally run things from a USB. Maybe watching a movie or something, but mainly read-only operations, and not tremendous I/O requirements.

However, I had to install a VM/OS on an external USB3 hard drive. The results were really slow, and really puzzling. The bottleneck is most certainly not the speed of the hard drive. See my tests at "OSX, bootcamp on ext. USB3, native boot: USB performance".

It takes about 5-10' for my computer to start a Win10 OS from the USB3 HD and the same to start it as a VM. I need to remeasure the speeds now that everything is pretty much settled...