When I switched to the Retina and upgraded to 5.0.1, I noticed that the performance when using USB has taken quite a hit. My bottleneck is an USB to serial converter that I need to use to talk to some embeddded hardware, and it uses software that does a lot of polling on the serial bus. Compared to my old MacBook and Fusion 4 operations now take 35% longer.
I wonder where the performance hit comes from, is there extra translation needed between the USB chip on the MacBook and the chip simulated for the virtual machine?
It is something that I would really like to see improved.
