Home Forums Peripherals & Multimedia Peripherals USB 3.0 speed and other queries

For the sleep and fan issue, I have two thoughts:

Have you opened the computer and checked for dust accumulation? That could cause heat buildup, thus making the fans go at high speed and interfering with sleep.

My Mac Pro had a sleep problem, albeit a bit different. It would sleep but then refuse to wake, not all the time but enough to cause concern. I got a blinking power light (about once a second) and the only thing that I could do was to force a shutdown by holding the power button. Resetting PRAM did not cure it.

I replaced the internal backup battery a few weeks ago, and the problem has not reappeared. That may be coincidence, but that's what happened.