My computer is stuttering

[ShnizleGhost]

As of late, my computer has been stuttering. Audio, video and controls will sssssssstttttuttter for about a second. Its becoming once a day where it stutters for about 3 seconds. A while back when I used more than 4 USB ports at once it would shut off the power and data to all but 2 USB ports. It has since stopped doing that.

 

Gigabyte ga-z77x-ud3h bios rev 1.1 (1.2 being the newest)

i5-3750k (not oc'd)

MSi 660ti (not oc'd)

 

Any ideas? The last time this was happening, my PSU was dying, and by the time I had figured it out it was too late. How would I test my PSU?

[XTankSlayerX]

What's your PSU?

[ShnizleGhost]

Corsair 500CX

[ShnizleGhost]

Computer shut down by itself, when it came back on I tried throwing the BIOS update on a flash drive. Windows would only accept the flash drive as a valid device when plugged into one of the two ports that I was talking about earlier. Everything else wasn't complete shut down but nothing I plugged in was valid in windows eyes. Updated the BIOS.

 

I had noticed the stutters only happened when I clicked or pressed a key, so my guess is there was something wrong with the BIOS and USB ports. Hopefully this fixes it.

 

Will update.