I am suspecting my PC to be running low on power, when I try to use an external hard drive (getting random I/O errors after I connect it, not all the time, only when both drives are busy). Is there any easy way to check if the power supply is supplying enough power for all components?
3 Answers
USB can only provide 2.5W per port. I doubt 5W is going to change your PC from being stable to random errors - if it was running that close to the edge of the PSU you'd be getting more issues. Sounds more like a dodgy caddy/controller on the external drive.
Try either testing the drive internally (take it out the box, plug it in with IDE/SATA); or a different external disk.
This site has a power supply calculator that should help you.
You fill in all the parts your computer has and it will calculate the recommended amount of Watts.
Generically, try using a killawatt plug http://www.thinkgeek.com/gadgets/travelpower/7657/
Worth their weight in gold over time.