Re: XPS 730x H2C loses power / resets / reboots "randomly"...
Try running prime95 if you get a chance. I would still like to see what temps are and if its stable under full load.This could narrow it down a little more.
Also you could try disableing stuff running in the background in taskmanager.
Normal 0 false false false EN-US X-NONE X-NONE MicrosoftInternetExplorer4 I ran Core Temp along with Prime95 it two test runs where #1 was at the non-overclocked settings (3.2 GHz) and #2 at the recommended overclocked settings (3.73 GHz). Both ran for about 18 minutes before I stopped the test and all tests passed (no resets or reboots either interestingly). Here is what I saw as far as temperatures:
3.2 GHz - Maximum core temp = 72 degrees Celsius
3.73 GHz - Maximum core temp = 80 degrees Celsius