I couldn't tell you who but someone was kind enough to post the calculations. It came out that the 1f should be able to power the mini itx system for 1/4th seccond of cranking. Not enough if you ask me!
I'm a HUGE fane of the seccond battery with an isolator circuit that kills power durring cranking (and in my case engine off aswell). 1fs are expensive too! my rig cost me less than 50 bucks and it can run my computer for over an hour.