> lifetime maybe be ten thousand (or less) hours...barely enough to last a full year of 24x7 operation. Wait, how many of these are in a typical consumer compu

> lifetime maybe be ten thousand (or less) hours...barely enough to last a full year of 24x7 operation. Wait, how many of these are in a typical consumer computer? Even if it's just 20 or so (I truly have no idea) I don't get the numbers to add up. I've run, say, 6 computer-years worth of capacitors with no problems -- under the assumption above this would be 120 capacitor-years. Let's say at this point there's a 50--50 chance I would have experienced problems (this is not a rigorous survival analysis, of course, just something to get started). If a single capacitor has a lifetime of just one year, then "lifetime" must be defined as the solution to p^120 = 0.5 which is p=99.5 %. Is it correct that when one speaks of the "lifetime" of capacitors one refers to the point where 0.5 % of them no longer work? If "lifetime" means 50 % no longer work then I would seem to have been extraordinarily lucky (I'm the 10^-35 %!!) -- I don't hold that for very likely. What else am I missing?