On Tue, 14 Dec 2004, Guy wrote: > My disk drives are rated to use 19.1 watts while active. > My disk drives also get very hot without forced air movement. > 14 such disks use 267.4 watts. That would give you 152.6 watts for > everything else. I bet your disks use less power than mine. I agree with > Michael, you may be exceeding the power rating of your power supply. an overworked power supply will fail "faster" for "wattage" ... using a sharp needle, "pop" ... that is NOT how "wattage works" - for a given voltage, you should be operating at 1/2 of its rated amperage - at 12v ... what are the disks rated at for power up ( spinup ) vs ambeint normal operation - typically 1A to power up and 0.5A for normal spinning operation for a powersupply rated at 12V for 10A .. you can run 5 disks if you run more disks ... your power supply will die faster and/or your data gets corrupted during power ups when the system and the drives think you're in "normal operation" and enables write while in fact, its is still in its bootup > Also, I would not want to push a power supply to the max rating. It should > be sized 50 watts or more beyond what you need. make that 2x the total wattage needed by the system .. NOT 50W - add up the amps needed on the 3.3V, 5V, 12V - use the MAX needed for operation, which is the power up sequence to get a "random number" of operating current .. Total watts == 12 * 12v(maxcurrent) + 5v * 5v(maxcurrent) 3.3V * 3.3v(maxcurrent) - normal operation usually does NOT need as much current - switched power supplies can output higher current than it is rated at, but it will not be able to sustain that "extra current load" for more than a few seconds before its over-current circuitry kicks in to shut itself down - you will be bouncing up and down in current on each power line till the system is all booted - put a digital storage scope on the 12V and 5V and 3.3V line and an ampmeter on each power line and watch it go bonkers c ya alvin - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
