OK, I'm upgrading my house server after 10 years. MSI B85M-P33 and Core i5, blah blah. Now I have some old 350W ATX 1.X power supplies (with the 10 pin P1 and the 4-pin 12V P2, supposedly can do 15A at 12V) lying around - the question is not "will they work" because the answer is "it depends!"
The question is - where does one find power requirements for the mobos? Do "modern" mobos like the LGA1150 ones only use 12V? Do they evenly distribute 12V received via the P1 and P2 connectors over the entire board? Do they still use 5 and 3.3 at some substantial number of amps for the CPU if it is provided?
Here's what I do know: The real constraint is the # of pins in the connectors. (My PC is lightly loaded, only one disk, no external GPU, etc.) The difference between the 20 and 24 pin ATX connectors is an additional pin for 3.3, 5, 12, and GND. But there is only one 12V pin in the 20-pin version, and your basic cheap-ass Molex pin is rated at about 8 A, derate that to 5 for the usual cheapness in components, and you're goign to have a smoking hole where the 12V pin in the 20-pin connector used to be in the mobo. But - assuming the mobo uses all 12V pins in the P1 and P2 connectors, and some of the 5 and 3.3 for - what, the CPU? - it should be fine.
Any war stories? I guess the only way to find out for sure is to fire it up and keep an eye on the connectors with one of those remote IR thermometers.....
-wsanders at wsanders dot net
The question is - where does one find power requirements for the mobos? Do "modern" mobos like the LGA1150 ones only use 12V? Do they evenly distribute 12V received via the P1 and P2 connectors over the entire board? Do they still use 5 and 3.3 at some substantial number of amps for the CPU if it is provided?
Here's what I do know: The real constraint is the # of pins in the connectors. (My PC is lightly loaded, only one disk, no external GPU, etc.) The difference between the 20 and 24 pin ATX connectors is an additional pin for 3.3, 5, 12, and GND. But there is only one 12V pin in the 20-pin version, and your basic cheap-ass Molex pin is rated at about 8 A, derate that to 5 for the usual cheapness in components, and you're goign to have a smoking hole where the 12V pin in the 20-pin connector used to be in the mobo. But - assuming the mobo uses all 12V pins in the P1 and P2 connectors, and some of the 5 and 3.3 for - what, the CPU? - it should be fine.
Any war stories? I guess the only way to find out for sure is to fire it up and keep an eye on the connectors with one of those remote IR thermometers.....
-wsanders at wsanders dot net
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