
if these questions sound silly and stupid please forgive me, im not much of a computer guy so... let me apologize ahead of time

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I noticed that a lot of PSU's usually have a fan located on the back near the plug that connects to the power outlet but there are many that have fans located on the top of the psu's also...

well... my question is would you need a case with a rear top fan if that were the case?

or could you simply turn it upsidedown and let the side and rear fans take care that?
If a case would happen to have a lot of fans, a side, rear and top fan, what would it rely on for power/ability for use?

From what I know a fan has 2 wires/cord'thingy'majigs that connect to the computer, one for the psu and one for mobo, right? are fans power cord directly connect to the psu or are both connected through the mobo? do all mobo's come with sockets that support multipule fans or is there term/component I should be looking for? especially the case for old mobo's that connect to semperon or amd 64
back to psu's, i've got the point that +12v rails are standard for all good mobo's but when the term dual +12v comes into play I get a bit confused

. If a mobo is a +12v then can it be connected to a dual + 12v Psu? especially older mobo's that go with amd 64 or semperon.
What are the terms SLI Support, Approvals V TUV, UL, CUL, CE, CB, FCC terms all mean?
Hehe i know my questions are a bit fustrating to answer

but it be really appricated if someone could walk me through it
