FSP 450W vs FSP 500W

[TurdBurglar]

I've been trying to figure out why the FSP 500W would be a better choice over the FSP 450W when the 12V rail specs seem to be worse on the 500W.

FSP 500W 12V1 15A 12V2 15A Max amperage over both rails 30A
FSP 450W 12V1 18A 12V2 18A Max amperage over both rails 32A

Why would the price be $30 more for the 500W? For a new core2duo build, it appears that the 450W would be the better choice. Any insight would be appreciated.

 

[TurdBurglar]

bump

 

[doolittle]

Well you really cant combine them to find max +12v, the AX500 rates +12v draw at 17.5a max/peak for per rail and 15 and 16a for combined max of 31A / 372w. The AX450 is rated for 348w / 29A max.

Also the newegg price is not the best deal on the AX500 it can be had for $67 ($78 shipped) from ewiz that should help flatten out the price difference.

The AX500 is more about aesthetics really - the blue color, sleeved wiring and zero-force connectors are a nice touch. For the budget build go with newegg's ax450.

 

[TurdBurglar]

Aesthetics seemed to be the only conclusion I could come to. Like you said, the extra 2.5A on the 12V rails is available as well.

 

[TurdBurglar]

I was aware that the max wattage supplied to both 12V rails limits performance in many cases, but this information is sometimes hard to locate. It is not always on PSU labels, and I could not find it for the 500W PSU so I was estimating. I apparently just miscalculated for the other.

However, I don't see how the 500W PSU can supply 37A to each rail when the max amperage available on each rail is 15A.

???

 

[TurdBurglar]

I realize it's not 37A on each rail... but combined, 15A + 15A is 30A. So my hangup is that even if both rails are maxed out at 15A, the max amperage on both 12V rails would have to be no more than 30A... right?

 

[Guest]

I think he didn't get the right wattage...

Link

285W max combined: 24A combined.

Here's a quote I found Here

I believe the AX450-PN is not capable of 18+18A output on 12v1 and 12v2 simultaneously. The total +12v output is limited to 348w, which is 29A max. Each individual rail can do up to 18A but not both at the same time. You can do the math for the different combinations.

Also, the AX450-PN is capable of 29A max but that's not to say that it could sustain 29A max for an extended period of time

The AX500-A is capable of sustaining 30A. I feel the AX500-A is an underrated unit, and is more capable of the 18A on each rail than 15A but I haven't the tools to test one with.

 

[TurdBurglar]

That makes far more sense to me. Thanks for the links.

 

[Guest]

You're welcome, I think I would go for the 500W, the price is decent and FSP does underrate their PSU. Should be solid for a C2D with a good vid card.

 

[TurdBurglar]

Already done.