Will card work?

The 550ti uses a single 6 pin PCI-E power connector, which is rated at 75W. The card could draw another 75W through the PCI-E X16 slot. According to this:

The Truth About Graphics Power Requirements V2 - Atomic 3.0

a 550ti actually consumes over 150W at full load. If all of that comes from the +12V supply, that'd be 12.5A. That leaves only 5.5A for the rest of the system, given your (rather poor) "500 W" PSU.

It looks like your power supply is not adequate for the 550ti.

If you can consider a replacement, you may wish to look at:

Newegg.com - CORSAIR Builder Series CX430 V2 (CMPSU-430CXV2) 430W ATX12V v2.3 80 PLUS Certified Active PFC Power Supply

(Corsair Builder CX430 V2) or:

Newegg.com - Antec NEO ECO 400C 400W Continuous Power ATX12V 2.3 / EPS12V 80 PLUS Certified Active PFC Power Supply

(Antec Neo Eco 400C). They both list for $45, but there's a rebate on the Corsair at the moment that takes it down to $25. (I dislike rebates, but I use them.)

Thanks for the heads-up, what about these:

1. CORSAIR Builder Series 500W - $59.99
2. COOLER MASTER eXtreme Power Plus 500W - $48.99
Here are some others I was considering.

Do the modular PSU's actually work good & not 'leak' power?

CJW said:

Thanks for the heads-up, what about these:

1. CORSAIR Builder Series 500W - $59.99
2. COOLER MASTER eXtreme Power Plus 500W - $48.99
Here are some others I was considering.

Do the modular PSU's actually work good & not 'leak' power?

Those both look OK. Corsair has a better reputation than Cooler Master, but I don't know who actually makes either of those.

I've read comments about fearing "contact resistance" with modular power supplies. I'm not an electronic engineer, but I think as long as the additional contacts aren't corroded, modular PSUs should be fine. They offer the practical advantage of not having disused cabling. (My current PSU isn't modular, but I didn't choose it for that reason.)

Thanks for all the help so far everyone. I've decided to update my PSU 1st & still trying to narrow it down between these: Fry's, Newegg.

The main sticking point for me is reliabilty of these & if each have the correct connections for my mobo (MSI 785GM-E51). I believe they all do, but my mobo's manual doesn't tell me much. Any suggestions?

CJW said:

Thanks for all the help so far everyone. I've decided to update my PSU 1st & still trying to narrow it down between these: Fry's, Newegg.

The main sticking point for me is reliabilty of these & if each have the correct connections for my mobo (MSI 785GM-E51). I believe they all do, but my mobo's manual doesn't tell me much. Any suggestions?

Your motherboard needs a 24 pin ATX power connector, plus a 4 pin +12V CPU power connector. (Many supplies use 20+4, which can be used with either 20 or 24 pin ATX motherboards without an adapter. There are similar arrangements for the 8/4 pin +12V connector.)

You'd have to buy a power supply that was a really old design to get one with just a 20 pin ATX connector.

Make sure that the PSU you buy has at least one 6 pin PCI-E power connector (or a 6+2 one) for your future graphics card.

All PSU's I'm looking into have the 20+4Pin Main Connector.
Also, 1 4+4-Pin ATX12V/EPS12V or 1 12V(P4) connector; are these 2 the same connectors just stated differently?

I'm leaning towards the Antec Earthwatts EA-650, or either Rosewill's -one has more wattage but other is modular.

CJW said:

All PSU's I'm looking into have the 20+4Pin Main Connector.
Also, 1 4+4-Pin ATX12V/EPS12V or 1 12V(P4) connector; are these 2 the same connectors just stated differently?

I'm leaning towards the Antec Earthwatts EA-650, or either Rosewill's -one has more wattage but other is modular.

Some PSUs have an 8 pin +12V connector and a separate 4 pin. Some have a 4+4 that can be used with either.

I'd take an Antec over a Rosewill.

Just to confuse things, consider:

Newegg.com - PC Power and Cooling Silencer MK III PPCMK3S600 600W ATX12V v2.3 80 PLUS BRONZE Certified Modular Active PFC Power Supply

There's a rebate on it (expires 1/31/2012!).

Thank you for all the help everyone. I have decided on going w/the 550Ti & Antec Earthwatts EA-650 but unfortunantly, other things have come up & I am going to put my upgrades on hold for now.