Building a PC - need help choosing a PSU rating

[coastercrazy10]

Hey all,

Putting together a PC this summer and I've just about finalized everything. I've chosen a PSU even, but i'm concerned it won't supply enough wattage and I don't want to have to buy two Power Supplies. Here are my prospective specs:

i5-2500k Intel Quad Core
ASUS P8P67 Motherboard 1155 socket (sandy bridge architecture)
EVGA 460 gtx GPU SE (Fermi) (01G-P3-1366-TR)
Caviar Blue SATA 6 Gb/s 1 TB HDD (WD10EALX)
Blu-Ray drive/burner (haven't quite decided yet)

Here's the case (normally doesn't matter but it has 5 integrated fans so it will definitely draw at least some power...)
http://www.newegg.com/Product/Product.a ... 6811517006

Now I'm looking at the OCZ Fatal1ty series since they have red fans and LEDs which would match my case. Trouble is I can only find a 550W and a 750W PSU. I have no idea if the 550W would be sufficient for this machine, so I'm trying to decide if it's worth spending the extra bit of cash. I am planning on overclocking my CPU at some point so keep that in mind...I'm leaning towards the 750W to allow for possibly running SLI later on, but I just want some opinions on if the 550W would be okay.

Also if you have any suggestions about any of the parts I currently have picked out/experiences with them, please share them with me. This is my first build and I though I've learned a lot I'm still learning a ton. Just don't wanna get stuck with something that's crap quality.

-Ben

[irixith]

A high end core i5/i7 system with a graphics card should have a minimum of 600W. I've just built a Core i7 2600k machine with a Seasonic 660W 80+ Gold certified power supply myself. Anything under 600W and you could be looking at trouble, even if the wattage calculations tell you different.

I'd definitely recommend the 750W if you've got your eye on that, but moreso an 80+ Gold certified unit. Remember that your components will only draw as much power as they need, and that clean, efficient power is important.

[coastercrazy10]

OK, I can do that.

Another question though: what is the significance of a single-rail? It's +12V which is what I need, but some PSUs I've looked at say double-rail, while others say single. What does that affect and is it something I need to consider for my setup?

-Ben

[irixith]

Read up on single vs dual rail here. The short version is that it's immaterial if you're buying a proper quality power supply.

Don't cheap out on your power supply -- look at power supplies in the $200 range, and see what features they're offering over their cheaper brethren to help understand what's important and what isn't. Then, wait for one of the $200 power supplies that you've chosen to go on sale. (Mine cost me $149 in Canadian funny money, and is one of the more expensive components of my system.)

[coastercrazy10]

Alright, well I did a bit of searching and came upon a nice modular 750W PSU
http://www.newegg.com/Product/Product.a ... 6817207003

It's about $160 normally but newegg is awesome and offers it for $110 after rebate. Seems to fit the bill. Only problem is that it doesn't match my case but if that's the only issue I think I can get over it lol. This seem like a good option?

-Ben

[s1mplehumar]

Read up on single vs dual rail here. The short version is that it's immaterial if you're buying a proper quality power supply.

Don't cheap out on your power supply -- look at power supplies in the $200 range, and see what features they're offering over their cheaper brethren to help understand what's important and what isn't. Then, wait for one of the $200 power supplies that you've chosen to go on sale. (Mine cost me $149 in Canadian funny money, and is one of the more expensive components of my system.)

While I agree on not skimping on a PSU, defaulting to a $200 unit is just poor planning or shopping, imho. With a little patience you can grab a competent 700+ watt PSU for under $100.