Upgrading this computer, should I upgrade the power supply?

Well I've finally wore the skipper down and I've received a signed purchase authorization to buy replacement parts for my main PC.

I built this one in 2008. I'm upgrading from a 2.66 dual core Intel, 4 gigs of ram and a geoforce 8800 to a 3.4 ghz quad core Intel cpu, 16 gigs of sdram and a 2 gig 7850 radeon.

My only worry/issue is that I'm running a 400W power supply and the video card "suggests" a 500W and 2 6-pin connectors. My PS doesn't have a 6-pin connector, I'll have to use the "pass-through" to power it. My current PS is a sparkle 400W, very nice quality but I wonder if it will be enough.

Any thoughts? Hoping those of you with newer video cards will have some intel.

Tim

Personally, I've been running a 600W+ power supply for around three or four years now.

Honestly I do think 400W is on the low end of what you need to run for a pc with the expectation of running a moderate- to high-end graphics card. Radeons in particular tend to draw more heavily from the PSU than equivalent GeForces, and I run the latter usually.

I would be very hesitant to run a PSU below the listed "requirement" (which usually has some wiggle room, to be honest). I'm not really strong on the electrician side of things, so I'll defer to someone with more technical expertise on that than me.

So when I RMAd my Seasonic power supply, I used my wife's 500w PSU. To make sure I wasn't overusing it, I plugged my computer into my Kill-A-Watt meter and I was very surprised I never went over 310 Watts while paying games. It also never went over that when I was running intel burn test AND fur mark at the same time.

Here is what my I was using hardare wise at the time:

AS rockextreme 4 Mobo
3570k
560ti
16gb ram
SSD boot drive
1 TB file 7200rpm drive

I was not over clocking. My thought is get anything 550w and up. computer parts are much more power efficient than they ever were but I would spend the little extra money for some headroom. 400w is just cutting it.

I'd upgrade, though as others have said, you really don't need a ton of power these days. Get at least a Bronze certified PSU to help with that power bill, too.

I would recommend keeping above 600W, myself.

You will also need to decide if you need single rail or modular. I prefer single rail myself and I saw this one on Newegg that was on sale atm.

http://www.newegg.com/Product/Product.aspx?Item=N82E16817139020

cartoonin99 wrote:

I would recommend keeping above 600W, myself.

I think it depends upon two things. Firstly is your demands, obviously. You don't want to undersupply a demanding PC with a weak PSU, but you would also be throwing money away by running a low power system with a 1kW PSU. Secondly is under what demand your PSU is most efficient, because different PSUs are most efficient at different points. Sites like PC Part Picker have a built in guide to what you should need.

I'm sure there's a good Malor post around here somewhere talking about single/multiple rails, and what rail feeds which type of component (ATX, PCIe, etc).

Modular supplies usually refers to being able to only add the cables you need so it's easier to keep tidy.

What Scratched said is important, you don't want to be running at 65% efficiency and wasting a ton of energy. If your psu is from 2008 I'd probably replace it with the new rig since the last thing you want is an old psu killing your brand new pc parts.

NewEgg has a PSU calculator.

Anything JohnnyGuru.com recommends is a good way to go.

I think it depends upon two things. Firstly is your demands, obviously. You don't want to undersupply a demanding PC with a weak PSU, but you would also be throwing money away by running a low power system with a 1kW PSU. Secondly is under what demand your PSU is most efficient, because different PSUs are most efficient at different points. Sites like PC Part Picker have a built in guide to what you should need.

True enough. In my case I tend to future proof though and put money towards a quality psu with the idea that I will be upgrading the GPU, more ram, etc, sometime in the future.

If I am lucky enough to still be using the psu, I can possibly put it into a new build a few years down the road.

What you want to do is count up your required watts from the various components, and divide by 12. Why 12? Because almost all power in a computer these days is pulled from the 12V line. There's a little bit pulled on 5V, usually by hard drives, but assuming you have the usual 1 or 2 and a CD, all you have to think about is 12V.

So, in your case, you've got an Intel CPU, which will need no more than 95 watts if you're not overclocking it. (I like to plan on about 150-175 if you're going to OC.) The motherboard and memory will need about another 25 watts. And then you've got the 7850. It's hard to find exact numbers on that, stupid AMD doesn't give an actual specification that I can see, but reviews seem to call it 125 watts under load, baseline. (also not overclocking).

So, you need 120 watts for the motherboard, and 125 watts for the card. Divided by 12, that's 20.4 amps.

That's really not much. Any single-rail supply you can buy will handle that. Your Sparkle 400 is probably not single-rail; it's probably dual-rail of 18A or so per rail. Assuming that the unit splits the two rails between the motherboard and the video card, it should work okay. But you need to know exactly where those rails are going. Since you're going to be using an adapter, you could potentially end up with both units on the same rail, and that would almost certainly be too much.

You'll need to look at the label on the side of your supply to see the overall ratings. You can take a picture and post it here, if you need help interpreting it. Finding out which rails are wired where, however, is something I don't know how to do. The owner's manual might tell you, if you can find it online. If it does have two rails, which most inexpensive supplies do, then you really, really shouldn't wire both your big-draw items on the same rail. It might work okay, maybe even for a long time, but it could also blow up spectacularly, and losing a power supply can kill everything else in the computer.

If you can't puzzle it out, or don't want to risk it, a nice basic Corsair 430CX will work beautifully. It's single-rail, so all the power is on all the connectors. You don't have to worry about anything, just plug everything in, and go.

If you plan on doing a big overclock, and eventually adding a big video card, going up to a single-rail 550 will let you plug in any single CPU and any single video card. But for the hardware you're actually talking about, you only need about 21 amps, which almost any power supply will handle. You could probably run that machine okay on a 300-watt supply, although that might be cutting it a little tight.

We typically point folks at Corsair and Seasonic, but any supply that jonnyguru.com says is good, is fine. If you read the reviews for those brands, you'll see why we recommend them. But they are not the only good options out there, and you might save money with some careful shopping. You could even end up on another Sparkle/Fortron; those are supposed to be very good supplies, considering how cheap they are.

Thanks for all the advice. I have to sit down and really go through my options.

I'm going to upgrade the PSU, as yall have mentioned, might as well make sure I've got plenty of power and do a little future proofing.

Got to take some time and pick out a quality unit.

Thanks again,

Tim