What sort of wattage do i need for this system?

[razer121]

So i'm building my sister a pc and need some advice! i have a good idea of what i want in the pc so i shall list some specs

Core i5 2500k
msi Matx h77 motherboard
4gb ddr3 1300 - 1600 (undecided!)
dvd-rw drive
no discrete gpu otherwise if i have to due to motherboard limitations then it would be a radeon 4670 HD (think that is what it is) so not a power hogger as it doesn't need a separate pci-e 8pin

So i thought about 400Watts but would that be okay? or would maybe a lower psu be better (energy efficiency and all)

thanks!

[TeeBlack]

400w would be fine for that system. just get a quality psu.

[GeorgeStorm]

400W is more than enough for that system

As Tee said, try to get a good quality PSU, 80+ rated in some form (higher the better)

[kalniel]

Without a graphics card you'd be fine with much less even, but it's hard to find quality supplies rated much lower than about 380W. Go for a quality unit. Ignore 80+ ratings as they're no measure of quality - I'd take a good supply over a generic 80+ gold any day, and at the kind of load it'll be pulling a % or two in efficiency isn't going to make a big difference.

[GeorgeStorm]

Without a graphics card you'd be fine with much less even, but it's hard to find quality supplies rated much lower than about 380W. Go for a quality unit. Ignore 80+ ratings as they're no measure of quality - I'd take a good supply over a generic 80+ gold any day, and at the kind of load it'll be pulling a % or two in efficiency isn't going to make a big difference.

I mentioned it since when I've looked at PSUs the two have always gone hand in hand, I never saw a generic PSU with a decent 80+ rating, nor a decent PSU without a 80+ rating

Maybe I just didn't see them/things have changed recently.

[scaryjim]

Without messing about with non-ATX PSUs it's hard to get much lower than 400W anyway (you can pick up low rated 80+ industrial PSUs in less-common form factors like flexATX (1u) and TFX if you shop around - these rate down as low as ~200W) and with a 400W PSU you're not even going to be pulling a quarter of it's rated load with that build - even if you add the 4670 you're unlikely to pull more than about 150W from the wall. PSUs operate least efficiently at low relative loads, so go for the lowest rated good brand PSU you can get your hands - something like these:

http://www.ebuyer.com/520267-be-quie...-l8-350w-bn221
http://www.ebuyer.com/247713-be-quie...300w-psu-bn103
http://www.ebuyer.com/247714-be-quie...350w-psu-bn104
http://www.ebuyer.com/185183-antec-3...-ea-380d-green

[kalniel]

I mentioned it since when I've looked at PSUs the two have always gone hand in hand, I never saw a generic PSU with a decent 80+ rating, nor a decent PSU without a 80+ rating

Maybe I just didn't see them/things have changed recently.

Nothing's changed - you can still get pretty rubbish PSUs with 80+ rating (eg: http://www.scan.co.uk/products/450w-...an-atx-v22-psu) and good PSUs without (http://www.scan.co.uk/products/350w-...an-atx-v23-psu). Just like you could in the past.

[kompukare]

Never mind 80+ not having much meaning, did anyone see the article computerbase.de did about PSUs with false 80+ lablels?

http://www.computerbase.de/artikel/n...l-zertifikate/
Translated/mangled by Google.

A few cheaper brands like Xigmatek, Xilence and Sharkoon mentioned in that article. While I would never trust any of those but now there's even more reason not to.

[CAT-THE-FIFTH]

A Seasonic G 360W??

[GeorgeStorm]

Nothing's changed - you can still get pretty rubbish PSUs with 80+ rating (eg: http://www.scan.co.uk/products/450w-...an-atx-v22-psu) and good PSUs without (http://www.scan.co.uk/products/350w-...an-atx-v23-psu). Just like you could in the past.

I must have just ignored them without realising, then again I'd look for Bronze as a bare minimum, and I tend to either stick to manufacturers I know, or more likely google for reviews for any product before buying so it's never an issue.

[kalniel]

I can find examples of bronze (and probably silver and gold) supplies that I wouldn't trust either, just picked the first one that I found for example purposes Sticking to manufacturers you know and have researched is a better idea (so you don't go on the 80+ rating after all )

[GeorgeStorm]

I can find examples of bronze (and probably silver and gold) supplies that I wouldn't trust either, just picked the first one that I found for example purposes Sticking to manufacturers you know and have researched is a better idea (so you don't go on the 80+ rating after all )

Well I kind of do, since I don't think I'd buy a power supply now that wasn't well rated on that front

Although just sticking with a manufacturer isn't the best idea either (CX400 for example), as with anything just find reviews.

[dacads]

Grab a xfx 450w for £40. I have had xfx 550w previously and currently their 850w offering

[ik9000]

I think you're in the right ball-park. 450w or thereabouts

You don't want to be too low or too high wattage if you can help it. Most PSUs are most efficient between 50% and 75% load. So if you have too low a rated supply and are running at 95% capacity it could cost you more in electricity bills than a slightly higher rated PSU running at optimum efficiency.

It may be that looking at a 500w PSU with a decent load-efficiency curve opens up more options for you.

And sorry Dacads, based on people's experiences listed eleswhere on this forum, I wouldn't touch XFX PSUs. Nearly bought one once but kind folk enlightened me before I'd placed the order.

[kalniel]

And sorry Dacads, based on people's experiences listed eleswhere on this forum, I wouldn't touch XFX PSUs. Nearly bought one once but kind folk enlightened me before I'd placed the order.

Are you sure you're not mixing up GPUs (plenty of posts) and PSUs (no negative posts that I remember)? The recentish XFX PSUs have been excellent seasonic-based units.

[GeorgeStorm]

Are you sure you're not mixing up GPUs (plenty of posts) and PSUs (no negative posts that I remember)? The recentish XFX PSUs have been excellent seasonic-based units.

I was going to say, I don't think I've heard anything bad about XFX PSUs, not recent ones at least.