What is a good trusted PSU calculator to use?

[reyrey761]

Im planning on putting a new GPU in my current rig, i'm not sure how much power I will need so I need a trusted PSU calculator, any suggestions?

[jim]

Most of them are useless, I don't know of a good one. The best way I've found it to find a review of a similarly spec'd machine, and see what the reviewer found typical / peak power usage to be.

If you let us know what your rig is, what the proposed GPU is, and what PSU you have we can probably advise better. One of the most important things is the brand of the PSU, because that indicates the quality. Power alone isn't a very good indicator.

[reyrey761]

I know of course to use a trusted PSU, that's why my current one is a corsair cx430w PSU, I'm currently using an AMD athlon ii x4 640, 1tb hdd, 4gb ram, and a sapphire hd 7750 but am planning on upgrading to 8gb ram with a radeon r9 270x GPU.

[herulach]

A 430W will be fine with a 270x.

[KeyboardDemon]

A 430W will be fine with a 270x.

I thought that a 500w PSU was recommended for a 270x, I remember that being the case for a standard 270 anyway.

[kalniel]

I thought that a 500w PSU was recommended for a 270x, I remember that being the case for a standard 270 anyway.

Recommended in the sense of not actually any relation to sensible PSUs, but attempting to account for aweful PSUs that can't provide half their rated wattage. The 270 doesn't need anything like a 500W PSU.

OP, as mentioned, avoid PSU calculators. Find reviews for the graphics card that a system as close to yours as possible (or a more demanding system) and see what figures they are getting in the real world.

[MrRockliffe]

I ran an overclocked and overvolted 7850 on a 450W antec PSU without any problems. Best power calculator is common sense really. For any given system with a single GPU and a couple of hard drives, 550W is more than enough (550W would be fine for a 290x and an i7 for example)

[pastymuncher]

None of them really. A good quality 550w psu will be more than enough for just about any single card setups. Pay attention to what the psu is capable of on the 12v rail and ignore the wattage sticker on the side. Take your CX430 for example. Depending on what version you have it is only capable of 336w or 384w on the 12v rail. The rest is made up on the minor rails where it's not really needed. Any decent modern psu should be able to deliver near enough all of it's stated output on the 12v rail.

What card are you looking at getting?


***Edit*** Now that the thread has been merged and I have gone from 1st to 7th reply it makes my post redundant. Your CX430 will be fine with a 270X.

[peterb]

Thread from General Discussion merged with this one.

[MrRockliffe]

None of them really. A good quality 550w psu will be more than enough for just about any single card setups.

Don't confuse single card with single GPU You couldn't run a 295x2 off a 550w PSU

[kris88]

I see a lot of cases come with a PSU included, some even rated quite highly (400W+). Why are these so cheap? would they be loud, or would they use more electricity to produce the same wattage as a better PSU?

[MrRockliffe]

They use cheaper components inside, and thus don't last as long, lower efficiency (thus higher heat output, which in turn reduces life span) and a number of other things. They often advertise more of a peak output rather than continuous operating wattage, which is why manufacturers of components over-estimate (like in many real life scenarios) , just so that a customer cannot complain that his 10 pound 500w PSU blew up when he tried gaming with a 780 Ti (where as normally a solid 500W PSU is enough to power most single GPU systems).

In all, you get what you pay for. They use much cheaper components which lead to the above situations. It's easier to say that 450-550w for most single GPU systems (depending on CPU etc) and 700W and above for multiple GPU systems. In reality, even 3x 290X probably doesn't draw much more than 1000W in a consumer system, but the higher the wattage, the more efficient it'll run (within reason; 40-60% of the total wattage potential should give you max efficiency and least heat and thus noise output)

If anyone notices mistakes in my comment, please feel free to address them. It's quite late and there's a good chance I didn't explain something clearly or have made something up entirely (yes it's only 11, but that's really quite late considering I've had 8 hours over sleep since Friday, not due to going, out may I add, either)

[pastymuncher]

Cheap psu's are garbage and the best place for them is in the bin. They will never get anywhere near their stated output (most make it up on the minor rails where it's not needed, the 12v rail is the important one), cheap components inside, very innefficient and when they go bang they are more likley to take other components with it. Ignore the wattage on the side saying 400w/500w etc in big numbers and pasy attention to what it can actually deliver on the 12v rail. This does not just apply to cheap psu's as some of the psu's from the likes of Corsair, BeQuiet, EVGA and others have models with weak 12v rails. These are also good reasons to avoid cheap psu's:-

Death of a gutless wonder

Death of a gutless wonder II

Death of a gutless wonder III

Death of a gutless wonder IV

Death of a gutless wonder V

[pastymuncher]

Don't confuse single card with single GPU You couldn't run a 295x2 off a 550w PSU

If you look at my post I did say, "A good quality 550w psu will be more than enough for just about any single card setups."

Common sense should prevail and people realise that a bigger capacity psu is needed for a dual gpu card. They should always check reviews of cards anyway to see how much power they actually draw.

[kris88]

They use cheaper components inside, and thus don't last as long, lower efficiency (thus higher heat output, which in turn reduces life span) and a number of other things. They often advertise more of a peak output rather than continuous operating wattage, which is why manufacturers of components over-estimate (like in many real life scenarios) , just so that a customer cannot complain that his 10 pound 500w PSU blew up when he tried gaming with a 780 Ti (where as normally a solid 500W PSU is enough to power most single GPU systems).

In all, you get what you pay for. They use much cheaper components which lead to the above situations. It's easier to say that 450-550w for most single GPU systems (depending on CPU etc) and 700W and above for multiple GPU systems. In reality, even 3x 290X probably doesn't draw much more than 1000W in a consumer system, but the higher the wattage, the more efficient it'll run (within reason; 40-60% of the total wattage potential should give you max efficiency and least heat and thus noise output)

If anyone notices mistakes in my comment, please feel free to address them. It's quite late and there's a good chance I didn't explain something clearly or have made something up entirely (yes it's only 11, but that's really quite late considering I've had 8 hours over sleep since Friday, not due to going, out may I add, either)

Thanks for that. I was considering getting this: http://www.currys.co.uk/gbuk/computi...91337-pdt.html

(I have a £10 voucher so would essentially cost me £50). Is there a better bet at the £40 price-point? thanks

[MrRockliffe]

It depends what you're after, and what specifications you currently have. What's your current system?