PSU problems

[Moriath]

I think my psu is a little weak for my system as the 12v rail was a bit under the recommended amps for my gfx card and i get some stability problems

Trouble is I cant find any where reliable that will tell me the amps on the 12v rail all the shops just go on about 600watt psu etc etc

I need at least 20 would prefer 22 amps or more on the 12v rail preferably dual 12volt rails as well for added stability

Anyone can recommend a good psu that isnt going to cost me an arm and a leg ?

Cheers

 

[inactionman]

Depends on your definition of arm and a leg!

I'd suggest the Corsair 620W, (http://www.scan.co.uk/Products/ProductInfo.asp?WebProductID=446787). Based on the Seasonics, and they are great. Nearly a hundred quid though, but with PSU's you definitely get what you pay for!

 

[Kryten]

600watt is probably overkill unless you're on an SLI setup and RAID.

You can still get decent for 40-50 quid if you shop around. ANything from seasonic, enermax, antec or akasa to name a few should suit.

It's not really a case of how many "amps" the 12v rail handles any more, thankfully. The 12v rail used to handle everything on the system that ran at 12v - most modern systems and PSU's have 2 (or more) 12v rails, separating your drives from your CPU for instance - eliminating that problem entirely.

So, any ATX 2.2 compliant PSU will suit, but please don't buy cheap - the PSU is the most important part of your PC and has the power to literally explode any part you can think of.

Couple of links:

http://www.scan.co.uk/Products/ProductInfo.asp?WebProductID=465717
http://www.scan.co.uk/Products/ProductInfo.asp?WebProductID=408083

Hope thats of some help.

 

[Skyler]

There isn't much difference between a low quality PSU and a good one (price wise), when you consider how long a good one will last and all the other factors.

 

[Moriath]

Thanks for the help .. i ordered a corsair one from overclockers cause the scan delivery was going to take a week heheh

I went for a 620 one as I guess you can never have too much power and I read a very good review of it.

Just have to wait for tomorrow and delivery day to see if it solves my problems

 

[inactionman]

Good buy.

I always recommend a 600W PSU, why? Energy efficiency, as they are rated higher they will cost you less to run (as they should never have to run in the inefficient range of supply, saving you money on electricity in the long run.

And people might want to avoid the Hiper's these days, numerous reports of them failing after a year or so (and sometimes taking components with them), but that may be as they were so popular (i.e. the more something sells, the more failures you'll hear as people who have something to complain about tend to scream loudest!).

 

[Kryten]

Agreed - I've been hearing more and more. I personally still think this is a byproduct of the gimmicky modular designs. Modular PSU's are even more case restrictive than normal ones and just gives something else to go wrong.

As with all electrics : the less unnecessary connections, the better.

 

[Tom]

They won't tell you 'the amps' as they can't possibly know what you're going to connect to their power supplies. The wattage figure however does give you the information you need.

You need to know precisely how many amps the equipment is going to draw from the power supply, and that includes keyboards, mice, etc. Disregard the monitor as for the most part it has its own power supply. And looking at the individual power ratings for each piece of equipment, and the voltage it requires, will tell you.

For instance, a 10W device being fed 12V will draw 10/12 = 0.83r amps. A 45W device on 12V will draw 3.75A.


Power = voltage * current

Current = power / voltage

Voltage = power / current



The easiest way to look at this is just to find out how many watts the power supply can deliver. Then you add together the wattage requirements of every device you are going to connect to that power supply. If the former exceeds the latter, then provided that you've accounted for the different wattage capacity of each output (ie power cable) on the power supply (as they will add together to supply the total wattage) you'll be ok.

 

[Moriath]

But trying to match all that against gfx card requirements of certain number of ampson 12volt rails gets to be confusing mixing watts and apms

Still the corsair has 3 12v rails which should be good enough

 

[Tom]

Its not at all confusing.

All electrical devices will have a power consumption rating written on them somewhere.

All you need to know are the equations above, and that power supplies do not 'supply' current. Current is drawn from the power supply. Thats why when you look at PSUs, they won't quote anything to do with amps, because until you attach something to them, its meaningless.

Use the equations I gave you, its very simple.