PSU Selection

i built my computer a while ago and got a case+psu for about £30 as i didn't have much cash.
this psu seems unreliable and a bit loud, and now i have cash i want to upgrade :)

i wanted to spend just £30 on it but here is what i have selected as potential winners.
http://www.ebuyer.com/product/152505 - OCZ 400W StealthxStream -£35
http://www.ebuyer.com/product/150985 - Corsair 400w CX - £38
http://www.ebuyer.com/product/166784 - Be Quiet Pure Power 350w - £30

my system has a AMD 550 phenom II, 2x2GB 1066ghz ram, Mobo+onboard graphics, 2 SATA HDDs, 1 DVD-RW. so ye any of those are powerfull enough to power my system. i haven't overclock, but the 350 should even be enough if i decided to ye?

first i had only chose the be quiet but took a look around again, just because i don't know if it would be reliable, if you know it is please say.

they all have fans at the bottom, my case does not allow a fan to be placed in another position, so if you have any suggested PSUs please keep this in mind.

thanks for the help, and make sure to enter the poll aswell :) makes it easier.

BOUGHT THE CORSAIR. THANKS ALL. I WILL POST A REVIEW UP TOMORROW TO HELP ANYONE ELSE WHO IS CONSIDERING THE CORSAIR
8 answers Last reply
More about selection
  1. It's a good idea to buy a PSU that's about twice the capacity that you expect to need. This is because PSUs are generally most efficient at about 50% load, and this means that for the same load a power supply with a twice the required capacity will draw less power from the wall socket than one which is running at 100% capacity.
  2. good tip cheers. i did notice that on a little graph i saw, didn't think about this though.
    400w is more suitable then, keeps it efficient and allows future OC to be a bit efficient too.
  3. sorry have to double post as the system won't let me edit.

    i've done some more reading and the ocz is more efficient, but slightly less powerful, power will not play a role anyway so i'm going for the ocz soon as it is in stock again but i have another thing i'd like to ask and might aswell just put it here as it is related.

    i am considering if i need a cpu cooling fan too.

    my system heats up alot right now.
    40C - PSU idle
    30-35C - CPU - standard use

    70C - PSU under a stress test
    55C - CPU under stress test

    my CPU isn't overclocked. it is more than powerful as it is. using the stock AMD 3 CPU fan from my 550 phenom II.

    will the PSU automatically make it so my CPU runs cooler too? or will i need a CPU fan for that? and is it worth getting a fan for it?
    if so please suggest one from ebuyer (i want to get over £50 anyway for free delivery).
  4. You definitely need a CPU cooling fan!!!!

    The PSU has a fan and that's an important part of moving air through the case. But you would normally use one or 2 more fans in the case as well, and a CPU heatsink and fan is absolutely essential on modern CPUs.
  5. sminlal said:
    You definitely need a CPU cooling fan!!!!

    The PSU has a fan and that's an important part of moving air through the case. But you would normally use one or 2 more fans in the case as well, and a CPU heatsink and fan is absolutely essential on modern CPUs.


    my case is a bit weird, the case contains the psu at the bottom front corner, and uses a case fan faing the psu fan to cool, it was meant to be supplied with another 6cm fan but wasn't.
    i have ordered 2 6cm case fans with my psu. along with a wireless pci card.

    as i've just spent £50 today i'll give it a go first and if the cpu temp isn't effected much i'll take a look into a heatsink and fan. only wanted to spend 30 on the psu and that's it :p o well.

    ps. i ordered the corsair as the ocz has been discontinued at ebuyer.
  6. What kind of CPU have you got? Most of them come with a stock heatsink and fan - that should be adequate. But if there's no heatsink & fan then the CPU will likely overheat in the first few seconds and shut down the system.
  7. using the stock AMD 3 CPU fan from my 550 phenom II.

    it's quite a beefy heatsink and the fan has a vent hole opposite in the case to allow it to throw out the air easy.
    thanks for the help sminial. and thanks for the votes to everyone else.
  8. ok, this psu is completely silent!

    i also connected 1 of my 2 6cm fans, which are very loud i would have to say at about 40dB but this makes my CPU and PSU at <30C idle, compared to 40-50C with my old PSU and no extra case fan.

    now my only choice is to find a program to control my fanspeed for molex connected fans which i am pretty sure there won't be, try to manually limit their speeds to a low noise speed somehow lol or just chuck them.

    i think they are being over powered with my psu and are going crazy fast or something, because almost everyone on ebuyer said they were very quite. this right now is louder than my old PSU.

    so if you have an idea how to slow my fan speeds i'd be grateful.
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