PSU Overkill

Smorgasbord · 30 Nov 2008 at 15:59

Hello,

Quick question, is the PSU I have overkill for my system? It is a CoolerMaster 520W Modular, and the system I have probably doesn't use half of that?

If so, would i be better getting a lower power consuming PSU?

Cheers,

Malazan · 30 Nov 2008 at 16:02

Smorgasbord said:
Hello,

Quick question, is the PSU I have overkill for my system? It is a CoolerMaster 520W Modular, and the system I have probably doesn't use half of that?

If so, would i be better getting a lower power consuming PSU?

Cheers,

No it's not overkill.

There's no such thing as lower power consuming PSU, or a higher power consuming PSU for that matter.

If your system requires 300W, the PSU supplies 300 watts, whether it's a 500W PSU or a 1500W PSU.

Duke · 30 Nov 2008 at 16:03

520w is the max it will output (well most are about 90% efficient so a bit under that), so getting a lower rated PSU won't make any difference. It is the amount of power the components consume that matters.

Smorgasbord · 30 Nov 2008 at 16:11

Nice one guys, thanks a lot.

Malazan · 30 Nov 2008 at 16:28

Smorgasbord said:
Nice one guys, thanks a lot.

You're welcome.

shadowscotland · 30 Nov 2008 at 16:36

Duke said:
520w is the max it will output (well most are about 90% efficient so a bit under that), so getting a lower rated PSU won't make any difference. It is the amount of power the components consume that matters.

Most are no where near 90%!!!!
MOST psu sold are under 80% in use
ALL good ones should be 80plus certified and are between 82% and 86% at around 45-50% load (but still above 80% at 20% and 80%).

the best 1000w psu powering a high spec office pc (150w so 15% load) will be at 81%
That's 185w at the wall
the best 300w psu powering same system (150w so 50% load) will be at 92%
that 163w at the wall

Over sizing a PSU only costs you money due to reduced efficiency.

So to answer the opening question - if your psu actually uses half your power need it's perfect

buy/borrow a plugin wattmeter - most people are amazed at how little a pc actually uses - my oc'ed e6600/IP35pro/4gb/Raptor/8500gt/watercooling is only 120w @100% load.
(or shocked that their SLI rig uses more in an hour that there fridge does in 24!)

Edit: based on your sig - your pc when gaming is well under 200w - Antec earthwatts 380w psu or Enermax Modu 82+ 425W if buying new

gareth170 · 30 Nov 2008 at 19:18

shadowscotland said:
buy/borrow a plugin wattmeter - most people are amazed at how little a pc actually uses - my oc'ed e6600/IP35pro/4gb/Raptor/8500gt/watercooling is only 120w @100% load.
(or shocked that their SLI rig uses more in an hour that there fridge does in 24!)

my Zalman ZM-MFC2 says my system using 345w at full load lol.