Do we really need these powerful psus?

Phil2008

Phil2008

Phil2008

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Joined
17 Dec 2004
Posts
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I have a plugin power meter and this is the test I did with my ups pluged in to the power meter. This is whats plugged in the ups and what I had in for the test

My main pc tower (see sig)
2 19" lcd montors (1 on standby)
1 17" lcd monitor (on standby)
Yamaha amplifier
10" sub
2nd pc (on standby)
router
2 external hdd (off)
1 powered usb hub

The test (ups uses about 40watts alone)
223 watts, amp and sub on and playing music from pc
182watts, amp and sub off
263watts, amp and sub off, running furmark
243watts, with amp and sub off, running linx
228watts, with amp and sub off, running orthos
............................................................................................
UPDATED
My 2nd test
PSU plugged into the power meter

105watts, idel in vista
152watts, running orthos
167watts, running linx
169watts, running Intel Burn test v2.2
191watts, running furmark
226watts, running OCCT
270-282watts, running OCCT + Intel Burn test v2.2

So my question is, these insanly high psu's you can buy, is it all a marketing thing, or do we need 750+ watt psus?? Im guessing my 620watt psu will last a few upgrades/builds yet.
 
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Some ppl buy them so that they can deliberately run them under capacity as the PSU will run quieter when running below ~60% load - if you're after a silent system it's a valid enough reason.

But on the whole - most ppl buy more power than they need out of semi-misguided security and future proofing (i bundle myself in this latter group as mush as the first.)
 
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Sapphire HD 3870 = lower power Graphics Card.

Stick a GTX 295 in running furmark and your power consumption would double. :D

Most people will be fine with a 400-600w good quality PSU for a reasonable gaming rig.
 
Yup, its mostly all nonsense. And kit is getting more energy efficient, chances are you'll need smaller PSUs in the future.
 
i bought one because my previous tagan 480 blew up and it had only 28a on the 12v rail so i used a second old sparkle 300w (12v @ 15a) for the graphics

now the corsair 750 gives me both ample amps on the 12v at 70 amps and quietness .. happy i got it even if it has dented my bank balance
 
Probably for benchmarking/testing purposes and marketing of "beast rigs". You know, all those nvidia powered 4x 295GTX SLI setup benchmarks so people see 300FPS in game and buy the card because it's so leet and cool.
 
Is there a cast iron argument for monster psu's no there isn't for the majority of pc user's but then that has never been one of the considerations when buying components. It comes down to two things mainly do you have the money for one and do you feel happy with what you spend that money on. My psu is above what i need but why have less if you can afford a little more, it is purely down to the individual and isn't a point to hold against or for someone.
 
Heres another test ive just done with the PSU plugged into the power meter

105watts, idel in vista
152watts, running orthos
167watts, running linx
169watts, running Intel Burn test v2.2
191watts, running furmark
226watts, running OCCT
270-282watts, running OCCT + Intel Burn test v2.2
 
MikeHunt79 said:
As a rule of thumb, anything above 450W is not needed unless you're running an SLI setup.
Click to expand...


My mate was using a 475w Enermax and that wasn't enough to power an 8800gtx.

Also PSU's can become less efficient with age, there was a chart knocking about somewhere.
 
Phil2008 said:
I also think manufactures rate their psu's higher then what they are?
Click to expand...

not good ones, well not normally. they rate them at their sustained output max, not there peak. Cheap ones will rate it by their peak which means your 550w q-tec can only supply about 350 for more thana fewms without blowing up.
 
F2kSel said:
My mate was using a 475w Enermax and that wasn't enough to power an 8800gtx.

Also PSU's can become less efficient with age, there was a chart knocking about somewhere.
Click to expand...
What PSU brand was it? Hiper PSU's don't achieve their rated wattage for example.

Also, I'd like to see that chart, as that's the first time I've heard of PSU's losing efficiency! :p
 
I bought a 750w Corsair for my system because I wanted a quiet, reliable PSU with four PCI-E connectors. It will last me a long time, hopefully.
 
MikeHunt79 said:
What PSU brand was it? Hiper PSU's don't achieve their rated wattage for example.

Also, I'd like to see that chart, as that's the first time I've heard of PSU's losing efficiency! :p
Click to expand...


As said it was an Enermax PSU. I carn't find the chart but it was talking about the aging of the capacitors.

Also mentioned here by thermaltake "Electrolytic capacitor aging. When used heavily or over an extended period of time (1+ years) a PSU will slowly lose some of its initial wattage capacity. We recommend you add 20% if you plan to keep your PSU for more than 1 year, or 25-30% for 24/7 usage and 1+ years."

I also though that it was Amperage that was more important than wattage.
 
F2kSel said:
As said it was an Enermax PSU. I carn't find the chart but it was talking about the aging of the capacitors.

Also mentioned here by thermaltake "Electrolytic capacitor aging. When used heavily or over an extended period of time (1+ years) a PSU will slowly lose some of its initial wattage capacity. We recommend you add 20% if you plan to keep your PSU for more than 1 year, or 25-30% for 24/7 usage and 1+ years."

I also though that it was Amperage that was more important than wattage.
Click to expand...
Doh, I really should learn to read! :o Amperage and wattage are the same thing, if your voltage is stable. :)

I'm very surprised a 475W enermax wouldn't power a 8800gtx rig, it's a shame that rig wasn't tested out with one of those wall plug power meters as I find it hard to believe it would pull more than 500W from the wall socket. What PSU was used in the end?

Electrolytic capacitors to do bad over time, that is true, especially if cheaper poor quality capacitors are used. Thermaltake's marketing department have really gone to town tho, it takes much longer than 1 year, it's more like 10 years, before problems occur... But I guess if it's a PSU made by thermaltak then I wouldn't be surprised if they used crappy caps! ;)

I've replaced caps in PA amps before now, they swell up and burst, but this only happens once they're 20 years old, plus the caps spend thier entire life in a hot smoky environment, I'm sure the caps in a PC PSU have a much easier time.
 
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He was only trying the 8800gtx before buying a new PC so that card is now in his new rig at least 650w corsair. I have the same PSU but I only went for a 8800gt and it's been fine, luckily that isn't quite so demanding.

I know at the time we did look at the specs and it was borderline.


I had some bad caps on a motherboard a while back, strangely it kept working for months blowing 1 cap at a time until it died.
 
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F2kSel said:
I had some bad caps on a motherboard a while back, strangely it kept working for months blowing 1 cap at a time until it died.
Click to expand...
Yep often motherboard caps are wired in parallel meaning if one blows the others take up the slack, but it's probably best to RMA it as soon as you can as the electrolyte that comes out of them is pretty horrible stuff!
 
Phil2008 said:
I have a plugin power meter and this is the test I did with my ups pluged in to the power meter. This is whats plugged in the ups and what I had in for the test

My main pc tower (see sig)
2 19" lcd montors (1 on standby)
1 17" lcd monitor (on standby)
Yamaha amplifier
10" sub
2nd pc (on standby)
router
2 external hdd (off)
1 powered usb hub

The test (ups uses about 40watts alone)
223 watts, amp and sub on and playing music from pc
182watts, amp and sub off
263watts, amp and sub off, running furmark
243watts, with amp and sub off, running linx
228watts, with amp and sub off, running orthos
............................................................................................
UPDATED
My 2nd test
PSU plugged into the power meter

105watts, idel in vista
152watts, running orthos
167watts, running linx
169watts, running Intel Burn test v2.2
191watts, running furmark
226watts, running OCCT
270-282watts, running OCCT + Intel Burn test v2.2

So my question is, these insanly high psu's you can buy, is it all a marketing thing, or do we need 750+ watt psus?? Im guessing my 620watt psu will last a few upgrades/builds yet.
Click to expand...

You have to count the PSU's efficiency, so your actual system is only using say 80-85% of that :)
 
MikeHunt79 said:
As a rule of thumb, anything above 450W is not needed unless you're running an SLI setup.
Click to expand...

You be right if you amend that to 450w (37.5A) on the +12v line. :)

Running a PSU at around 20% on idle and 80% sustained top load would be what I'd suggest to aim for, for a good setup. (Naturally some people may want to spec for future upgrades, that's a valid reason for getting a more powerful unit)
 
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