This is the exact reason why I had to upgrade my PSU. Had the wattage, but not the amps. Not all PSUs of the same wattage have the same amperage.

Unfortunately what you're describing is advertising B$.
There is no standard for the rating of PSUs. An honestly rated PSU (say 500W) is 500W with the load on the 5V, 12V & 3.3v rails. Due to the lack of standards, there is no requirement for the ratio of power supplied by each rail.
eg one 500W PSU might be supplying 60A on the 12V rail, and 40A on the 5V rail. Another might supply 40A on the 12V & 60A on the 5V rail.

The worst ones are the ones that give their power rating, but for the total maximum of all the rails combined- which is a load of bollocks as no PSU is rated to supply full load on all rails simutaneously.

If one buys a cheaply made psu, One gets what one pays for. As always Caveat Emptor...

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The T1 Trust, PRR T1 Class 4-4-4-4 #5550, 1 of America's First HST's

I don't know if it is still relevant these days, but around five years ago, PSU-buying guides said to pay close attention to the 5v amperage, because a lot of cheaper units will have an astronomical 5v output to bring the overall capacity up, and not do much for 12v which is the one you need the most of.

That's not saying 5v isn't important, but it is something to look at and take into consideration.

Also, as has been mentioned at least once.. weight is important. If it is really heavy, then it should be more suited to providing a stable output when sudden loads are put on it.

I remember a few years ago I got an EPS (24+8..was before desktop boards had 24-pin main) unit, and it was I think a 600, and it weighed about as much as a DVD burner. With just two Athlon MPs, a single stick of DDR-400, and a single HDD, it smoked in less than 3 days. I've got some 300w old school units that weigh like 5 pounds and I've used them in rigs, and hot-wired them for electrolysis experiments and so forth. Weight=reliable.

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Linux laptop:
record uptime: 1511d 20h 19m (ended due to the power brick giving-up)

I don't know if it is still relevant these days, but around five years ago, PSU-buying guides said to pay close attention to the 5v amperage, because a lot of cheaper units will have an astronomical 5v output to bring the overall capacity up, and not do much for 12v which is the one you need the most of.

That's not saying 5v isn't important, but it is something to look at and take into consideration......

Up until about 10yrs ago most PC's really only loaded the 3.3v and 5v rails so the 12v rail didn't need to be hefty at all.

Cheers.

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I don't know if it is still relevant these days, but around five years ago, PSU-buying guides said to pay close attention to the 5v amperage, because a lot of cheaper units will have an astronomical 5v output to bring the overall capacity up, and not do much for 12v which is the one you need the most of.

That's not saying 5v isn't important, but it is something to look at and take into consideration......

Up until about 10yrs ago most PC's really only loaded the 3.3v and 5v rails so the 12v rail didn't need to be hefty at all.

Cheers.

Yeah how times and technology has changed, 12v is really important today and 5v will one day disappear from psus.

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The T1 Trust, PRR T1 Class 4-4-4-4 #5550, 1 of America's First HST's

I don't know if it is still relevant these days, but around five years ago, PSU-buying guides said to pay close attention to the 5v amperage, because a lot of cheaper units will have an astronomical 5v output to bring the overall capacity up, and not do much for 12v which is the one you need the most of.

That's not saying 5v isn't important, but it is something to look at and take into consideration......

Up until about 10yrs ago most PC's really only loaded the 3.3v and 5v rails so the 12v rail didn't need to be hefty at all.

Cheers.

Yeah how times and technology has changed, 12v is really important today and 5v will one day disappear from psus.

I doubt that the 5v rail will disappear any time soon as HDD's, USB ports and other hardware require that rail, if any rail disappears soon it'll be the 3.3v rail as motherboards will just breakdown the 5v rail to suit lower voltage requirements, but I won't hold my breath waiting for that to happen either. ;)

Cheers.

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I don't know if it is still relevant these days, but around five years ago, PSU-buying guides said to pay close attention to the 5v amperage, because a lot of cheaper units will have an astronomical 5v output to bring the overall capacity up, and not do much for 12v which is the one you need the most of.

That's not saying 5v isn't important, but it is something to look at and take into consideration......

Up until about 10yrs ago most PC's really only loaded the 3.3v and 5v rails so the 12v rail didn't need to be hefty at all.

Cheers.

Yeah how times and technology has changed, 12v is really important today and 5v will one day disappear from psus.

I doubt that the 5v rail will disappear any time soon as HDD's, USB ports and other hardware require that rail, if any rail disappears soon it'll be the 3.3v rail as motherboards will just breakdown the 5v rail to suit lower voltage requirements, but I won't hold my breath waiting for that to happen either. ;)

Cheers.

Here's something that if the Rumors are true, Will spank Yer rails but good, The GTX590, The story can be forund Here @ Nordic Hardware. Can You say 244-488w consumption all on one card? If this thing is made people may need not only a psu upgrade, but a case upgrade as well.

The GTX590, Note the two 8pin power plugs on the upper right and the 3 DVI ports on the left.

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The T1 Trust, PRR T1 Class 4-4-4-4 #5550, 1 of America's First HST's

I am a big fan of Corsair supplies - I just ordered a new 750 (CMPSU-750HX) for my next build.
Don't worry to much about it - 7yr warranty and 80 PLUS SILVER Certified!
Newegg has it on sale for 129.00 with free shipping. Use this promo code: EMCKHJJ36 (expires in 2 days) and this turns into a great deal (steal) at $114.00 usd.
Here is the link to the supply I am talking about:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139010&nm_mc=EMC-IGNEFL021111&cm_mmc=EMC-IGNEFL021111-_-EMC-021111-Index-_-PowerSupplies-_-17139010-L06C

I have never had a Corsair supply burn up yet.

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I am a big fan of Corsair supplies - I just ordered a new 750 (CMPSU-750HX) for my next build.
Don't worry to much about it - 7yr warranty and 80 PLUS SILVER Certified!
Newegg has it on sale for 129.00 with free shipping. Use this promo code: EMCKHJJ36 (expires in 2 days) and this turns into a great deal (steal) at $114.00 usd.
Here is the link to the supply I am talking about:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139010&nm_mc=EMC-IGNEFL021111&cm_mmc=EMC-IGNEFL021111-_-EMC-021111-Index-_-PowerSupplies-_-17139010-L06C

I have never had a Corsair supply burn up yet.

That should be a good psu, I have the 850TX version.

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The T1 Trust, PRR T1 Class 4-4-4-4 #5550, 1 of America's First HST's

I am a big fan of Corsair supplies - I just ordered a new 750 (CMPSU-750HX) for my next build.
Don't worry to much about it - 7yr warranty and 80 PLUS SILVER Certified!
Newegg has it on sale for 129.00 with free shipping. Use this promo code: EMCKHJJ36 (expires in 2 days) and this turns into a great deal (steal) at $114.00 usd.
Here is the link to the supply I am talking about:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139010&nm_mc=EMC-IGNEFL021111&cm_mmc=EMC-IGNEFL021111-_-EMC-021111-Index-_-PowerSupplies-_-17139010-L06C

I have never had a Corsair supply burn up yet.

That's the model i'm running on my E8500/GTX460/HD5770, was running a HX620 until about a month ago,
the HX620 is now running the XP3200/HD4650, need to go lower still there, 200 to 250W PSU is really all that's needed atm, as it's only pulling 143W,

Claggy

don't get the TX corsair power supplies for crunching, the HX Corsair power supplies are more efficient and if your crunching 24x7 it will save you money in the long run.

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I avoid modular at all costs. The last thing I need to deal with years down the road is power issues because of failing connection points and/or possible oxidation.

Unfortunate too, since modular seems all the rage these days.

agree.... whats the point of having a modular 24 pin connector, 4/8 pin 12v connector? if the ps is above 600 watts it should at least have one set of non modular pci-e connector.

if a ps has 8 pcie cables, i can see having half modular. i do like modular drive cables, because i can just use the ones i want.

i do wish they would standardize modular cables so i wouldn't have to keep track of which go to the correct ps. god forbid you use the wrong one!!!

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Here's something that if the Rumors are true, Will spank Yer rails but good, The GTX590, The story can be forund Here @ Nordic Hardware. Can You say 244-488w consumption all on one card? If this thing is made people may need not only a psu upgrade, but a case upgrade as well.

The GTX590, Note the two 8pin power plugs on the upper right and the 3 DVI ports on the left.

nice, i do hope someone has a cooling solution which will not exhaust into the case as this will just cause EVERYTHING to over heat.

my three gtx295's, dual pcb design, are in a danger den water box so the motherboard sits horizontal (flat) and the cards are air cooled and DO dump some heat into the case; therefor, i had to cut and mount a 120mm exhaust fan above the back of the cards to pull the heat out. i also have a paper chimney to direct the heat up and away.

by the way the system is off as it has no work:(

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don't get the TX corsair power supplies for crunching, the HX Corsair power supplies are more efficient and if your crunching 24x7 it will save you money in the long run.

Actually looking at my PSU, it is a CMPSU-750TX, and not a HX,
I've had it sat around for a year now, occasionally powering the XP3200/HD4650 to perform Hybrid Astropulse tests for Raistmer,
looking at Corsair's site, i see what you mean about efficiency, HX being preferable the the TX,
but being on 240Vac, the drop off in efficiency isn't as bad as being on 115Vac,
i did measure the power draw before and after, and they were practically the same at around 400W,
so i didn't loose any effiency, or gain any eithier, so next time i will go for a HX or better,

Claggy

I avoid modular at all costs. The last thing I need to deal with years down the road is power issues because of failing connection points and/or possible oxidation.

Unfortunate too, since modular seems all the rage these days.

agree.... whats the point of having a modular 24 pin connector, 4/8 pin 12v connector? if the ps is above 600 watts it should at least have one set of non modular pci-e connector.

if a ps has 8 pcie cables, i can see having half modular. i do like modular drive cables, because i can just use the ones i want.

i do wish they would standardize modular cables so i wouldn't have to keep track of which go to the correct ps. god forbid you use the wrong one!!!

I generally like the psus that have the main cables permanently attached to the psu, The others for the video cards and the peripherals can be modular, Although for My big build, That went out the window, As I didn't see a lot of choice above 1250w, Not and be able to support 4 GTX295 cards, So I got the ST1500 and It's as Modular as one can get.

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The T1 Trust, PRR T1 Class 4-4-4-4 #5550, 1 of America's First HST's

Don't rely on all advice given heretofore in this thread, some is pure BS.

First off, buying big is never bad advice. In fact, I recall some PSU makes posting efficiency charts that showed their product doing their most power friendly work at some 70-80 percent of full load. Voltage stability was optimized in that range as well. So DON'T buy a PSU that will be loaded to the hilt.
Second...I don't think anybody mentioned the advantage of a PSU with a single 12v rail. They used to be rare, maybe they are more common now. If you don't know the difference, some PSUs divide the 12v supply into several 'rails'.....
Which means that a certain connector chain can only supply a portion of the total PSU output. You can overload that particular connector chain without drawing the maximum output of the PSU. A single 12v rail means you can get the total output of the PSU from any connector combination you happen to use.

Third..Cheap is not always best.....
I know......most expensive is not always either.
The kittyman's pick o' the litter? Always.......PC Power and Cooling Silencer series. Period. The Frozen 920 draws about 840 watts from a 910w Silencer.....and it barely makes a giggle. Not much heat from the cooling fan, which means it is very efficient at converting AC to DC.

You want the best......that is it. If not, at least don't shortchange yourself on the wattage. If the manufacturer you are considering does provide the graphs I spoke of earlier, peruse them.

My guess is that most PSUs are best with about a 70 to 80 percent load. It will optimize their voltage regulation and prolong their life.

Geezus, DON'T buy 'just enough'.....I got enough bytes under my belt to say so.

Would the kittyman steer 'ya wrong?

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"Freedom is just Chaos, with better lighting." Alan Dean Foster

PC&C is what I've used for years.Now, the MKII series is produced on the same sirfa platform that OCZ Z-Series is produced on instead of the good S12D platform from Seasonic, well because they own them now, which also means they are produced in China now. The transformers in them have been swapped over to the Rong Chyuan that the enermax supplies use. For all intensive purposes the new PC&C's are just a rebadged OCZ-Z series part. Rather thats good or bad I'm not sure as I've never used OCZ products. Think my next supply will probably be a Corsair(CWT platform) ,Seasonic or PC&C. PC&C I'm still a bit leery about even though supposedly the design changes they have made are supposedly for the better, it just doesn't sound great to me, and they are charging for the name instead of the quality now.

As far as at what power level to buy, with most of them being rated 80+ that means they hit their top efficiencies at 50-75% utilization. Meaning you want, whatever you system need, to be within that range. If your system needs 600 watts, you would want a supply that is 850-950 watts. At least that's my thinking and it's always seemed to work out ok.

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Traveling through space at ~67,000mph!

Don't rely on all advice given heretofore in this thread, some is pure BS.

First off, buying big is never bad advice. In fact, I recall some PSU makes posting efficiency charts that showed their product doing their most power friendly work at some 70-80 percent of full load. Voltage stability was optimized in that range as well. So DON'T buy a PSU that will be loaded to the hilt.

My guess is that most PSUs are best with about a 70 to 80 percent load. It will optimize their voltage regulation and prolong their life.

Geezus, DON'T buy 'just enough'.....I got enough bytes under my belt to say so.

[Edited your post to address the points I wanted to]

I think you just stated what I stated, which is "buy what you need", but if you're saying it's OK to buy a 1500W PSU when you only use 425W, then I can't agree.

Of course it's not wise to buy at full tilt, but don't overdo it either. That's the point.

Otherwise I agree with everything you just said - including PC P&C being the best.

Don't rely on all advice given heretofore in this thread, some is pure BS.

First off, buying big is never bad advice. In fact, I recall some PSU makes posting efficiency charts that showed their product doing their most power friendly work at some 70-80 percent of full load. Voltage stability was optimized in that range as well. So DON'T buy a PSU that will be loaded to the hilt.

My guess is that most PSUs are best with about a 70 to 80 percent load. It will optimize their voltage regulation and prolong their life.

Geezus, DON'T buy 'just enough'.....I got enough bytes under my belt to say so.

[Edited your post to address the points I wanted to]

I think you just stated what I stated, which is "buy what you need", but if you're saying it's OK to buy a 1500W PSU when you only use 425W, then I can't agree.

Of course it's not wise to buy at full tilt, but don't overdo it either. That's the point.

Otherwise I agree with everything you just said - including PC P&C being the best.

LOL....I didn't state that that much overkill was the point.

I certainly would not tell somebody to buy 1.5 Kwatts when their system was targeted at 600. I might suggest 800w or so.

Whatever, YMMV........just take my advice in stride, and don't underbuy.
To err is human, to err on the wrong side is being misadvised.

Meow.

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"Freedom is just Chaos, with better lighting." Alan Dean Foster

I don't know if it is still relevant these days, but around five years ago, PSU-buying guides said to pay close attention to the 5v amperage, because a lot of cheaper units will have an astronomical 5v output to bring the overall capacity up, and not do much for 12v which is the one you need the most of.

That's not saying 5v isn't important, but it is something to look at and take into consideration......

Up until about 10yrs ago most PC's really only loaded the 3.3v and 5v rails so the 12v rail didn't need to be hefty at all.

Cheers.

Yeah how times and technology has changed, 12v is really important today and 5v will one day disappear from psus.

I doubt that the 5v rail will disappear any time soon as HDD's, USB ports and other hardware require that rail, if any rail disappears soon it'll be the 3.3v rail as motherboards will just breakdown the 5v rail to suit lower voltage requirements, but I won't hold my breath waiting for that to happen either. ;)

Cheers.

Here's something that if the Rumors are true, Will spank Yer rails but good, The GTX590, The story can be forund Here @ Nordic Hardware. Can You say 244-488w consumption all on one card? If this thing is made people may need not only a psu upgrade, but a case upgrade as well.

The GTX590, Note the two 8pin power plugs on the upper right and the 3 DVI ports on the left.

This is what EVGA was showing at CES 2011
http://www.geeks3d.com/20110108/ces-2011-evga-gtx-590-gemini-dual-gpu-card/

I don't know if it is still relevant these days, but around five years ago, PSU-buying guides said to pay close attention to the 5v amperage, because a lot of cheaper units will have an astronomical 5v output to bring the overall capacity up, and not do much for 12v which is the one you need the most of.

That's not saying 5v isn't important, but it is something to look at and take into consideration......

Up until about 10yrs ago most PC's really only loaded the 3.3v and 5v rails so the 12v rail didn't need to be hefty at all.

Cheers.

Yeah how times and technology has changed, 12v is really important today and 5v will one day disappear from psus.

I doubt that the 5v rail will disappear any time soon as HDD's, USB ports and other hardware require that rail, if any rail disappears soon it'll be the 3.3v rail as motherboards will just breakdown the 5v rail to suit lower voltage requirements, but I won't hold my breath waiting for that to happen either. ;)

Cheers.

Here's something that if the Rumors are true, Will spank Yer rails but good, The GTX590, The story can be forund Here @ Nordic Hardware. Can You say 244-488w consumption all on one card? If this thing is made people may need not only a psu upgrade, but a case upgrade as well.

The GTX590, Note the two 8pin power plugs on the upper right and the 3 DVI ports on the left.

This is what EVGA was showing at CES 2011
http://www.geeks3d.com/20110108/ces-2011-evga-gtx-590-gemini-dual-gpu-card/

Truly awesome card!

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The T1 Trust, PRR T1 Class 4-4-4-4 #5550, 1 of America's First HST's