Xbit Does In Depth PSU Requirement Article

[geoffry]

http://xbitlabs.com/articles/c...ay/system-wattage.html

I haven't had time to go through it but they usually do really good stuff.

 

[Beanie46]

Another of these "you don't need more than 500W power supply" articles. And while I agree most "typical" systems don't need massive 1kw power supplies, his notion that 500W units are just fine for high end gaming systems is silly.

Guess he forgot a few things......

First, overclock his cpu and watch wattage requirements climb. And, from what I've seen on various forums, the "typical" user that frequents AT or XS or others tend to overclock like hell.

Next, overclock your gpu and watch your wattage requirements, again, climb. And this doesn't include the small minority that are using SLI/Crossfire with GTX 295's or 4870X2's......and they exist.

Third, running a power supply at 90-95% of rated capacity is just going to shorten your power supply's life rapidly. Heat is the worst enemy of a power supply and longevity.......and running a power supply at its ragged edge is just asking for premature failure.

Fourth, a power supply typically runs most efficiently at 50-60% load, so if you have a system that draws a LOT, like a heavily overclocked i7 920 or 965, and a pair of gpu's in SLI or Crossfire, and your system draws out 500-600W from the power supply, it'd almost make sense to buy an 850W or a little more to give you most efficient supply under heavy draw.

C'est la vie......buy what you want. Personally, I'll overbuy on wattage output of my power supply so I hit right around 50% use of it under load (highest efficiency) and so it'll run cooler and last longer. I'd rather buy once than burn up a power supply and have to spend time RMA'ing it down the road with its subsequent down time.

 

[yh125d]

His notion that 500w units are fine for high end systems is not silly at all. A 500w unit from a quality brand is plenty of power for up to about an oc'd quad and 4850 xfire without going past about 80% usage which is fine for long term use, and at a load level where most quality PSUs will be at least 80% efficiency. Articles like this aren't so much for people buying a 750w PSU for gtx285 sli when they would be fine with a 650, so much as its for people building rigs with a dual core and a mid range card like 4850/gts250 buying a 650w psu to "be safe" because nvidia recommends a minimum 450w, and bad psu calculators recommend 500+

 

[imported_Scoop]

Originally posted by: Beanie46
Another of these "you don't need more than 500W power supply" articles. And while I agree most "typical" systems don't need massive 1kw power supplies, his notion that 500W units are just fine for high end gaming systems is silly.

Guess he forgot a few things......

First, overclock his cpu and watch wattage requirements climb. And, from what I've seen on various forums, the "typical" user that frequents AT or XS or others tend to overclock like hell.

Next, overclock your gpu and watch your wattage requirements, again, climb. And this doesn't include the small minority that are using SLI/Crossfire with GTX 295's or 4870X2's......and they exist.

Third, running a power supply at 90-95% of rated capacity is just going to shorten your power supply's life rapidly. Heat is the worst enemy of a power supply and longevity.......and running a power supply at its ragged edge is just asking for premature failure.

Fourth, a power supply typically runs most efficiently at 50-60% load, so if you have a system that draws a LOT, like a heavily overclocked i7 920 or 965, and a pair of gpu's in SLI or Crossfire, and your system draws out 500-600W from the power supply, it'd almost make sense to buy an 850W or a little more to give you most efficient supply under heavy draw.

C'est la vie......buy what you want. Personally, I'll overbuy on wattage output of my power supply so I hit right around 50% use of it under load (highest efficiency) and so it'll run cooler and last longer. I'd rather buy once than burn up a power supply and have to spend time RMA'ing it down the road with its subsequent down time.

The test left efficiency out of consideration as well so the draw from the wall for the Hi-end gaming PC No 1 was 370.9W. Give a fair 85% to the PSU and the components draw ~315W from the PSU. Now you have room for OC with a 550W PSU.

Don't you want the PSU to run most of the time at the highest efficiency? I guess I'm just talking about myself but my system is mostly idle so it's best to have a PSU where my idle consumption is ~45% of full rated output. If you only use your system to game and shut it down, then I could see going for your approach.

Btw, I don't know what is so 'in depth' about this article, they just measured some systems off the wall. Didn't even try to isolate single components draw. Rather disappointing really.

 

[pcslookout]

Thank finally puts all the people who say you must have a 550 to 600 watt power supply or more to rest.

Great article!

 

[MagickMan]

I always find it comical when people ask for PSU recommendations for a fairly modest gaming system (OC'd quad core w/ 4870 or GTX 260) and they're told, "you need a Corsair 750TX"!

I understand that these companies need to make money, but I can't help but wonder about all the hype. A quality PSU from a reputable company is a must, and none of us want our systems to shut off or stutter while we're gaming or running a benchmark, but someone needs to step forward and comment about the flood of people installing massive power supplies that will never run at 50% of their normal capacity. Before someone comes along and yells, "but they tell people these inflated specs to make up for crap equipment", I'll admit that there's some truth in what they say. However, a good 400-500 watt PSU from Corsair, Seasonic, Antec, or even FSP will handle the job for just about any single GPU rig.

Truth is, it's a testament to the hardware industry that their FUD campaign has become this successful. They've done an excellent job of pulling the wool over people's eyes for a while now.

 

[pcslookout]

Originally posted by: MagickMan
I always find it comical when people ask for PSU recommendations for a fairly modest gaming system (OC'd quad core w/ 4870 or GTX 260) and they're told, "you need a Corsair 750TX"!

I understand that these companies need to make money, but I can't help but wonder about all the hype. A quality PSU from a reputable company is a must, and none of us want our systems to shut off or stutter while we're gaming or running a benchmark, but someone needs to step forward and comment about the flood of people installing massive power supplies that will never run at 50% of their normal capacity. Before someone comes along and yells, "but they tell people these inflated specs to make up for crap equipment", I'll admit that there's some truth in what they say. However, a good 400-500 watt PSU from Corsair, Seasonic, Antec, or even FSP will handle the job for just about any single GPU rig.

Truth is, it's a testament to the hardware industry that their FUD campaign has become this successful. They've done an excellent job of pulling the wool over people's eyes for a while now.

:thumbsup:

 

[F1shF4t]

For setups shown in the article its totaly true, there's no need to get massive psus. On the other hand once you start to massively OC your cpu, have crossfire oced gfx cards, 5-6 hdds, 2 opticals and a ton of fans things might start looking differently. For my rig a 750 watt unit would be enough (in fact it is, used a Tough Power 750 watt before) but I would like it to stay silent and not sound like I have a jet turbine at the back of my case. (After all I want my games and progs to fly not the actual case )

 

[readymix]

i am testing my own rig right now for the purpose of getting a ups. right now with prime95 running 4 cores 100% (q9650@3.0 ghz) and virus scan running for good measure (hdd) has it topping out at 275 watts. that includes 2x7200 rpm raid0, 2x24" lcd, cable modem, router, 2xdvd/rw (idle) and a ati 4670. i have a 550 psu.

 

[yh125d]

Originally posted by: Dark Cupcake
For setups shown in the article its totaly true, there's no need to get massive psus. On the other hand once you start to massively OC your cpu, have crossfire oced gfx cards, 5-6 hdds, 2 opticals and a ton of fans things might start looking differently. For my rig a 750 watt unit would be enough (in fact it is, used a Tough Power 750 watt before) but I would like it to stay silent and not sound like I have a jet turbine at the back of my case. (After all I want my games and progs to fly not the actual case )

You realize that your rig will likely never use more than 30% of that PSU's available grunt? Congratulations, you wasted $200+

 

[Zap]

Originally posted by: MagickMan
Before someone comes along and yells, "but they tell people these inflated specs to make up for crap equipment", I'll admit that there's some truth in what they say.

Of course there is truth to that. For instance I came across this thread today about someone with an Ultra XVS 400W PSU wanting to upgrade video cards. That power supply has 20A total +12v power. Obviously we have some smart here at Anandtech Forums that know they should buy good quality power supplies. However, other people just don't know any better. You can say "has to be good quality with X number of +12v amps" but the average person just needs a simple number to wrap their purchasing decision around.

 

[dangman4ever]

Originally posted by: Beanie46
Another of these "you don't need more than 500W power supply" articles. And while I agree most "typical" systems don't need massive 1kw power supplies, his notion that 500W units are just fine for high end gaming systems is silly.

Guess he forgot a few things......

First, overclock his cpu and watch wattage requirements climb. And, from what I've seen on various forums, the "typical" user that frequents AT or XS or others tend to overclock like hell.

Next, overclock your gpu and watch your wattage requirements, again, climb. And this doesn't include the small minority that are using SLI/Crossfire with GTX 295's or 4870X2's......and they exist.

Third, running a power supply at 90-95% of rated capacity is just going to shorten your power supply's life rapidly. Heat is the worst enemy of a power supply and longevity.......and running a power supply at its ragged edge is just asking for premature failure.

Fourth, a power supply typically runs most efficiently at 50-60% load, so if you have a system that draws a LOT, like a heavily overclocked i7 920 or 965, and a pair of gpu's in SLI or Crossfire, and your system draws out 500-600W from the power supply, it'd almost make sense to buy an 850W or a little more to give you most efficient supply under heavy draw.

C'est la vie......buy what you want. Personally, I'll overbuy on wattage output of my power supply so I hit right around 50% use of it under load (highest efficiency) and so it'll run cooler and last longer. I'd rather buy once than burn up a power supply and have to spend time RMA'ing it down the road with its subsequent down time.

I concur 100% with this statement.

 

[zerocool84]

I bought a PSU that is much more than I need but wanted a great quality PSU and something that can stick with me when I do my next upgrade later this year.

 

[F1shF4t]

Originally posted by: yh125d

Originally posted by: Dark Cupcake
For setups shown in the article its totaly true, there's no need to get massive psus. On the other hand once you start to massively OC your cpu, have crossfire oced gfx cards, 5-6 hdds, 2 opticals and a ton of fans things might start looking differently. For my rig a 750 watt unit would be enough (in fact it is, used a Tough Power 750 watt before) but I would like it to stay silent and not sound like I have a jet turbine at the back of my case. (After all I want my games and progs to fly not the actual case )

You realize that your rig will likely never use more than 30% of that PSU's available grunt? Congratulations, you wasted $200+

I haven't updated my specs but as I said I have a second 4870 card in there.
2 * 4870 use more power than a 295GTX used in the article and I have more hardware, so do an estimate.

The Tough Power 750 watt was turning into a jet turbine and I wanted something quite. Don't see how I wasted anything only costed me ~30% more than a HX620, and'll last me a hell of a lot longer.

 

[Lunyone]

Yes most systems only need a quality 400-500w system, but what about upgrades in 1-2 years?? If you buy something that just meets your requirements now, what about in 1-2 years? Did you factor in 10% capacitor aging into your power requirements?? Did you for see adding another HD/DVD Drive/RAM stick or 2/Upgrade to Quad Core from Duo Core?? These are all things that should be considered. Yes you could spend another $50-75 on a new PSU at time of upgrades, but you could spend $75 now and not upgrade for at least 3-4 years. This is something that should be considered. Yes you could just get by with a 400-500w PSU, but for $10-30 more you can get something that will last you a bit longer. It's up to the individual to decide, but that is my thought on PSU's.