How much does a high end rig pull? Its less than you think...

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MrWizard6600

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http://www.xbitlabs.com/articles/coolers/display/system-wattage_9.html#sect0

I think most of the people who've been hanging out on these boards for a while expected such figures, but since were all too lazy to hook these things up as ammeters ourselves, Xbit labs has done it for us:

Oleg Artamonov of Xbit Labs said:
If you want to have a 50% reserve of wattage, a 750W power supply will be sufficient for a system with a Core i7-920 and a GeForce GTX 295.
Click to expand...
 
MrWizard6600 said:
http://www.xbitlabs.com/articles/coolers/display/system-wattage_9.html#sect0

I think most of the people who've been hanging out on these boards for a while expected such figures, but since were all too lazy to hook these things up as ammeters ourselves, Xbit labs has done it for us:
Click to expand...

that is a fairly optimistic configuration they used as well. no overclock on the i7 920 or video, no sound card or other expansion card, only 3gb ram, single hd... very few people would setup their own i7 gtx295 system in such a limited manner.
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But HDDs, sound cards, and RAM are low energy users. HDDs use maybe 15W at most? And sound cards/RAM even less...
 
haffey said:
But HDDs, sound cards, and RAM are low energy users. HDDs use maybe 15W at most? And sound cards/RAM even less...
Click to expand...

all that little stuff adds up. few fans here, more ram, couple more hard drives and you can make a fairly big increase in power usage .

the way that article is written, sounds like most people wold be fine buying a 450w psu for a gtx295 + i7 system.
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I wonder what mine is using now? I haven't installed Powerchute with my Vista install.
Q6600 OC to 3Ghz, 2GBx4 DDR2 1066, GTX285, 9 Hard Drives, 2x 80mm fans, 2x 120mm fans, DVD-RW, and an Audigy 2 ZS Platinum.
 
Zepher said:
I wonder what mine is using now? I haven't installed Powerchute with my Vista install.
Q6600 OC to 3Ghz, 2GBx4 DDR2 1066, GTX285, 9 Hard Drives, 2x 80mm fans, 2x 120mm fans, DVD-RW, and an Audigy 2 ZS Platinum.
Click to expand...
Probably no more than 450W under full load.
 
I do know that a 350 Watt PSU would be enough for the X2 3800+ server I put together last year. Darn thing rarely gets past 100 Watt according to the APC UPS it's connected to. It's even got an 8500GT in it :p
 
True that on total watts you may not exceed 450, but will you exceed the amps on a particular rail is the question. If you have a high end video card that sucks more 12 volt amps than you have available then the total watts will not matter, you will come up short.
 
We've done tons of power measurements on many system configurations. Even the Skulltrail didn't pull as much power as you might expect it would have. With that said, I've actually had a computer pull 1,100 watts while gaming. That was my Skulltrail with two overclocked QX9775's, two 4870 X2's in CrossfireX, and 4 150GB Raptors in RAID0+1. When the 4870 X2's didn't work out quite right I went to 3 Geforce GTX 280 OC's in 3-Way SLI and the power draw fell quite a bit. Down to about 900 watts as I recall. Now my system uses less than that with the Core i7 920 @ 4.2GHz and the same video card setup using a pair of Western Digital Velociraptors. I've got a couple of Intel X25-M 80GB SSD's in RAID0 now but I haven't measured the power usage. I'd imagine it would be similar to the Velociraptor configuration.
 
simply put i would rather have more then what i need............then less what i need.
 
I have been saying this for years... you don't need grossly oversized expensive power supplies. A good quality 500 watt PSU will suffice for 90% of those who think they need a 1k PSU.

My own PC pulls a measly 310 watts at full load via my PSU's built in power meter. (E8400, 8800 GTS, 4GB, 3 HD's, etc)
 
But there is something to be said about buying twice the amount you will max out on full load during gaming, etc., since power supplies tend to run at their most efficient at 50-60% of rated capacity.

So, if you're pulling like 375W at full load, running a 450W power supply is running that power supply on its downward slope of efficiency and missing its peak efficiency.

Also, there's the fact that running a power supply close to its max rated capacity produces more heat within that power supply, effectively shortening its life expectancy.

And it's not hard assembling a system to draw 400W.....a simple system with a Q9550 OC'd a little to 3.8GHz, a single 4870 1GB video card OC'd very mildly, 8GB RAM, two 1GB hard drives, a DDC2 pump for watercooling can and does approach 400W of draw under gaming and broaches 400W but a little under OCCT's psu test.

So while it's true you can get buy with a smallish power supply for most users' setups, to use XBit Lab's test as a blanket statement for everyone's needs is doing a great disservice to the OC'ing community. As we all know, as you increase the overclock of any particular cpu, the power use of that cpu increases quite a bit, as does with OC'ing a gpu.

Personally, I'd much rather spend a few more dollars and overbuy on wattage in my power supply and let it run at 50% of rated capacity while loading my system instead of having it run strung out close to its max capacity when loading my computer during hours of gaming.
 
C'DaleRider points are on the nail.

I will add that PSUs derate (reduce) their efficiency with temperature and age.
The harder you push a PSU the hotter it gets and the faster it will age, the more it has aged, the less power it can produce.
This then means that you are running even nearer its max output, causing it to wear even faster and run even hotter...
The first signs of this getting serious may be lack of stability but the power supply can simply die without any warning.
This can result in damage to anything connected to the PSU.

Overclocking can add a substantial extra burden to the PSU if you raise voltages as well.
Power is proportional to the square of the voltage so maintaining the same clocks and going from say 1.1V to 1.3V on the CPU will use approx 40% more power!
Changing the speed to higher uses a bit more power but its not in the same ballpark as changing the voltage.

Same for gfx cards, motherboard chipsets, memory...

If you are going to push a PSU hard, keep it as cool as possible.
Better still, replace it with something that will last you more than a year or 2, taking into account that they do wear (max output current reduces).
 
For what its worth, I couldn't agree more. I don't know why more folks don't spend more coin on the things that could last them 5+ years.....like a good psu (pcp&c tc1200) which sports a 7 year warranty and prolly won't be outgrown by upgrades....or a good case which is always a good investment imho.
 
I'm hoping my Corsair 850HX will last a while... I doubt I'll ever out-grow it... I'm just worried more about connections then anything, but I have a feeling Corsair will be able to make cables/adapters for the modular side to upgrade you if need-be...

7-yr warranty, and plenty of power... and was reasonable at $160... I paid close to that for my Ultra X3 600watt... but that one was pretty nice too...
 
That's just about in line with what I would expect. Overclock the 920 and throw in another GPU and you're going to draw a lot more power, though. Especially those GTX cards... they draw a LOT of power compared to other cards.

I know my 550vx is just barely enough for my set up, detailed below (+ 2 HDDs, fan controller, BD drive, many fans). I don't think I could switch my 8800GT for a GTX 260.. but I wouldn't need to anyway as I can already run all my games at maxed settings.

Contemplating changing to an HX850 though so I can get better efficiency... and so I don't hear my PSU whining while encoding.
 
You're probably looking at something around or just above 300W with that rig in your signature. (CPU wattage could probably vary depending on how much voltage you're feeding it).

Still, with that, the VX550 still has headroom. The fan is probably spinning up though and causing the noise, CWTs aren't too quiet.
 
Riddle me this....why do people buy and run smaller psu's, with virtually no expandability and very close to the systems/psu's limits, just to save 50$-100$? When a psu running at its limits has a shortened lifespan and could take alot with it when it goes, I just don't get why others do that.
 
JoeBob said:
Still, with that, the VX550 still has headroom. The fan is probably spinning up though and causing the noise, CWTs aren't too quiet.
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Corsair sets their own fan profiles on all their PSUs. Even the VX550 is very quiet, although at higher loads the fan will be audible. I wouldn't expect any significant noise levels until at least 400-450W of load though.
Romdominance said:
Riddle me this....why do people buy and run smaller psu's, with virtually no expandability and very close to the systems/psu's limits, just to save 50$-100$? When a psu running at its limits has a shortened lifespan and could take alot with it when it goes, I just don't get why others do that.
Click to expand...
Well, there are a few reasons. First of all, not all people are informed enough to know what their needs are, so they make their decisions out of ignorance. Some people don't plan on upgrading to components with higher power requirements, so they don't need their PSU to have extra capacity for future increased power demands. Some people just plan on upgrading their PSU along with the rest of their components in the future. And some people just don't plan on upgrading their PCs altogether. It isn't practical or even beneficial to everyone to purchase a PSU with extra capacity. Sometimes it's just pointless.
 
guess you just explained how dell and gateway still do a decent business in desktops....
sorry, its just hard for me to get my head around people that care enough to build their own rig, not caring about oc'n, growth, longevity and the need to go faster...;)
 
Zero82z said:
Corsair sets their own fan profiles on all their PSUs. Even the VX550 is very quiet, although at higher loads the fan will be audible. I wouldn't expect any significant noise levels until at least 400-450W of load though..
Click to expand...

Well, you're probably right, come to think about it, all the Corsair PSUs I've been through have been Seasonic made. The noise he's talking about might be fan generated, or something else.
 
Romdominance said:
sorry, its just hard for me to get my head around people that care enough to build their own rig, not caring about oc'n, growth, longevity and the need to go faster...;)
Click to expand...
Durability of computer is very relative, normally it is very long and only reason why are operational computer components replaced is because we want to make them more faster according to game and software development, if this "trend" wouldn't exist we are still running on 10-15 year old computers. In basic principle hardware is still the same and functionality of nowadays computers is same as those first designed. The durability of computer is mostly negatively affected by high load and long up-time, those who playing games all the time or using some high-demanding programs, such as creation tools or formula processing software and rebooting/turning off computer very rarely cause computer to high stress and after few years the computer's PSU or mainboard can stop working for unknown reason or computer become unstable. Mostly capacitor explosions or chip damage even it was not overheated or overpowered.
The other durability decreasing is caused by heat that affects all components if they are not well cooled. The office work computers or home one which are displaying websites have predict to have longer life-span due to lower load than gaming or profi rigs. I'm trying to reduce this by turning computer off everytime when it's not in use so it can rest. This is same for all computers, playing older games on new computer also causing it under high load, the games are just steady because is fast enough. Same is for LCD monitor stress - long up-time cause lowering brightness of backlight, CRT monitor stress - using high brightness/contrast levels - decreasing sharpness of the screen and overall brightness goes down. PSU stress - running PSUs on the top of their limits can make them unstable or stop working.
 
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