Powersupply Requirements are Overstated

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Spare-Flair

Supreme [H]ardness
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I'm really getting a little perturbed at how many threads fill up with people telling other people that their PSUs aren't good enough for certain cards. Whenever somebody posts about a problem, the first responses in most threads are: "is your PSU enough?" I think it needs to be clarified that the stated requirements for videocards are worse-case scenario failsafe requirements, they are recommended requirements for maximally taxing systems, they are not mininum requirements.

It's NEVER a bad idea to have a quality PSU. In fact, that is always a good thing but I just wanted to illustrate that it's not always neccessary and people don't need to be panicking or trying to convince others that they don't measure up. Even the teenager at Best Buy told me: "you'd better have a 600 watt powersupply!" when I bought one of my 8800GTs. I replied that I had a 250watt PSU and I was already running an 8800GT fine and he had a blank look on his face.

The 8800GT in many reviews show that the total system (that's everything in the test rig together) draw was only 220-240watts. G92s are very robust and low in power requiments. The GTS requires 24A on the +12V and the 8800GT about 22A on the +12V but my Shuttle PSU only provides 16A and everything is running fine. It never crashes, never fails to boot, etc.

Anyway, just wanted to point out that the first place you look or the first suggestion you offer to people posting about issues shouldn't neccessarily always be the PSU and you don't need to be scared into buying a new one unless you truly have an unreliable and el-cheapo brand or plan on running a lot of hardware in your system (multiple drives, multiple fans).
 
Thanks. To be honest, I was scared that if I upgraded to a 9600GT, it would not run well on my antec neopower 480.
 
Just to chime in here, I had a PCP&C 510W powering an AMD FX60, 2x1gb ram, 5! HDDs, Soundblaster X-Fi Platinum, DVD Burner, 2 80mm and 2 120mm, and TWO 7950gx2s and the thing didn't hiccup once. I know what you're saying.
 
Funny how everyone thinks they need a huge PSU for Video Cards, isnt it? Im guessing alot of its now marketing, if youve noticed some VGA vendors are getting into the PSU game. MAYBE eventualy theyll remove the bloated power Requirements and just say "Works Best With Any BFG PSU".

Im running a C2D set-up with 4GB RAM, 250GB HD, Water Pump, and ATI 3850 512m off of a 200w PSU. Ive still got some slack, according to my P3 voltage reader, so Im going to try for a 8800GT. Might be pushing it but not by much. Just goes to show an overpriced 700w PSU is certainly not needed.

Those interested in power should check out SPCR. They have a ton of information on how to get the most out of your power supply and whats best for your system.
 
The idea behind that is that many of the lower wattage PSUs use low quality capacitors. This, and because if you run a PSU 100% of its maximum capacity all the time, it will take a huge crap on you and possibly destroy one of your other expensive components.
 
I guess thats a good reason for those that dont know anything about power supplies. Im guessing the people that use brands like PC&C, Seasonic, Pico, ect. are a very small percentage of users. And the bloated specs can be justified if its a horrible inefficent PSU.

This, and because if you run a PSU 100% of its maximum capacity all the time, it will take a huge crap on you and possibly destroy one of your other expensive components.
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This shouldnt be to much of an issue in todays day and age. CPUs are drawing less power, chipsets are drawing less power, hard drives are drawing less power, ddr2 is drawing less power, and GPUs are drawing less power while PSUs continue to get more efficent. Its not to hard to get a good, modern system to 30w or below for desktop use/internet surfing. Thats far below even a 200w PSU so no worries on pushing the PSU to its limit constantly. But then again that would require some knowledge on the consumers part. So I think that cancels out the vast majority of people and again justifies the bloated rating.
 
Been my personal experience that quality trumps total watts. I knew I went overboard with getting 620W PSU but I was happy with the deal I got on it. I am getting my 8800GT in today and thanks to "Kill A Watt" I am anxious to see my system's power draw at the outlet.
 
I'm well pleased that my 400W non-branded PSU, with only 18A rating on the +12V rail (although it's not one of those lightweight PSUs that come with the casings) can drive my rig with no problems. ;)

I'm running an 8800GTS (G92), with 3 Sata HDDs, an old Prescott P4 3.2 CPU, an Audigy 2 ZS soundcard (with front bay), a DVD burner, and 3 sticks of DDR RAM (2Gb combined).
 
For a while the main concern has been amps available on 12v rail(s). I just add up the system power requirements manually with a small buffer. Right now the biggest PSU I have is 430W (TruePower Trio) and that's more than enough for the overclocked 8800GT (plus overclocked CPU) I'm getting in this week. The generic requirements on the box are a rough guide, and will of course vary from system to system: E6600 vs QX9650, total number of drives, etc.

In my SFF systems with 200W PSUs and only 10A on 12V I have run Core 2 class (E4300, E2200) and X2 BE-2300 CPUs with lower end video cards (x1650 Pro and 8400GS) without problems under full load.
 
I ran a overclocked 2900XT WITH the system in my sig. Never had a single issue. So yeah, PSU requirements tend to be overblown (assuming you have a quality PSU).
 
Yes, the minimum requirements are often overstated.

But you still want to get a powersupply about 2x what the system actually draws.

Reason being, that powersupplies are usually the most efficient at about 50% load. If you are using a 300 watt powersupply to run a 250 watt computer, you are using more electricity than if you are using a 500 watt powersupply to run the same 250 watt computer. That said, you don't want to get a 1000 watt powersupply either, as the effieciency also degrades as you go to low of a load.

The system with the proper wattage powersupply will also be a degree or two cooler. You also want to leave a little bit of room for power company problems or weak interior wiring (like if you lights dim every time you turn on your laser printer or microwave) A little bit of room for upgrades helps too.

I try to get my systems right around 65% at load, which usually means a 430, 450 or 500 watt powersupply. And like bread, you want one made in 2006 or later as they tend to overall be more efficient (There also were some great quality powersupplies made in the late 1980's, but thats too far away now)
 
This comes from video card manufacturers overstating the requirements because they know most PSUs on the market are shit and can't out put near what they are rated for. Rather than telling you to buy a quality 500-600watt PSU for virtually every high end configuration, they say 800watt plus hoping it gives enough of a safety net to eliminate most power supply problems.
 
Spare-Flair said:
I'm really getting a little perturbed at how many threads fill up with people telling other people that their PSUs aren't good enough for certain cards. Whenever somebody posts about a problem, the first responses in most threads are: "is your PSU enough?" I think it needs to be clarified that the stated requirements for videocards are worse-case scenario failsafe requirements, they are recommended requirements for maximally taxing systems, they are not mininum requirements.

It's NEVER a bad idea to have a quality PSU. In fact, that is always a good thing but I just wanted to illustrate that it's not always neccessary and people don't need to be panicking or trying to convince others that they don't measure up. Even the teenager at Best Buy told me: "you'd better have a 600 watt powersupply!" when I bought one of my 8800GTs. I replied that I had a 250watt PSU and I was already running an 8800GT fine and he had a blank look on his face.

The 8800GT in many reviews show that the total system (that's everything in the test rig together) draw was only 220-240watts. G92s are very robust and low in power requiments. The GTS requires 24A on the +12V and the 8800GT about 22A on the +12V but my Shuttle PSU only provides 16A and everything is running fine. It never crashes, never fails to boot, etc.

Anyway, just wanted to point out that the first place you look or the first suggestion you offer to people posting about issues shouldn't neccessarily always be the PSU and you don't need to be scared into buying a new one unless you truly have an unreliable and el-cheapo brand or plan on running a lot of hardware in your system (multiple drives, multiple fans).
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Good luck to you.
Right now you are running your 250W PSU on the red line every time you use a 3D application. The Shuttle PSUs are excellent, but dont curse it when it blows.
Most PSUs are "rated" to put out about 80% of their capacity at 50% load, the higher the load, the less the efficiency.
I dont see an issue with the recommendations from ATI or Nvidia....if your PSU goes down in flames, many times it will take out the entire computer along with it.
Just because you are lucky, doesnt mean you can decry the experience of the company that builds and tests the GPU.
 
2 8800 GTS (G92)s + E8400 (stock) + 780i + 1 HDD + 1 DVD + 4 case fans = Idles at like 220W (measured between the PSU and the wall. Full load is like 280 or 380 I can't remember which off the top of my head. Long story short my quality 620HX is a joke for the system.
 
vengence said:
2 8800 GTS (G92)s + E8400 (stock) + 780i + 1 HDD + 1 DVD + 4 case fans = Idles at like 220W (measured between the PSU and the wall. Full load is like 280 or 380 I can't remember which off the top of my head. Long story short my quality 620HX is a joke for the system.
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You can see the power requirements by two different high end rigs. As you can see neither one of them would need a 800watt+ PSU in their test configurations.

http://www.hardocp.com/article.html?art=MTQ1OCw3LCxoY29uc29sZQ==

Intel actually recommends a 1kw PSU minimum for that setup and 1200watts for a dual GPU configuration. They also recommend 1600watts for four GPUs. Obviously the actual requirements aren't nearly that bad.
 
Precisely.
My computer has Q6600+680i+8800 GTX x 3+ 4GB RAM+ 2 HDD+watercooling and most likely doesnt even make my 1000W PSU break a sweat,however the nvidia recommendation for my set was 1200W if I recall; but on the other hand I wouldnt want to try it with 600W.

Again I'm not knocking the Shuttle PSU, I have a Shuttle that runs an AMD 3500+, 2 GB RAM, 3HDD, and a 6800 GT just fine.

My biggest concern is actually house wiring in the future. As we go higher and higher in wattage and current draw from PSUs, when are we going to need dedicated lines in our houses for this stuff. I mean 1000W PSUs pull about 13 Amps already by themselves. My computer room circuit has a 20 AMP breaker. Soon I will have to sit in the dark with no heat.
 
magoo said:
Precisely.
My computer has Q6600+680i+8800 GTX x 3+ 4GB RAM+ 2 HDD+watercooling and most likely doesnt even make my 1000W PSU break a sweat,however the nvidia recommendation for my set was 1200W if I recall; but on the other hand I wouldnt want to try it with 600W.

Again I'm not knocking the Shuttle PSU, I have a Shuttle that runs an AMD 3500+, 2 GB RAM, 3HDD, and a 6800 GT just fine.

My biggest concern is actually house wiring in the future. As we go higher and higher in wattage and current draw from PSUs, when are we going to need dedicated lines in our houses for this stuff. I mean 1000W PSUs pull about 13 Amps already by themselves. My computer room circuit has a 20 AMP breaker. Soon I will have to sit in the dark with no heat.
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The heat issue should be covered by that kickass computer!
 
Dan_D said:
You can see the power requirements by two different high end rigs. As you can see neither one of them would need a 800watt+ PSU in their test configurations.

http://www.hardocp.com/article.html?art=MTQ1OCw3LCxoY29uc29sZQ==

Intel actually recommends a 1kw PSU minimum for that setup and 1200watts for a dual GPU configuration. They also recommend 1600watts for four GPUs. Obviously the actual requirements aren't nearly that bad.
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I was actually really worried about my power consumption after using some of these so called "power calculators". In the end I bought a "KIll-o-watt" meter. Found out that my dad's E6750 system was running 100 watts at idle. He is using integrated graphics iirc. These 1000 watt PSUs are insane over kill. I wish the feds would come out and start removing the PSUs from the market that can't generate what they claim they can.
 
vengence said:
I was actually really worried about my power consumption after using some of these so called "power calculators". In the end I bought a "KIll-o-watt" meter. Found out that my dad's E6750 system was running 100 watts at idle. He is using integrated graphics iirc. These 1000 watt PSUs are insane over kill. I wish the feds would come out and start removing the PSUs from the market that can't generate what they claim they can.
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Well they aren't always overkill. I like to keep PSUs operating at 50%-60% output at most. This will keep the PSU from being overly stressed. I think what people should do is buy quality PSU's that can out put twice the demand they'll actually place on it. For some 1kw is reasonable. For most people it is overkill.
 
I'll just chime in.

Ultra X3 1600w ftw!

(Q6600, 4GB, 10 hdds (3 IDE, 7 SATA), 2 opticals (1 IDE, 1 SCSI), dual 8800GTX's (Tri-Sli maybe), 6 PSU-Powered USB Devices (5w each), 3 PSU-Powered FireWire devices, 1x120mm, 4x 140mm, and a 44Lph pump)

I spend too much Money..:(
 
FireGS said:
I'll just chime in.

Ultra X3 1600w ftw!

(Q6600, 4GB, 10 hdds (3 IDE, 7 SATA), 2 opticals (1 IDE, 1 SCSI), dual 8800GTX's (Tri-Sli maybe), 6 PSU-Powered USB Devices (5w each), 3 PSU-Powered FireWire devices, 1x120mm, 4x 140mm, and a 44Lph pump)

I spend too much Money..:(
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You would likely be hitting 1000watts or so with 3-Way SLI and that setup. 3-Way SLI and 4 hard drives, with 2 optical drives and an overclocked Q6600 with a similar amount of fans pulls only around 770watts.
 
Youre right, not when Idle, but when Im working with sound, and Im streaming samples 100% load on all 10 HDDs, and all USB/FW devices, And Max CPU, filled Ram, and Quad Monitors for Mixing.... I'd rather not take a chance.
 
FireGS said:
Youre right, not when Idle, but when Im working with sound, and Im streaming samples 100% load on all 10 HDDs, and all USB/FW devices, And Max CPU, filled Ram, and Quad Monitors for Mixing.... I'd rather not take a chance.
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Trust me. You wouldn't need a 1600watt PSU. You would be fine with a 1kw or 1200watt unit. Your video cards will pull more power than anything else and working with video editing and banging the shit out of the drives with data transfers probably won't happen while your gaming. Therefore your power consumption won't likely get above 5 or 6 hundred watts. When gaming you'll see the largest increase in power usage but even then it shouldn't break 800watts.
 
Dan_D said:
Trust me. You wouldn't need a 1600watt PSU. You would be fine with a 1kw or 1200watt unit.
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Yep, you're right on that one, but I got a FANTASTIC Deal on this one. $350 (Vs $500+ retail)

the [H] review sold me on it.
 
FireGS said:
Yep, you're right on that one, but I got a FANTASTIC Deal on this one. $350 (Vs $500+ retail)

the [H] review sold me on it.
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There is nothing wrong with having more than you need. I don't need the 1200watts I've got now available at my disposal. I bought it because it was a damn good PSU and for no other reason.
 
Dan_D said:
This comes from video card manufacturers overstating the requirements because they know most PSUs on the market are shit and can't out put near what they are rated for. Rather than telling you to buy a quality 500-600watt PSU for virtually every high end configuration, they say 800watt plus hoping it gives enough of a safety net to eliminate most power supply problems.
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QFT!
 
Im using a Thermaltake 430W PurePower for my system and its been doing fine. I am sure the cheapos are fine for your basic systems.
 
Chombo said:
Im using a Thermaltake 430W PurePower for my system and its been doing fine. I am sure the cheapos are fine for your basic systems.
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Well I wouldn't recommend a el-cheapo supply. That shouldn't be confused with low wattage. A good low wattage PSU is fine for most builds. However if there is only a slight difference in price between say a 430watt and a 520watt PSU, I'd say go ahead and grab the 520watt just in case. (Assuming they are equal aside from wattage.)
 
Dan_D said:
Well I wouldn't recommend a el-cheapo supply. That shouldn't be confused with low wattage. A good low wattage PSU is fine for most builds. However if there is only a slight difference in price between say a 430watt and a 520watt PSU, I'd say go ahead and grab the 520watt just in case. (Assuming they are equal aside from wattage.)
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I was referring a power supply on a basic Dell that does not even have a GPU.
 
Chombo said:
I was referring a power supply on a basic Dell that does not even have a GPU.
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Again, as long as it is a quality PSU, it shouldn't matter. The $25 400watt+ PSUs are shit and you'll be lucky if the damn thing lasts six months and even luckier if it doesn't kill any hardware when it goes tits up.
 
Like the 6200 I bought for a friend that said it needs 18amps on the 12 volt line...... right.....
 
Dan_D said:
Again, as long as it is a quality PSU, it shouldn't matter. The $25 400watt+ PSUs are shit and you'll be lucky if the damn thing lasts six months and even luckier if it doesn't kill any hardware when it goes tits up.
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I guess for me cheapo is like $50 bucks or so. I am definitely not willing to spend $100+ on a system like that (especially when its not mine).
 
Chombo said:
I guess for me cheapo is like $50 bucks or so. I am definitely not willing to spend $100+ on a system like that (especially when its not mine).
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Agreed. Not every quality PSU is $100.
 
I had a cheapy 450w powering the last few computer builds of mine and it worked flawlessly, only reason I upgraded was because I won an Ultra x3 800w at PDXLAN. :)

Now I know Modular PSU's are awesome
 
I've always been skeptical of these ginormous power supply requirements. I've never had a problem with stability even over hours of intense gaming on both my previous rig (opty 170 oc'd etc.) and current rig (see signature).

This Enermax Liberty 400 Watt has been a rock solid trooper. Last time i measured, idle draws were 219, load was 330. But that was a whole rig ago, with an x1800xt pe. i would love to get a kil-o-watt and test again.

Would a 500 Watt be better? maybe. but i see no reason when the status quo works well.
 
r00k said:
I've always been skeptical of these ginormous power supply requirements. I've never had a problem with stability even over hours of intense gaming on both my previous rig (opty 170 oc'd etc.) and current rig (see signature).

This Enermax Liberty 400 Watt has been a rock solid trooper. Last time i measured, idle draws were 219, load was 330. But that was a whole rig ago, with an x1800xt pe. i would love to get a kil-o-watt and test again.

Would a 500 Watt be better? maybe. but i see no reason when the status quo works well.
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I had an Enermax Noisetaker 600watt that I smoked in about 2 months on this system:

Case: Coolermaster Stacker STC-T01
PSU: Enermax Noisetaker 600watt
Motherboard: Tyan K8WE (S2895)
Processor(s): 2x AMD Opteron 254 (2.8GHz) (Socket 940)
Memory: 5GB (2x512MB, 4x1GB) Corsair Registered ECC PC-3200 DDR400 DIMMs (2x512MB, 4x1GB)
Graphics Card(s): 2x BFG 7900GTX 512MB OC cards in SLI
Sound: Creative Labs Sound Blaster Audigy 2 ZS
LSI MegaRAID U320-2 PCI-X Ultra 320 SCSI Controller
Hard Drives: 4x 74GB Seagate Cheetah 10,000rpm Ultra 320 SCSI drives
Hard Drives: 2x 74GB Wester Digital Raptor 10,000rpm SATA 150 drives
Hard Drives: 2x 300GB Maxtor Diamond Max 10 7200rpm SATA II/300 drives
Optical Drives: Plextor 720SA SATA DVD-R/RW drive

I then switched out the Enermax for two Antec Neo HE 550watt units and ran them in tandem.
 
Dan_D said:
I had an Enermax Noisetaker 600watt that I smoked in about 2 months on this system:

Case: Coolermaster Stacker STC-T01
PSU: Enermax Noisetaker 600watt
Motherboard: Tyan K8WE (S2895)
Processor(s): 2x AMD Opteron 254 (2.8GHz) (Socket 940)
Memory: 5GB (2x512MB, 4x1GB) Corsair Registered ECC PC-3200 DDR400 DIMMs (2x512MB, 4x1GB)
Graphics Card(s): 2x BFG 7900GTX 512MB OC cards in SLI
Sound: Creative Labs Sound Blaster Audigy 2 ZS
LSI MegaRAID U320-2 PCI-X Ultra 320 SCSI Controller
Hard Drives: 4x 74GB Seagate Cheetah 10,000rpm Ultra 320 SCSI drives
Hard Drives: 2x 74GB Wester Digital Raptor 10,000rpm SATA 150 drives
Hard Drives: 2x 300GB Maxtor Diamond Max 10 7200rpm SATA II/300 drives
Optical Drives: Plextor 720SA SATA DVD-R/RW drive

I then switched out the Enermax for two Antec Neo HE 550watt units and ran them in tandem.
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What was that for??? The Space Shuttle or something?? damn.
Anyway, back to cheeep. I had a little bitty e-machine folding away 24/7, that's all it did and about 3 months in, the PSU (300W) went south and took the whole system with it.
Even for folding rigs, I usually get 400W Forton PSUs......dont need much, but need reliability.
 
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