How reliable is this site?

[Noema]

I am building a new rig soon (Summer) and I am looking for a nice power supply to provide the juice.

I found this site which seems very nicely laid out...I tried my projected rig (C2D E6600; 2GB DDR2 RAM, 8800GTX -if prices have dropped by then; I might consider ATI as well if it offers better bang for the buck once R600 is released; I will not be overclocking) and it calculated an usage of about 380W under load, which sounds reasonable. I was thinking of a 600W power supply and for a while, worried about that not being enough; hopefully it will and this site seems to confirm it.

However, how accurate is this? What do the pundits think about it?

Thanks!

 

[moonbit]

From everything I've heard, that's the go-to site for that sort of thing. It's very comprehensive and takes into accounts things such as if you're going to leave your rig on 24/7.

 

[bob4432]

Originally posted by: Noema
I am building a new rig soon (Summer) and I am looking for a nice power supply to provide the juice.

I found this site which seems very nicely laid out...I tried my projected rig (C2D E6600; 2GB DDR2 RAM, 8800GTX -if prices have dropped by then; I might consider ATI as well if it offers better bang for the buck once R600 is released; I will not be overclocking) and it calculated an usage of about 380W under load, which sounds reasonable. I was thinking of a 600W power supply and for a while, worried about that not being enough; hopefully it will and this site seems to confirm it.

However, how accurate is this? What do the pundits think about it?

Thanks!

what is more important is the quality of the psu than the advertised W rating. so get a quality 600W and you will be fine, get a pos 600W and you will probably have issues. good brands are seasonic, enhance, enermax, pc&p, fsp - have a look at http://www.jonnyguru.com/ for reviews of different psus.

 

[Roguestar]

I think it's quite accurate, perhaps a little erring on the side of caution. Good enough to gauge a purchase by, if you look for around that wattage in a good brand name like Seasonic or Enermax.

 

[Aluvus]

It's a decent estimate, and better than guessing blindly.

However, quite depressingly, the "lite" version provides no information on how the load is actually distributed between the power rails. And that severely damages its actual value. If you want a fully-functional service, you're expected to pay for it. The site even makes clear the situation:

The recommended total Power Supply Wattage gives you a general idea on what to look for BUT it is NOT a crucial factor in power supply selection! Total Amperage Available on the +12V Rail(s) is the most important, followed by the +5V amperage and then the +3.3V amperage.

 

[oynaz]

People tend to greatly overestimate the needed PSU. 600 watts is way more than you will ever need with your build. Get a good 450 watt PSU, and you are set.

 

[HannibalX]

Wow, they are charging for the site now? Boo.

 

[Boyo]

I didn't know they were now charging for the site either. But it is a pretty good indication of what kind of PSU you are going to need in your rig. If you are waiting on the R600, I would hold off until you know what the wattage requirements will be for the card.

 

[Noema]

Originally posted by: Pale Rider
Wow, they are charging for the site now? Boo.

Only to check the Ampere requirements on each of the rails, but you can check wattage usage in the free version.

 

[BurnItDwn]

I'd say it looks like it's overestimating ...
for my computer, that site is suggesting over 500 watts, and my 430watt Enermax has been chugging away for years without ever a problem.
(overclocked socket 939 AMD x2 4200+, 2gb ddr, x1800xt, 5 hard drives, dvd burner, pci ide card, pci nic)

 

[piasabird]

Total Wattage is not very good because a power supply has a rating for all the different voltages.
12v
5.5v
3.3v
Whatever.

Uses Voltage:
Cooling fans
CPU
RAM
MOTHERBOARD
USB
CDROM
HARD DRIVE
KEYBOARD
SOUND CARD/SPEAKERS
PRINTER PORTS
Whatever else.

 

[Mashed Potato]

My 2 cents:

I am currently running the rig you are looking into and researched/asked around about which brand psu to buy. I ended up getting the corsair 620w which has been great. I was a little worried that it would not handle a moderate/extreme overclock, but i pushed my vcore up to 1.45, my ram is 2.25v, and I overclock my gtx to 650/1013 while gaming with no problems whatsoever. As oynaz replied, you should be fine with a quality 450w psu if you do not plan on overclocking. btw corsair makes a 520 as well.

-mashed

 

[bob4432]

Originally posted by: BurnItDwn
I'd say it looks like it's overestimating ...
for my computer, that site is suggesting over 500 watts, and my 430watt Enermax has been chugging away for years without ever a problem.
(overclocked socket 939 AMD x2 4200+, 2gb ddr, x1800xt, 5 hard drives, dvd burner, pci ide card, pci nic)

my rig is very similar to yours and my antec 480W is not having any issues whatsoever (i have added 2xpata hdds since i have updated my sig info and another optical drive)

 

[Ken90630]

Originally posted by: oynaz
People tend to greatly overestimate the needed PSU. 600 watts is way more than you will ever need with your build. Get a good 450 watt PSU, and you are set.

Agreed. :thumbsup:

For whatever reason, OP, that estimate you came up with is way off. PSUs like that are about marketing, not real-world needs.

Read this if you want to see why. Particularly notable, IMHO, is a paragraph in the grey box about halfway down the page, dated two days ago, that reads, in part:

"The ATI X1950XTX / overclocked Pentium D950 system information was added to round out the data ... The 1950XTX still remains about the most power hungry graphics card on the market today. The Pentium D950 actually has a higher TDP (130W) than most current CPUs; we made it run hotter by overclocking and overvolting 10%. This system has a higher DC power demand than just about any single vidcard, single CPU system you can build today. Yet, the total DC power demand is just 256W. (Note: It runs perfectly stable with a new very high efficiency 350W power supply from Seasonic.)

I'm sure the marketing folks at PSU companies would love to take your money, but you'd be hard pressed to build a sane system that would draw anywhere near even 450 watts, never mind 600. As I understand it, the key is to get a high quality PSU with sufficient amps on the 12V rail(s) and you're good to go. Total wattage specs are almost meaningless in many instances, particular with cheap PSUs whose power output plummets when they're under load and hot. Also, many PSUs actually perform poorly , in terms of their efficiency, if your system draw on them is too far under their rated output capability. So trying to "be safe" by buying an overpowered PSU actually gives you worse performance than if you'd gotten the 'right' PSU for your actual system needs. (There's an explanation of this is in that article as well -- on another page.) A notable exception is the Seasonic S12 series PSUs, which reportedly perform at high efficiency even when system draw is low. There may be others as well, but I'm not personally aware of them.

My advice is to buy a high-quality-but-lower-powered PSU and save your money for more important things like pizza and :beer: .

EDIT: By "be safe," as I mentioned above, I'm not referring to personal safety (like from shock or something). "Safety" in this instance referred to having room for upgrades and/or future technology. Heh heh -- more on that in my subsequent post below.

 

[oynaz]

Wise words.

I should add that high quality PSUs can safely run under loads far greater than their rating. BurnItDwn's PSU can probably handle about 1Kw safely.

 

[Icepick]

That site overestimates the power requirements. I think that the reason goes back to the strategy used by power ratings to assume the worst possible scenario - that a person is using a cheap 550W power supply from a brand like Aspire. Look at Anandtech's own recent video card reviews.

http://www.anandtech.com/video/showdoc.aspx?i=2931&p=7

The load power draw for a top of the line system with a 8800GTX barely draws 300W. A well built 380W-450W power supply from a quality manufacturer will be fine. Just make sure there are plenty of combined amps on the 12V rails.

 

[bob4432]

personally i would go on the side of caution especially if building a new rig. non-sli gtx and a matching machine - get a good 550-600W for future and also piece of mind - quad core, possible sli, next gen gpu, etc. is it needed, no but if it is only $30-$50 more why worry about it when your gpu alone is $500.

 

[oynaz]

Originally posted by: bob4432
personally i would go on the side of caution especially if building a new rig. non-sli gtx and a matching machine - get a good 550-600W for future and also piece of mind - quad core, possible sli, next gen gpu, etc. is it needed, no but if it is only $30-$50 more why worry about it when your gpu alone is $500.

Generally a bad idea. Most people will never need a 600 watt PSU. Get a quality 350-450 watt PSU instead.

 

[Ken90630]

Originally posted by: bob4432
personally i would go on the side of caution especially if building a new rig. non-sli gtx and a matching machine - get a good 550-600W for future and also piece of mind - quad core, possible sli, next gen gpu, etc. is it needed, no but if it is only $30-$50 more why worry about it when your gpu alone is $500.

I would respectfully disagree (no offense, bob4432). As I mentioned in the next-to-last paragraph of my earlier post, many PSUs don't perform at their rated efficiency if the load on them is too far under their rated output capacity. In other words, running a 600-watt PSU when the system draw on it is only, say, 250 watts, will result in poor efficiency with most PSUs. Poor efficiency means much of the incoming AC voltage is not being converted to DC (to power the system's components) and is therefore being wasted and converted to heat instead. In turn, as the heat inside the PSU grows, its power output decreases. So not only do you have extra heat in your system, but the PSU's output is being 'dragged down' as well. Again, that article I linked to earlier explains this in more detail.

As I also mentioned, the Seasonic S12 series is notable for its ability to maintain its efficiency performance even when being run at a load well under its capacity. There may be other PSUs that can do this as well, but AFAIK, most don't.

I understand the idea of "future-proofing," but even if the OP buys a high quality PSU like, say, a Seasonic S12-430, he's still gonna have at least 100W of 'cushion' or breathing room for future technology/upgrades. Like Icepick said in his post, "The load power draw for a top of the line system with a 8800GTX barely draws 300W." I personally don't see the need for having 200 or 300 watts :Q of breathing room for the "future" or "peace of mind," particularly when you consider the tradeoff that the PSU is likely not going to be performing anywhere near its rated efficiency. But hey, to each his own. I'd save that extra $30 or $50 to put towards the next PSU upgrade several years down the road that, hopefully, will again be an appropriate PSU for the system it's used in. Or put it towards a better vid card or faster CPU or something, which will yield genuine benefit. Or, like I said, pizza and :beer:.

 

[Slammy1]

A quality lower wattage to be sure, the efficiency is a great thing. But, if you don't mind an extra few bucks, a larger PSU is nice. I bought a larger 480W about 4 years ago I figure will hold me through one more upgrade. My Enermax 350 was too big at the time, but has had a fine lifetime first in my PC now a friend's. Then again, there's headroom then there's bragging rights, and if you tend to upgrade completely there's not much argument for going very high (aside from concerns during troubleshooting).

 

[bob4432]

no offense taken

i base my recommendations on my personal and friends upgrade pattern, which is usually something majory every 9-18mos (in my case cpu went from a 75Mhz -> 450MHz -> 750MHz -> 1GHz -> xp2000 -> 2.8C P4 -> Opty 144 -> X2 3800, and gpu went - voodoo 3000 -> ti4200 -> 9800pro -> x800xtpe -> x1800xt), for me the next step will be moving to ddr2 and whatever cpu brand is better at the time. so i know my stuff gets update pretty often and i have in the past purchased psu that were more in line with what i needed at the time only to buy another one 9mos later. soon i had bunch of psus lying around and i was handing them out to friends as i no longer had a use for them, but if i would have bought a larger 1 farther back, i would have saved myself hundreds of $$$ throughout the course, not thinking i would upgrade as much as i did.

maybe since now computer hardware is as fast as it is the upgrade cycle will slow down, but in my case if i start to do video work again i will pick up a c2d and then a c2q since i would make more $$$ in saved time than the processor costs, so the added headroom of a larger psu is nice. and it is not like i am saying pick up a 1KW unit, that would be ridiculous, so i guess it all depends on the person and like i said, my recommendations do come my from my ethnocentric view

 

[Moose1309]

I think the power requirements of PC's will level off or even drop. Then again, at the really high end they may continue to creep up in general as the functionality of PCs increases, but not too horribly steeply. A lot of the increase in power requirements over the last years has come from a marketing feedback loop, more than real requirements. For instance, for a given video card they would say "450W PSU required/recommended," not because the card draws anything more than 50W under full load, but because there were a lot of shoddy PSU's out there. the next thing that happened was a bunch of PSU companies released crappy PSUs that were rated at 450W, and videocards started recommending even more power.

In other words: a good PSU is very important. However high wattage rating != Good. Buy whatever wattage rating you want, but make sure it's a good PSU whatever you do. Read the sidebar on page 3 of the SPCR article called "POWER SHMOWER: or How PSU Power Ratings Mean Almost Nothing" and you'll see what I mean remember that something like the Seasonic S12-330 will probably power any single-card machine out there AFAIK, and it costs $60. If I were running an 8800GTX, I would probably go for the 500, just so I had the dual connectors and for "breathing room," but that's it.

 

[Ken90630]

Originally posted by: bob4432
no offense taken

i base my recommendations on my personal and friends upgrade pattern, which is usually something majory every 9-18mos (in my case cpu went from a 75Mhz -> 450MHz -> 750MHz -> 1GHz -> xp2000 -> 2.8C P4 -> Opty 144 -> X2 3800, and gpu went - voodoo 3000 -> ti4200 -> 9800pro -> x800xtpe -> x1800xt), for me the next step will be moving to ddr2 and whatever cpu brand is better at the time. so i know my stuff gets update pretty often and i have in the past purchased psu that were more in line with what i needed at the time only to buy another one 9mos later. soon i had bunch of psus lying around and i was handing them out to friends as i no longer had a use for them, but if i would have bought a larger 1 farther back, i would have saved myself hundreds of $$$ throughout the course, not thinking i would upgrade as much as i did.

Hi, Bob,

I understand your line of thinking here completely. What I would assert, however (and again, no offense ), is that maybe you thought you needed to upgrade some of those earlier PSUs when maybe you didn't. Realistically, if your previous PSUs were high quality 300-watters or greater, and had enough amps on the 12V rail, you could have continued to use them with your upgraded CPUs and vid cards with no problems. As recently as a couple years ago, it was pretty difficult to even build a PC that would draw much over 200 watts. I had a phone discussion with one of the engineers at PC Power & Cooling about this when I was building my first rig, and didn't really understand power requirements, and that's what he explained to me. According to him, the reason they and other companies were making 300-watt PSUs and higher (I asked ) was for the proverbial "breathing room for future expansion." This was around the time the P4s had come out and CPU power requirements were on the rise and we didn't know how those requirements were gonna continue to evolve.

The point I'm trying to make is that even the high quality 400-watt PSUs of today have plenty of "breathing room" for expansion already, since the draw from even high-end, cutting edge single-card system is typically not going to be above even 300 watts (if that). Obviously, it's possible to build a machine with dual vid cards, the fastest chip available, and a whole slew of drives and cathode lights and 8 fans or something that might push peak power demand higher, but how many people are gonna do that? For hardcore gamers running SLI, quad core, and O/Cing the heck out of both, sure -- go for gobs of power. But for most "mainstream" users, even average gamers, that power is prolly gonna go unused.

EDIT: happy medium's link to AtomicMPC's site, showing the ravenous power requirements of some of the new and upcoming cards, has shown me that my original paragraph here was off the mark. My humblest apologies.

In the end, what really matters in a PSU is the amperage available on the 12 rail(s), and the overall quality of the PSU, not total wattage[/i]. Awhile back (~ a year or two ago?) there was another thread on this subject in which I issued a challenge for someone -- anyone -- to post a profile of system they could build that would draw more than 300 watts (or something like that -- I forget the exact number I used) in real world conditions. The challenge included posting the wattage calculation they would use to arrive at their conclusion. Not one person accepted the challenge. That challenge could be answered successfully today with a quad-core, SLI, overclocked system, but it would take a system like that to do it. Per Icepick's link earlier in this thread, Anandtech's own review shows the highest-end single vid carded system only drawing 301 watts.

I'd venture that many people reading this post (or the article over at SPCR.com) might even realize that they don't really need a higher-powered PSU. But they'll buy one anyway because they don't really understand power requirements and they think they'll be "playing it safe" by having extra power "just in case." To each his own, but I think a lot of people, particularly all but the most hardcore gamers, are just wasting their money on 500- and 600-watt PSUs. IMHO, of course.

EDITED for corrections and some re-wording.

 

[happy medium]

I agree with the "play it safe people".

Heres a Corsair 620 watt psu for 124.99$ that will handle 2 8800gtx in sli. I'm sure it will handle the r600 also.

http://www.zipzoomfly.com/jsp/ProductDetail.jsp?ProductCode=373110

And heres the review

http://www.legitreviews.com/article/462/1/

Great psu for the price!:thumbsup:
I use the calculator for a reference. If my new system pulls 400watts, I'd go for a 600watt psu for future upgrades.

 

[Ken90630]

Originally posted by: happy medium
I agree with the "play it safe people".

Heres a Corsair 620 watt psu for 124.99$ that will handle 2 8800gtx in sli. I'm sure it will handle the r600 also.

http://www.zipzoomfly.com/jsp/ProductDetail.jsp?ProductCode=373110

And heres the review

http://www.legitreviews.com/article/462/1/

Great psu for the price!:thumbsup:
I use the calculator for a reference. If my new system pulls 400watts, I'd go for a 600watt psu for future upgrades.

Okay, wise guy , I have a few questions for you:

1) Would you say the system in that so-called "review" (not much of a review IMHO) is something many people are going to have? An overclocked, watercooled Intel QX6700 Kentsfield with dual GeForce 8800 GTX video cards in SLI (and a waterpump)? :Q Yeah, that's a realistic, real-world system to base PSU recommendations on.

2) What is that PSU's amp output on the 12V rail(s)?

3) You said, "If my new system pulls 400watts, I'd go for a 600watt psu for future upgrades." Okay, but since most PSUs don't run anywhere near their rated efficiency capability when run way under their load capacity, you're willing to accept much lower efficiency (and therefore more heat) just to have an extra 200 watts for the indeterminate possibility that you might need it down the road? 200 watts?

Oh, and the reason that system in your sig runs perfectly fine on an Enermax 350-watt PSU is that it's prolly drawing somewhere in the neighborhood of maybe 200 watts. How come you're not running a 500-watt PSU in that rig "just to play it safe"?

No offense intended here -- just trying to understand the thinking behind this.