Power Supplies

Re: PSU utilization myths debunked!

Yellowbeard — Tue, 04 Sep 2007 18:58:48 GMT

** I asked the PowerGuy if he had any data to support the "a bit longer" claim since the HX series is still 81% efficient @ 80-100% loads. If those high loads do affect the life of the psu surely there would be data to support it. [Quote/]

I'm sure the data is buried with the PSU engineer guys that did the R&D on our HX series. The basic thing to keep in mind that virtually any amplification circuit or conversion circuit (sound amplifiers, PSUs, etc) as well as mechanical devices (combustion engines are a good example) have a "sweet spot" or optimum operating range. Above or below that optimum range, their efficiency and potentially their lifespan will decline. This is especially true above this optimum point as heat and current is higher. Also, MTBF is typically given at 25c. MTBF decreases somewhat at higher operating temps just as efficiency does.

Re: PSU utilization myths debunked!

quietus2064 — Mon, 03 Sep 2007 19:26:34 GMT

I am going with either the silverstone op1000, Thermaltake 1200, or the new X3 1600. Yes 1600 watts. But to pusth it to 1600 watts you have to have a dedicate 20amp line from the wall. Hardocp did a good review on it. The x3 1600 sells for around $400.00. It is single rail 117amps. The thermaltake 1200 and the Silverstone OP1000 has better efficiency. The thermaltake never dropped below 82% even with a 8 hour torture test at full load.

Re: PSU utilization myths debunked!

Plasoul — Mon, 16 Jul 2007 23:54:07 GMT

Thank you for the info EliteKiller, it will definitely help a lot of us here, I believe the guys that work with the psu manufacturers I think most of them are really hiding the real facts of power supplies I really hate marketing I understand its there job but it really sucks when there ether lying to us or hiding stuff !

Re: PSU utilization myths debunked!

EliteKiller — Fri, 13 Jul 2007 00:09:55 GMT

I received a response from the Corsair PowerGuy and updated the OP. I also received a reply from OCZ Ryder, but he said "I am not sure I understand what you want to know?" which was disappointing.

Re: PSU utilization myths debunked!

lowboy — Thu, 12 Jul 2007 03:27:13 GMT

I don't know if it would help but I can get you to OCZ tech support(Ryder or Andy) and Yellowbeard here on forum is Corsair tech support. Also may be able to get you in touch with David Hammock which does testing for several PSU makers. If I can help let me know. So it seems the Corsair guys recommendation correlates with my past recommendations good to know.

Re: PSU utilization myths debunked!

EliteKiller — Thu, 12 Jul 2007 03:01:38 GMT

lowboy:
Hopefully on the other PSU manufactures you emailed tech support and not sales as sales will tell you anything. As tech support has the knowledge and background to support it.

Enermax was contacted using the online support ticket and technical support was chosen for the department. I was receiving cc'ed responses to my email that appeared to come from sales, but if I tried to reply it would change to webmaster@enermax.com.

Re: PSU utilization myths debunked!

lowboy — Thu, 12 Jul 2007 02:39:39 GMT

Hopefully on the other PSU manufactures you emailed tech support and not sales as sales will tell you anything. As tech support has the knowledge and background to support it. This will be interesting to see what tech support says. I'm glad you did this I know what they have told me in the past but will be nice to see how they reply. But please do get tech support and not sales responses. Also just a note on the PSU recommended list that you posted from Xtreme systems was a rip off of David Hammocks PSU list and not a Original by the poster but is a good list and has been added too.

Re: PSU utilization myths debunked!

contrvlr — Wed, 11 Jul 2007 11:23:03 GMT

DTNguyen107:

http://www.xtremesystems.org/forums/showthread.php?t=108088

^^^A must see link^^^

http://www.tomshardware.com/forum/redir.php?forum=hardware&supercat=&catname=&numeropost=198276&start=0

Links about PSU and Tiers. Hope it helps.

The xtremesystems link is provided in EliteKillers sticky at the top of the board and the toms hardware link is no longer any good.

Mpilchfamily, the author of the PSU 101, has moved on due to disagreements with the mods, and took his sticky with him. He can be found at xcpus.com.

Re: PSU utilization myths debunked!

DTNguyen107 — Wed, 11 Jul 2007 08:24:21 GMT

http://www.xtremesystems.org/forums/showthread.php?t=108088

^^^A must see link^^^

http://www.tomshardware.com/forum/redir.php?forum=hardware&supercat=&catname=&numeropost=198276&start=0

Links about PSU and Tiers. Hope it helps.

Re: PSU utilization myths debunked!

Ynot — Wed, 11 Jul 2007 08:02:36 GMT

That's the importance of quality.

Re: PSU utilization myths debunked!

SovetCryptix — Tue, 10 Jul 2007 01:10:20 GMT

I'd have to say I agree, if you have the correct wattage and a good/high quality PSU, you're set. If the PSU is a good quality one, you really don't need the wattage buffer, it's just wasted.

I'm running a 530W Hiper. (Oh how I LOVE modular)

PSU utilization myths debunked!

EliteKiller — Tue, 10 Jul 2007 00:23:52 GMT

For quite some time people have been recommending high wattage / high quality psu's where they weren't required. I came across an article on Overclockers.com a while back where the author used a 380W psu in a mid/high-end rig and measured the psu and wall loads. As it turns out a member on the OC forums did the exact same thing and posted pictures of the process.

A C2D E6600 @ 3.4GHz, 975x mobo, 4x1GB DDR2, 8800GTX, 2 HDD, 1 DVDRW, 4x low power fans powered by an Antec EarthWatts 380 only draws 380W from the wall while under full burn-in and gaming load. Therefore the psu is under a 320W load which in turn is an 84% load on the psu. How often are you going to be under this kind of worst case scenario load? Average load would be around 70%. According to JonnyGURU the EarthWatts is capable of 80% efficiency @ 20-100% loads. How long will this psu last? We already know that not all psu's are created equal, and there are plenty of high end psu's that can sustain an 80-100% load 24/7 (yes, that is continuous) as long as the temps are kept in range.

http://www.pcpower.com/technology/myths/

2. DON'T BE MISLED BY EXAGGERATED WATTAGE CLAIMS To properly compare power supplies, wattage claims must state the maximum ambient temperature for continuous, full-load operation. Unfortunately for the consumer, this information is usually withheld, opening the door for manufacturers to exaggerate their wattage claims. They do so by assuming an unrealistic ambient temp of only 25°C (77°F), even though the actual internal power supply temp is at least 40°C (104°F). Since the proper full-load rating is 15°C higher for home use and 25°C higher for industrial use, these power supplies produce 33%-50% less power than their advertised ratings. See the derating chart on the right. Elevated Temperature Testing
Turbo-Cool 510 spec: full load @ 50°C. "500W" Home PSU spec: full load @ 25°C, no load @ 70°C.

As you can see it's important to choose a psu that offers continuous output @ 50C. The number of amps on the 12V rail(s) is also important. Some psu's claim to have multiple 12V rails but are in fact one single rail (preferred).

8. ARE MULTIPLE 12-VOLT RAILS BETTER THAN A SINGLE 12-VOLT RAIL?
With all the hype about multiple 12-volt rails (ads claim that two rails is better than one, five is better than four, etc.), you’d think it was a better design. Unfortunately, it’s not!

Here are the facts: A large, single 12-volt rail (without a 240VA limit) can transfer 100% of the 12-volt output from the PSU to the computer, while a multi-rail 12-volt design has distribution losses of up to 30% of the power supply’s rating. Those losses occur because power literally gets “trapped” on under-utilized rails. For example, if the 12-volt rail that powers the CPU is rated for 17 amps and the CPU only uses 7A, the remaining 10A is unusable, since it is isolated from the rest of the system.

Since the maximum current from any one 12-volt rail of a multiple-rail PSU is limited to 20 amps (240VA / 12 volts = 20 amps), PCs with high-performance components that draw over 20 amps from the same rail are subject to over-current shutdowns. With power requirements for multiple processors and graphics cards continuing to grow, the multiple-rail design, with its 240VA limit per rail, is basically obsolete.

PC Power and Cooling is once again leading the industry. All of our power supplies now feature a large, single 12-volt rail. The design is favored by major processor and graphics companies, complies with EPS12V specs (the 240VA limit is not a requirement) and is approved by all major safety agencies such as UL and TUV.

- I decided to contact several reputable mfg's for their input.
_______________________________

-----Original Message-----
From: Enermax [mailto:sales@enermaxusa.com]
Sent: Monday, July 09, 2007 6:38 PM
To: elitekiller
Subject: [TSU-4450]: psu utilization questions

In this case our Infiniti power supply would be capable of handling 80% to 100% for any given number of time, and it can do it for 24/7. So you can say that if you have a quality power supply, you can run up to 80% or 100% load and still be within the voltage specs. In the end you don't really need a bigger power supply then your system can use. You can check the status or reply to this ticket online at http://www.enermaxusa.com/catalog/ticket_status

Please let us know if we can assist you any further

www.enermaxusa.com
_______________________________

Power Guy
Corsair Power Guru

Thanks for the message. I actually recommend a 40-70% load if possible. Here's why.

This is the efficiency curve of the HX series, which is somewhat common for 80+ rated PSUs. The idea is that you want to be at that peak or near it as much as possible. So yes, you could be at 20% or 80%, but the problem with being very close to max load on a PSU is that it stresses components. For maximum lifespan, matching a 40-70% load is the best efficiency and will allow the PSU to last a bit longer.

** I asked the PowerGuy if he had any data to support the "a bit longer" claim since the HX series is still 81% efficient @ 80-100% loads. If those high loads do affect the life of the psu surely there would be data to support it.
______________________________

Don't get me wrong, I'm not trying to tell everyone to run out to purchase a bare minimum psu. However If you aren't running SLI or a high-end system there is absolutely no reason to purchase a >500W psu unless:

you have money to burn
you're considering a mediocre or mid-range psu
you simply want additional headroom for future expansion (SLI, CrossFire, HD 2900XT, multiple high wattage cpu's, exotic cooling, etc.)

I'll update this thread as I receive responses from other psu mfg's. Feel free to post your thoughts as well. The next question you'll probably be asking is how to tell if the psu that you've picked out is high quality or a junker. You cannot judge a psu on name alone, so here is the Recommended PSU List