linderman

Seasonic uses a tricky little method which makes their units "appear" to have isolated 12volt rails but when you see them actually draw more than 20amps off that 12volt leg / it becomes very evident as to the real deal

the single 12volt rail became necessay with video cards like the 8800 GTX and above power hogs, especially the sli combinations like that

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EquiNOX

Lindermann

Hmm, I am interesting to know what can a LQ PSU supply give effect to rest of system and components?

I been hearing things about suggesting a better PSU with fine brand name or higher prices? I mean Not everyone have $ to buy high/Top end PSU even if they are not game crazy.

Care to explain why is it best to get Better Q's PSU?

linderman

The specifications for the two Energy Plus models are identical except for the combined load on the +12V rail, just as it should be. In real use, this is really the only number that matters; real world conditions dictate that the vast majority of power is pulled from the +12V lines.

The fact that increased capacity only shows up as combined current on the +12V lines raises an interesting question: Just how separate are the four +12V lines. Some knowledgeable members of the SPCR forums have done some digging, and discovered that in reality there may only be one or two lines. The discussion is specifically about Seasonic's new M12 line and its rebranded twin from Corsair, but given its similarity to the Energy Plus series, many of the points apply equally to both series. Things get quite technical, but the summary is this:

Lines are only "separate" insofar as they have separate current limiters on each line. The original source is often (but not always) the same.
The purpose of having multiple rails is to limit the total VA from one line to 240VA, which means a limit of 240VA ÷ 12V = 20A on each line.
The circuit board does not identify contact points for either +12V3 or +12V4.
One user has reportedly been able to draw as much as 30~40A from a single cable set, which should certainly have tripped a current limiter if the rails were actually as specified. We were able to perform a similar test on the Energy Plus.
Only Seasonic knows for sure, but it seems quite likely that the four "separate" +12V lines are not separate at all, but are just there to satisfy the standard-setters at ATX12V and EPS12V. The practical consequences of having a single +12V rail are actually more positive than negative. While a small degree of safety is lost by isolating the rails, the convenience of not having to watch where each peripheral is plugged in outweighs the loss.

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linderman

The power supply needed depends on the spec of the system of course .............. but when you see low end power drawing specs supplied by builders like Dell, Gateway, Compaq etc etc etc come into the shop all the time with dead power supplies and dead motherboards resulting from those power supplies, please explain where the savings is in that equation ?

the number one killer of motherboards, memory sticks and hard drives is cheap defective power supplies ,,,,,,, like everything in life, you get what you pay for.

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patriothntr

aye, i had mentioned the "virtual" part in this post...you have a link to the SPCR article linderman? love a lil more reading...

OP: LQ PSUs are plain old bad news...they may work for a while, but will probably die on you sooner rather than later...and there is smaller chance of something else going as well. I have worked with many OEM computers (all mentioned above by linderman) and with stock components they tend to last okay...units left on die faster...the average life of a PC is limited.

Stick with a brand known for PSUs and you'll probably be ok...Antec, FSP, Seasonic, etc...and you can get a lower wattage PSU for a lower end system and be fine...Also check out Toms Hardware's latest articles...one of their system builds uses a Silverstone 400w PSU to power a 8800gt SLI setup.

EquiNOX

Lindermann: That's so True... I got your point! I am glad I you brought this up for my future knowledge.

PatriotHntr: Care to post link on article you re referring to?

patriothntr

linderman

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linderman

My only beef with the Tom's Hardware article is; it gives readers a false sense of comfort that can use low wattage units on higher end specs. A 400 watt unit like the Silverstone can power the rig for awhile, but its pushing that power plant to its limits for sure; they should have been responsible enough to publish the air temps of the exaust from that power supply when gaming with it! I bet it would have made a good second choice for hair dryer :)

another point of contention I have with the article is this :

review the big specs of the units which are labeled as "Nivdea SLI approved" for 8800GT's and 8800 GTX ........ then remove the power draw from the ONE extra card in that sli configuration from those sized "sli approved" units .................... does 400 and 500 watts end up as the answer to that equation ???????????????

http://www.slizone.com/object/slizone_build_psu.html

BTW: the PSU manuf has to bear the burden of cost for the Nvidea test qualification and it aint cheap .............. could well be called the "best of the best"

The Silverstone unit is a good quality unit for sure ...... but where is the savings in deliberately buying a silverstone 400 watt instead of say......... Toughpower 650 watt ?

I dont throw $$$$$ around either; if someone is tight for the budget, Hell; get a good high quality power supply that has muscle from the mwave.com / refurbs then if you have patience for one to be listed, you can get a toughpower 650, 700 or 750 or collermaster real power pro 650 or 750 for $80.00 or less ................. now beat that deal for that price .............

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magnethead

when i bought my toughpower, I planned ahead, knowing that i'm gonna leave the option out there to run 2 cards non SLI'd, and i didnt want to replace anything but the mobo when i did so. so i only looked at PSU's that had the SLI/crossfire designation.

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For proper support: what are you running? video card, cpu, m/board, ram, power supply, brand, wattage, any error message?
PCI-E requires 26 amps at 12 volts. That's a 650W PSU.
Power Supply Info and Selection . Info on thermal compounds & application . TEST PSU USING MULTI-METER

patriothntr

sorry...i don't really understand what you're trying to say here...think i figured it out below...let me know if i misinterpreted...

As far as heat goes, any gaming unit with twin cards is going to produce a lot of heat, especially the 8800gt with it's "heat up the case" cooler. So long as the PWM fan cranks up, and you have adequate case ventillation, life is good...

Lets see....650 (kingwin)-(105 (8800gt) + ~55 (extra load of 8800gtx))=~500w. Like you were saying, the SLI certification is much harder to get than real life...making the SLI cert the uber supplies.

You save money in a couple ways buyin the cheaper PSU. First you get the immediate savings...the 10-30 bucks less it costs...that's nothing special...but every bit is nice. Next is the power savings you will get over the next few years...Due to how the 80+ certs are given out, a PSU hit 20% load in order to get inside the efficiency curve. Say your computer is on, idling...Say you idle around ~150w...that means anything much bigger than 650w would put you outside that range...and start to hurt efficiency.

Now I do think that Toms hardware was pretty close to the limit with those 2x 8800gt cards in SLI...I would probably have gone with something slightly larger...in the 500-550w zone...but there's plenty of power to run a single 8800gtx or 4850.

dai

the corsair i recommend are single 12v rail and i would not use less than a 650 for 8800gt in sli

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linderman

I agree with you Dai / and such advice has kept me 100% out of the power supply problems with my warranties ......... I will never go back to the thin red line, it hurts the wallet too much

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