OCZ PSU 520W or 600W

[oandrew]

I read that (from here) the OCZ 520W is a recommended PSU for DFI. I wonder if the 600W is better, especially for SLI. I notice that the 520W version has only a single 33A rail for the 12V. Do I really need the two seperate rails such as that on the 600W for SLI? When are the two seperate rails really needed?

 

(NOTE: I am trying to find a PSU for my second rig)

[Angry_Games]

i prefer the 520w as it is a lot more silent (well, between mine anyway) and 520w of OCZ power is a lot of power

[Renegade87]

I read that (from here) the OCZ 520W is a recommended PSU for DFI. I wonder if the 600W is better, especially for SLI. I notice that the 520W version has only a single 33A rail for the 12V. Do I really need the two seperate rails such as that on the 600W for SLI? When are the two seperate rails really needed?

 

(NOTE: I am trying to find a PSU for my second rig)

 

In my opinion, OCZ PSU's are overpriced. Good product, but for roughly $200, (Powerstrem 600) overpriced. If you don't have a problem investing $200+ in a PSU (good investment in my opinion seeing as you may spend thousands building or rebuilding your Rig) why not get a psu that is rated at 650w max (will hit the full rated 510w at 50 degrees c) provides 34Amps (38Amps Max) on the +12v Rail, and maintain a documented +/-1% voltage regulation (lets see any OCZ match that!)? Look at the PC Power & Cooling Turbo-Cool 510 ASL for your Expert. Especially, if you're entertaining SLI. 125Wx2 in SLI can tax a PSU quickly.

[red930]

Enermax Liberties also work well according to many people here. Thats in my mind overpriced too (620w goes for 175 currently at the egg).. considering i can find a truepower 550watter for 90 bucks (i know its antec, but itll get the job done) i wouldnt buy it. but i dont have a job, so that hinders my spending.

 

my .02 cents.

[siresword]

I notice that the 520W version has only a single 33A rail for the 12V. Do I really need the two seperate rails such as that on the 600W for SLI? When are the two seperate rails really needed?

 

I was wondering about that too, do you need dual 12v rails? and are 33a enough on the 12v rail? even my junky aspire psu has "dual 12v rails, a 16a and a 18a" (thats what it said on the psu), and 16+18 = 34a...

[ComeUpon]

I've seen technodanvan talk about the the Fortron FX700 a lot, and for the price, if I say so myself, it really does look like an amazing PSU.

[Nautilian]

The reason why we have dual rails is because electrical isolation for noise and improved voltage regulation. Some devices, usually electromechanical ones having motors, produce noise spikes & voltage fluxuations, these can include pumps, compressors, fans, drives, lights (when turned on & off) and probably TEC’s & Peltiers. By putting these “noisy” devices, that often turn on & off, or at least often change their power (amperage) demands, on a separate rail we isolate them from the MoBo, CPU, Video Card(s) and the other electronic components that are sensitive to noise & sudden changes in voltage. This is a good thing!

 

Two rails are better than one. It depends on your system as to weather or not dual rails would actually be of any benefit. If yours is a simple system, with no exotic cooling, large disk arrays or flashing lights, then you would probably not benefit from dual rails.

 

Do not get confused between a dual rail PSU and a spliiter. In a dual rail design the PS has two transformer taps and control circuitry for two separate +12V rails. Using a splitter can be very helpful, especially if you split off your “noisy” loads very close to the PS, as this will lessen their effects on your more sensitive components, however the dual rail design would still be much better if you have a lot of “noisy” loads.

 

I remember reading this from somewhere, will try finding it so I can put the FULL article up. This is all I can remember from it.

 

Hope that helps

Naut

[Squid1]

Single-rail is better when your primary goal is to provide maximum stable power to one device or devices that are identical, such as one CPU or several CPUs. Typical examples are highly overclocked computers and multi-CPU systems (most established server PSUs have a single rail).

 

As mentioned, in theory dual rail is better from a noise standpoint, you can put noisy devices like harddrives, optical drives and fans on a separate rail and get more stable power on the rail going to your CPU. In my opinion, this is highly overrated. In almost all desktop systems the harddrive never powers up and down during options, CD-ROM access is very sporadic and you have neither enough harddrive nor optical drives to waste half the PSU power on. Most fans also have very low power and don't warranty major compromises on the CPU power.

 

Dual rail in practice is done because it is easier to provide high power cheap. In the example of the OCZ powerstream the maximum you can get on one rail is 520W total, which is not enough for high-end dual-everything systems.

 

There are higher powered single-rail PSUs but most of them are from the server/SMP segment and very loud.

 

BTW, is it true that the 600W Powerstream is louder than the 520W?

[PL4YD34D]

IMO the 600w has a different build quality and the 520w seems to have just that little bit more rail stability. but like was said earlier, the PC P+C 510 SLI is the king. (and ive just found somewhere in the uk that sells them, muwhahahaha)

[Nautilian]

Martin Cracauer, I must agree with you, however if one has to weigh up the total use of a PSU with todays technology, a DUAL rail PSU is the better buy. Also the luxury of running 2 PS's in one case is a bit difficult.

 

To get the range of PC P+C just go to www.frozencpu.com, they ship internationally!

 

Naut

[Squid1]

Martin Cracauer, I must agree with you, however if one has to weigh up the total use of a PSU with todays technology, a DUAL rail PSU is the better buy.

 

Not if you are like me and had a PCP&C 1 KW (!) not being able to power up a board of mine because some individual rail was overloaded. An OCZ Powerstream 520W worked fine on that board.

 

I see a number of 4-rail 650-700W PSUs pop up, from both Enermax and Fortron. I would really like to try some of those on all my "problematic" boards.

[siresword]

wow I have conflicting opinions now

 

from everything ive heard before, the ocz 520w was supposed to power almost everything you could throw at it (like optys with 7800gtx sli/x1900xtx's in crossfire with harddrives and whatnot)

 

but then Martin Cracauer posted :

Dual rail in practice is done because it is easier to provide high power cheap. In the example of the OCZ powerstream the maximum you can get on one rail is 520W total, which is not enough for high-end dual-everything systems.

 

so um um um um if I dont want sli but I do want an expert/opty/7900gtx, an ocz 520w wouldn't be a problem right? and then I hear that dual rails are a convenience, and *not* a necessity? Is that true ???? dkaSJDlkajsdlka

what about dual rails and overclocking ? if I bought an opty, I'd definitely want to see some kind of oc potential, where stability is a must.

anyway thanks for your replies and any that help with my confusion