ZALMAN ZM850-HP 850W -- Best PSU to buy?

[bexx]

Ignore the capacity being a big number..

http://www.newegg.com/Product/Product.a ... 6817379007

As long as this is similar to 1000W version, which it looks to be, at $159 its hard to pass up IMO.

Unless your system is very low end but comparing 1000watt Zalman to 625watt Modu82 its not like you get much better efficiency with the Modu82 at anything but the lowest power draws. Plus Zalman is cheaper, no fan issues, and no buzz from PSU.

Any reason to believe the 850W and 1000W versions are different?

[MikeC]

No reason. Their acoustic behavior is almost identical. I've used them both.

[lodestar]

It has a couple of drawbacks. No on/off switch. And due to the heatpipe cooling it is at 21cm/8.25 inches somewhat longer than other PSUs. That said, the price is good, but I have the Enermax 625W MODU82+ which is $10 more from the same supplier. No issues with the fan or anything else, just an extremely quiet and reliable PSU. I would pick it over the Zalman every time.

[Kalts]

Ignore the capacity being a big number..

http://www.newegg.com/Product/Product.a ... 6817379007

As long as this is similar to 1000W version, which it looks to be, at $159 its hard to pass up IMO.

Unless your system is very low end but comparing 1000watt Zalman to 625watt Modu82 its not like you get much better efficiency with the Modu82 at anything but the lowest power draws. Plus Zalman is cheaper, no fan issues, and no buzz from PSU.

Any reason to believe the 850W and 1000W versions are different?

I cannot recommend the Zalman 850W PSU because it makes very annoying high frequency chirping/squeaking noise when load oscillates. I'm not alone, one fella with 1KW PSU has same problem as you can see here: viewtopic.php?t=50175
Also dig around and you'll see surprising amount of hits about the very same problem. Not Zalman specific, though.

[Kaleid]

I had that "high frequency chirping/squeaking noise" at least during two conditions with my former 850w unit which I have now replaced.
1. During heavy HDD activity
2. All graphic cards whined. Not when idle but when loading heavier websites with flash and similar plus in 3d-mode when the graphic cards heavily squealed.

[Kalts]

I had that "high frequency chirping/squeaking noise" at least during two conditions with my former 850w unit which I have now replaced.
1. During heavy HDD activity
2. All graphic cards whined. Not when idle but when loading heavier websites with flash and similar plus in 3d-mode when the graphic cards heavily squealed.

At least that means quiet exemplaries exist I see alot of talk about graphic card whine, but don't understand it fully. Is the whine caused by graphic card only i.e. whines whatever PSU one uses? Or is it caused by specific graphic card and PSU combination? Sure that some cards are more prone to whining, but I can't believe that one particular PSU makes all graphic cards whine no matter what? I tried with two different cards, old Radeon X600 Pro and now I have passive Asus EAH3650. The annoying chirping didn't change a bit and certainly came from PSU. What I'm probably trying to say is that graphics card didn't matter and PSU noise was function of CPU load

[Kaleid]

I tried four different graphiccards (x1900xt, hd3870 and two hd4850) and they all whined with the faulty 850w unit. Once it was replaced the graphic card that I'm using now, a Sapphire HD4850 Toxic stopped whining pretty much completely. Haven't tried the x1900xt and 3870 again but I assume that they would stop whining as well.

In another system with an Antec 430w Earthwatts I know the x1900xt does not whine.