Discussion in 'Reviews' started by W1zzard, Dec 11, 2007.
To read this review go to: http://www.techpowerup.com/reviews/Zalman/ZM1000-HP/
Man thats a nice psu.
I had the zalman HP600 in my old machine and it was great. Modular completely quiet and never missed a beat.
At first, I thought it was just heat pipe cooled. Thank God I saw and they put in a fan. Nice PSU and ranks right up there in the tops.
The official SLI list only specifies that the ZM-850 is compatible with dual GX2's. surely the next model up is also compatible?
I would like to bring the spotlight to various issues regarding this product and some of it's siblings (zm850-hp for instance). It suffers from a quite extreme variant of coil whining / squealing. Some sort of electrical high pitch noise that just drives you insane. I found a good video of it here: http://www.youtube.com/watch?v=mQa79pWC0OQ
This seems to happen with a lot of the newer graphics cards, especially Geforce 260/280/285/295 and Radeon 4850/4870X2 etc etc. It also produces the same noise when you scroll a web page or copy a file to your hard drive. In fact, any hard drive activity triggers the same sound, albeit at a lower intensity, but still very audible.
When I first got this power supply and noticed this I tried to get in contact with Zalmans support. They kept telling me that they had forwarded my messages to their supervisors who, during a period of 4 months, haven't e-mailed me back. Not even once. Even though i sent follow-up e-mails twice a week. Or they would tell me to send e-mails to this other set of addresses (support1,2,firstname.lastname@example.org), which never replied either. I did this 2 times a week for 4 months.
In other words, I was being completely ignored by their so called "support". They have been indefinitely postponing any type of resolution for this problem.
The issue gets worse when you realize that even if you RMA this product, since its a manufacturing fault; you would just end up with the exact same problem.
My honest recommendation to anyone thinking about buying this power supply would be to stay away. Or do very, very thorough research on if the rest of your PC components are compatible with this PSU in such a way that it doesn't generate squealing.
did you try another psu and the coil noise went away? afaik it is a function of gfx card+motherboard+psu
No, I have only been trying to reach their support for the last couple of months. But it is a known and confirmed manufacturing fault from Zalman. They said that they fixed this issue for the zm750-hp model. Although they probably didn't withdraw the afflicted ones, so they are probably still being sold as well. Guess you'll have to take a leap of faith with that one.
I wonder if Corsair HX1000 would be a good replacement
i've seen vga coil noise on almost every psu i ever used. please let us know if another psu fixed the problem
Its not the vga coils though, its the psu coils. The squealing clearly emanates from the psu. And it really is a lot louder than your average coil whine. It literally sounds like a dentist drill being run through a cat's skull, only played back at 10x speed and 10x higher pitch.
Alright, I'll post back when and if i get another psu.
nice PSU! very informative & in depth review W1zz
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