Zalman ZM850-HP and ZM1000-HP

by Christoph Katzer on 6/27/2008 12:00 AM EST


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  • jamesu79 - Friday, June 12, 2009 - link

    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:">

    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,, 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.

  • gwolfman - Thursday, July 03, 2008 - link

    So if this is supposed to aid in cooling, where are the temp measurements? I'm quite disappointing not seeing any. I feel cheated since that's what's so unique about this power supply and you don't even test it. Boooo! Reply
  • BlandooV - Monday, June 30, 2008 - link

    What exactly does SLI and Crossfire guarantee you with a PSU? Also, I'm with MadAd...where do the heatpipes take the heat to that makes it more efficient than heatsinks alone? Reply
  • MadAd - Monday, June 30, 2008 - link

    Why? Just why?

    Heatpipes only move the heat from one place to another, its still got to be dumped out of the system some how.
  • schouwla - Saturday, June 28, 2008 - link

    In Japan the cheapest price is ¥29,498 for ZM850-HP Reply
  • Merman - Saturday, June 28, 2008 - link

    To quote your comment reply from the last PSU review:

    [quote]I find Ripple/Noise also very important but since nobody said a word I thought I could leave the graphics out and just add a comment. I always needed quite some time for the ripple graphs. I will add at least the comments again in the future and new models I get will have the ripple graphs again... alright? It's just there are not many people actually understanding what this topic is about and we need to still keep it accessible. No worries, I am working 7 years with power supplies and had several product managing positions in several companies. I know it's an important topic :)

    If you are not leaving out important information maybe its the editor??? The power supply reviews on this site have degraded to the point of not worth reading. :(
  • Kanchenjunga - Saturday, June 28, 2008 - link

    "It seems to be the same as the Antec Quattro which we tested last year. We recommended at that time to go for the smaller version with 850W because the 1000W unit didn't really bring many advantages with it. We will see later on in the tests if things are the same with these two units today. Even though we have 10 to 15 amps more on the 3.3V and 5V rails, the combined power of the 1000W unit is not too far away from the combined power of the 850W version. With the six 12V rails the same, there we have just roughly 200W more with the 1000W unit."

    Say what? It's not the same as the Antec Quatro which has only 72W of 12V power difference between the 850W and 1000W versions. And why do say the six 12V rails are the same when the label clearly says there is 240W difference?

    Also which of these two models in the review did you test for the DC output graphs and which of the six 12V rails does your 12V rail graph show and why are your reviews increasingly useless?

  • anonymous x - Friday, June 27, 2008 - link

    couldn't they make this giant thin smaller? My antec earthwatts 500 PSU, while delivering much less power, can actually fit in a micro-atx case without rubbing into my dvd drive. Reply
  • bob4432 - Friday, June 27, 2008 - link

    not the one about the tps reports, the one about the fact that ~85% of the people using computers don't need more than a 400W quality unit? WTF is up w/ these 1KW units? hell, even 650W or higher?

    i have a decent rig - e2160 @ 3GHz (swapping out to a e8400 soon as i need a bit more cpu for some 3d modeling appes), 3GB ddr2-667, 15k u320, 7.2k 7200.10, 3850 512MB gpu, gigabyte p35-ds3l, 3x80mm fans, a 92mm cpu fan and a few pci cards, and at idle this system pulls an amazing 95W, at full load using 2 instances of prime95 and gaming it maxes out at 185-190W according to my kill-a-watt. i am running it on a ~$10 antec EA 380 unit that works perfectly. if i had another pci-e plug i am sure i could run cf fine if i wanted to.

    my point - these 1KW units are kind of a joke for the majority of us but yet you reviewers just love them. why not review what the people need and actually make a review that will help people, the vast majority of people?
  • gwolfman - Thursday, July 03, 2008 - link

    You forgot to do you TPS reports? Did you get the memo? I'll be sure to get you another one. :) Reply
  • batpau19 - Friday, June 27, 2008 - link

    They (ridiculously overpowered PSUs) *are* a joke, and yet I am buying one.

    Acoustics, modularity, warranty, etc. are all there. When you look at lower powered versions or other models, you consistently lose at least one of these qualities.

    Point me in the direction of the 350 watt power supply that has a 3-5 year warranty, modular cabling, and silent operation and I'm sold.

    Problem is, the @5$hat PSU makers just don't do that sort of thing.
  • hechacker1 - Saturday, June 28, 2008 - link

    I agree. Even anandtech has used a kill-a-watt to determine actual load wattage.

    I can think of a couple things:
    1. People recommend exaggerated PSU's because cheap PSU don't actually live up to their marketing. Illegal, but how can you sue somebody for poor efficiency?
    2. Maybe peak load can't be accurately determined from the PSU use of power. I can imagine a loaded system that might need 1000w only for a short second, before dropping to something more manageable.

    I do wish that Anandtech would investigate the issue. I personally bought an expensive Enermax PSU a long time ago, 400w, and it seems to handle all the latest hardware without any problem. But the reason I bought it was precisely because it was highly efficient and actually delivered it's rated wattage.
  • mindless1 - Saturday, June 28, 2008 - link

    yet you don't need those things at all.

    If buying a lower wattage PSU it often has fewer leads so you don't have many if any to get rid of by modularly unplugging them.

    If it doesn't cost 4X as much, it's easy to overlook it not having a 3-5 year warranty.

    Silent operation is not a good thing by itself. Operation in response to temperature is a good thing. If you don't have good case cooling it shouldn't be silent. If you do, many PSU are easily ran close enough to silent (close enough it is something else you hear rather than a PSU pointed to the back of the system). However, all else equal you do still have a valid point in that if a unit is engineered capable of a higher load that means higher thermal load as well, meaning lower operating temp thresholds at an even lower system load than it's spec'd for.

    Perhaps more to the point, in response to what the prior person wrote about reviewing PSU more suitable for 85% of the users, you don't really need reviews for that. You can randomly pick one of several name brand PSU in the $40 range on sale or with a rebate and do fine for that sub-200W peak consuming system. No need to be really picky about one then so long as you don't get one with an exceptionally loud or short lived fan. Just don't try to cut wattage too much, that $40 range will get a 500W PSU and that affords more margin even if overrated than a same quality tier 350W would.
  • bob4432 - Saturday, June 28, 2008 - link

    guess the closest you are going to get is the antec ea series, but not modular. imho, for the price i would put up w/ the cables, but again, that is me. Reply
  • ahodge - Friday, June 27, 2008 - link">

    This one has been around for a long time too.
    I'm actually quite surprised that anandtech would mess up like this in an article. It's the first time I've noticed such a silly mistake like this. Usually you guys seem to really do your research. Oh well.
  • bob4432 - Friday, June 27, 2008 - link

    makes me wonder if they are doing these reviews just to get extra product and advertisers $$$ or us? sadly, i am kind of leaning further one way as not many need a 1KW unit.... Reply
  • zagood - Friday, June 27, 2008 - link

    "...and now we have the first and only power supplies with heatpipe cooling."

    Zalman ZM750-HP
    Zalman ZM600-HP
    Zalman ZM500-HP
    Thermaltake PurePower 350W Fanless Heatpipe

    Not the first, and not the only.
  • Turas - Friday, June 27, 2008 - link

    I mostly ike for how queit it is. I think they said at 500W it is only 17db. that is nice. If you look at a lot o the 5-600W power supplies they make a lot more noice as you get into the 400 + range. So even though the power is not needed it allows you to have a quiet machine since the power never really ramps up to the capacities. Reply
  • larson0699 - Friday, June 27, 2008 - link

    This is definitely for the guy splurging on those 2 or 3 GTX280's.

    But most of the systems I build use less than 200W at load.
    At 25% load any PSU bites on efficiency.

    I like Zalman's concept, though. Just wish they'd cater to the majority.
  • Turas - Friday, June 27, 2008 - link

    I too am wondering if maybe you had a faulty switch or something. silentpcreview also did a review of the unit and in their testing they did notice a slight difference to the better with the sounds turned on. They focus mostly on the acoustic side of things and even have sound recordings.

    I am glad to see to great reviews though from different sites. I think I am going to order one up now.
  • czarchazm - Friday, June 27, 2008 - link

    Maybe the "noise suppressor" feature wasn't working correctly. Is there any way for you to query Zalman about it? Seems like a neat feature to include if it worked. Reply
  • JonnyDough - Sunday, June 29, 2008 - link

    Maybe the label was just upside down? Can we test this theory somehow like maybe try the Rubik's Cube trick to see if it helps? :-) Reply

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