Zalman ZM600-HP 600 W Power Supply

[Olle P]

Jur: Had you bothered to read a couple of more PSU reviews on this site you'd noticed that the lack of noise comments is a common "feature" for all reviews.
The reason is that since the testers don't have the equipment to do some objective sound analysis, that property is discarded from the test.

For an objective (as well as subjective) noise analysis I recommend SPCR.

Cheers
Olle

[Jur]

I infere that you have been working on this.

Originally Posted by Merman

Perceived noise is completely subjective without a good methodology. What's loud to one person is easily different to another.

As you, (as ISO) say, its very subjective. Thats the reason of encouraging you to fill that gap.
- You are suppose to be imparcial.
- You already deeply test hardware.
- We (ITs, enthusiast, makers by itself, etc) need that information. We really "do not mind too much" about the method (look at the SPCR web, they use 10-0, and for the purpouse, its enough), as long as you explain it, its credible and, the most important, use the same method for all tests. Even an easy one could fit. We don't need you to give us the last ever formula for noise test. We have none or little at the moment (I knew SPCR but they are missing so many hardware, as this Zalman, that their data is almost useless). The only thing we have is the PSU in our desk, expecting to be, as the manufacture says, for ex. 20db and being worst than others that say 30db, as you pointed with the ISOs) .

Originally Posted by Olle P

The reason is that since the testers don't have the equipment to do some objective sound analysis, that property is discarded from the test.

Well, I should guessed it, but I think (humblely) that the reason you don't have the equipment, is too much perfection (for the case). As I said, almost nobody starts with the best. We build our tools as we can, but something can be better than nothing. Laught at this idea if you want: a microphone x feet away from the psu from x different places at x different loads in the a box reading high, medium and low frecuencies. I know, lots of things missing. Just "one step at a time". Some or all of this readings could be taken at the same time you do other tests.
But for different testers in n places, the tests could be harder to standarize, so, following the premise "something is sometimes more than nothing", I'am sure you all can get or already have got some kind of equipment (maybe already used in other test) that could be use to get some kind of "valid objective measure".

Please, don't see this reply as something more than encouraging words.

Cheers
JM

[DavidFlorida]

I kind of agree with Jur, in the sense that a subjective opinion from someone we trust has value.

If Gabriel said, "This power supply seems loud for a 500W PSU", or "The XYZ800 is, in my opinion, quieter than any PSU we've tested", I could base a purchasing decision on his comments because I trust his opinion.

[Merman]

I can't speak for Gabriel but I do know this:

We won’t measure acoustic noise level. We may post comments about the noise level of a particular power supply under a particular scenario but as a regular user, with no scientific methodology (e.g. “this power supply was very quiet even when delivering its maximum power capacity”). Measuring acoustic noise is very complicated, especially when we have other items generating noise near the product being reviewed, like the load tester.
http://www.hardwaresecrets.com/article/522/6

He does comment when noise is extraordinary low or maybe because of the manufacturer's claims. This is from the Enermax PRO82+ 525 W Power Supply Review that claims to "having the world's most silent PSU fan control (and series) without sacrificing on heat or cheating even with sleeve bearing.”
http://www.hardwaresecrets.com/article/551/2

The fan used on this power supply is extremely quiet even when it was running at its full speed. In fact this was the quietest power supply we reviewed to date.
http://www.hardwaresecrets.com/article/551/8

Originally Posted by DavidFlorida

If Gabriel said, "This power supply seems loud for a 500W PSU", or "The XYZ800 is, in my opinion, quieter than any PSU we've tested", I could base a purchasing decision on his comments because I trust his opinion.

I suppose if the comment is "quieter than any PSU we've tested" this could be trusted. But if the comment is qualified how can one know if a subjective opinion is compable to your own without hearing the same PSU??? With so many people with different opinions many could be disappointed with a qualified quiet opinion. Even SPCR records their results so you can hear it for yourself.

[Cheetos]

Knowing Gabriel's way of reviewing hardware I imagine that he will only test noise levels if he has an acoustic chamber.

But how will he control the temperature during the tests ?

And how does this noise level, measured in an acoustic chamber, will represent the conditions of our PCs ?

My PSU even at load is covered by the case coolers, but if it's noise level were measured in an acoustic chamber I'm sure that the result won't be the same.

It's not so easy as it seems, and I'm not saying that measure noise levels is useles or that other sites are wrong.

[Gabriel Torres]

Originally Posted by Jur

I am really surprised. 11 pages of analysis of "gathering observable, empirical and measurable evidence" (wiki) and you miss the noise level perceived by a human being (db).
I know, I know... this is an electrical/electronical study.
But perceived noise is one of the most important features of a PSU (or any electromechanical hardware. who of us would not want an absolutly silence pc?) and one of the main reasons for the manufacturers to improve them (remember 5 years ago?, the headache noise of most pcs?). Thats the reason behind of zalman including a heatpipe, right?.
So, if you miss that very important point you/we cannot compare them wisely.

Just two cents... or not.

Hello,

We are looking forward to buy a noise meter to make our reviews even more complete in the future, i.e. to have mensurable data. I avoid adding information about noise because this would be a subjective analysis and thus an easy target for criticism. But, like Cheetos pointed out above, when the power supply presents a noise level out of the ordinary (for the good or for the bad) I always make my comments on that.

Thanks for your suggestion though.

Cheers,
Gabriel.

[Gabriel Torres]

Originally Posted by Jur

I infere that you have been working on this.

I am the one that wrote the review and all other comments were posted by users that visit our website. People like you.

Cheers,
Gabriel.

[Gabriel Torres]

The results from this review were updated today to reflect AC power and efficiency measured by our new precision power meter. The updated results did not affect our conclusions or recommendation about this power supply.