Legit Reviews

Posted: **Fri Mar 24, 2006 9:50 am**

AeroCool has been around since 2001 and have started to develop a great name for themselves in the enthusiast and gaming community. Today we take a look at AeroCool's Zerodba 620W Power Supply Unit and see what their Zerodba technology is all about. If you are looking for a power supply that supports all ATI CrossFire and NVIDIA SLI video card solutions read on!

Besides the stability, another aspect of this PSU that really impresses me is the specifications. With a combined total of 30A supplied to the +12V rails, this PSU meets the 30A requirement for a high-end SLi PC according to this page over at SLI-Zone! If you are building an ATI CrossFire system you will soon find out that ATI doesn't mention 12V Amp requirements on their certified site and only list two brands of power supplies that are in their voluntary program. We contacted ATI and they informed Legit Reviews that their X1900 CrossFire solution needs at least a 550W power supply with a 38A 12V rail, which means the AeroCool 620W power supply will not meet the requirements for both ATI and NVIDIA power requirements...

Article Title: AeroCool 620W Zerodba Power Supply Review
Pricing Link: $119.99 @ ZipZoomFly

Posted: **Fri Mar 24, 2006 10:25 am**

I still have this PSU hooked up to one of the test systems and folding, so let me know if you have any questions!

Posted: **Fri Mar 24, 2006 10:37 am**

how cool is it? Meaning temp wise.

Posted: **Fri Mar 24, 2006 11:18 am**

Well, not sure exactly how to find that out for ya without a laser temp reader...

The fan switch on the back of the psu has 4 settings: auto, 50C, 60C & 70C... I would expect those settings to keep the PSU around those temps, but a good question, none-the-less.

Posted: **Mon Mar 27, 2006 12:06 pm**

Btw, just noticed the reviewer made a mistake on saying 38A on the +12V rails. The max output is 360W on +12V, so it’s actually only 30A.

Posted: **Mon Mar 27, 2006 12:17 pm**

It looks like it shows 38A on the label:

What math are you using to get the 30A number at 360W? Did you take 360w and divide it by 12v? That gives you 30A, but you did not take in to concideration that there is overvolt and over current protection. Both 12v rails are raited for up to 20a and 18a but the combined output cannot be more than 360w total

Posted: **Mon Mar 27, 2006 12:59 pm**

thats generaly a good sign as it means AeroCool over enginered the PSU.

Posted: **Mon Mar 27, 2006 2:34 pm**

is it actually 0db.... or does it make some noise... cause thats a bold statement!

Posted: **Mon Mar 27, 2006 3:10 pm**

Immortal wrote:is it actually 0db.... or does it make some noise... cause thats a bold statement!

I believe the standard the PSU companies use when taking dBA readings is to take the reading 'x' number of feet away from the unit. If I held my ear to the back of the case right next to the PSU, then Yes, I could hear a little noise. But if I just stand at the front of the case, I do not hear the PSU. Unfortunately I do not have access to a device that will give dBA readings to test this first-hand. I can only vouch that I can not hear it when sitting at my desk, but I could hear my old PSU from my desk.

So yes, it is a bold claim, but I don't think the claim is meant to be 100% silent when you put your ear to it, just that when you are so many feet away, it will be inaudible.

Posted: **Mon Mar 27, 2006 4:35 pm**

Zero_Cool wrote:It looks like it shows 38A on the label:

What math are you using to get the 30A number at 360W? Did you take 360w and divide it by 12v? That gives you 30A, but you did not take in to concideration that there is overvolt and over current protection. Both 12v rails are raited for up to 20a and 18a but the combined output cannot be more than 360w total

That is not entirely true. Both 12V rails have a max rating of 20A and 18A, but you cannot add them up together and say 12V rail has a 38A rating. Like you said, the combined output is 360W, which is 30A; therefore the 12V rating is 30A, not 38A like the reviewer stated.

Posted: **Mon Mar 27, 2006 5:16 pm**

Powermann and drexor69,

Thank you for noticing the typo in the article. It has been corrected and AeroCool contacted to figure out the correct combined Amps on the 12V rail. This is why it is so hard to buy a power supply today! I talked with AeroCool and they are going to talk to their EE about the rail and let me know what the real rating is.

Posted: **Tue Mar 28, 2006 8:14 am**

Thanks for noticing my error... I see now that the formula for determining the combined Amps on the 12V rails is Watts/Volts plus a few unknown variables for the overvolt & over current protection. Like Apop mentioned, we are asking AeroCool for the precise combined 12V rating... which we now expect to be very close to or exactly 30A. Sorry for the confusion in the article.

Posted: **Tue Mar 28, 2006 11:39 am**

I just got this response from AeroCool:

Power Supply design is a very special and complicated technology, PSU converts different voltage of input power into different regulated voltage output power. Different type/function of switching power supply has different requirement, even Intel's official released "ATX12V Power Supply Design Guide" just provides design suggestions and reference specifications for power supplies that comply only with ATX Specification motherboards and chassis.

According to Intel ATX12V power supply specification, there are different voltage of output power (+12V1DC, +12V2DC, +5VDC, +3.3VDC, -12VDC, +5VSB), each voltage has its Min., Max and Peak current output specified in manufacturer's PSU specification. There is also a Cross Loading Graph for typical power distribution for any rated wattage PSU which is the combined power for 12V, 5V and 3.3V for each PSU.

The combined power is defined as when different voltage of output current are combined together, the maximum power can achieve at the same time. For example, in our Zerodba 620W PSU, the max output current for +12V1 is 20A (12x20=240W), +12V2 is 18A (12x18=216W) but our combined output wattage for 12VDC is 360W (not 240+216=456W). The combined power for +3.3V and +5V is 280 W, but our combined wattage for +3.3V,+5V, +12V1 and +12V2 are 600W (not 360+280=640W), these figures are tested and specified by PSU manufacturer, some manufacturer may be too conservative or too aggressive. (some may use peak load)

In addition, there is a power limit set by UL1950/CSA950/EN60950/IEC 950 that "Under normal or overload conditions, no output shall continuously provide more than 240 VA under any conditions of load including output short circuit", this is why the maximum out current can not exceed 20A for each +12V output voltage power line. If you check with all the PSU on the market, you will know the max. output current are less than 40A (most of them are 38A). Our Zerodba 620W have max output of 38A which will meet SLI requirement.

So, from the above explanation this PSU should support the ATI cross-fire.

As you can see in the last paragraph AeroCool clearly states that their Zerodba power supply has 38A on the 12V rail.

Posted: **Tue Mar 28, 2006 7:31 pm**

Apoptosis wrote:I just got this response from AeroCool:

The combined power is defined as when different voltage of output current are combined together, the maximum power can achieve at the same time. For example, in our Zerodba 620W PSU, the max output current for +12V1 is 20A (12x20=240W), +12V2 is 18A (12x18=216W) but our combined output wattage for 12VDC is 360W (not 240+216=456W).

Our Zerodba 620W have max output of 38A which will meet SLI requirement.

So, from the above explanation this PSU should support the ATI cross-fire.
As you can see in the last paragraph AeroCool clearly states that their Zerodba power supply has 38A on the 12V rail.

Can you explain to me how AeroCool got 38A when they just clearly stated the combined output is 360W on the 12V? Are they measuring the max output without the combined output limitation? It just doesn't make any sense to me.

Posted: **Tue Mar 28, 2006 8:07 pm**

It doesn't make any sense to me either and I am waiting on their "math" used to come up with this figure. I am talking with their US office who is sending my messages to Taiwan to get the response from the designers. I should have another response around the same time as the first one and will post it up ASAP.

Posted: **Tue Mar 28, 2006 8:58 pm**

0 db is pretty impressive

Posted: **Fri Mar 31, 2006 10:52 pm**

Our readers were correct!

This is what I got from the R&D:

Zerodba PUS has +12V1 output for 20A and +12V2 for 18A, these two figures makes 38A. The combined load for +12V is 360W which is 30A. This is how you want to interpret it.

Posted: **Sun Apr 02, 2006 4:29 pm**

That's quite the PSU, thanks for the review Justin