We had a lot of troubles with Vantec’s last power supply, the Stealth.  We found an error in the production label, which quickly led to a change in all the labeling on all Stealth power supplies.  If anything, we were glad we could make a difference to change a product before it was too late.  Vantec took a lot of our comments to heart, and thus put out a second revision on the Stealth.

Click to Enlarge
Click to Enlarge

We were told that some of the changes in the power supply included tighter manufacturing specifications and an overall better performing final product.  Vantec also took the liberty of lowering the price of the unit a bit to avoid discouraging system builders.  With those new elements in mind, we set out to try one more time. 









combined theoretical

actual combined

advertised  total

Vantec Stealth 520W










Notice that the combined rail on the 520W Stealth is 260 watts.  Interestingly enough, +5.0V rail comes in at 260W.  This is unusually high, and as a result the +3.3V rail is unusually low.  We definitely would not recommend this power supply for AMD system builders, especially overclockers. (Intel system builders will have no problems with wattages).

The saving grace for Vantec comes in the features.  Later in this article we will explain why we are not crazy about the fan control switches, but the cable management, serial ATA connectors, and universal ATX adaptor are great additions. The 24 pin ATX cable will only show full usefulness on Intel server motherboards, but the 24pin to 20pin adaptor is included for standard desktop motherboards as well. The Stealth also comes with 9 standard molexes, which makes sense if this power supply is to target server markets.

By far, the best feature is the external AC plug.  Perhaps it is sort of a nostalgic addition for power supplies, but it definitely is an option that makes sense.  For example, plugging your speakers into the Stealth assures that they are off when your computer is off.  Thus, the speakers do not crackle or produce feedback when shutting down. We don't really recommend connecting a monitor to this outlet, particularly CRTs. You can really damage a CRT by pulling the power on it, so if your computer shuts down unexpectedly a lot, you will have a tough time keeping your CRT in good health.

The Stealth is not a cheap power supply.   Our 520W version costs about $120, which limits their ability to reach out to system builders with shallow pockets. Most of this cost is attributed to the aluminum construction, but other things such as the fan control also kick the price up.

ThermalTake PurePower 480W Vantec Ion 400W
Comments Locked


View All Comments

  • Anonymous User - Thursday, August 7, 2003 - link

    With each review unit, show a picture of the insides. Some of us can tell the design differences by looking at a picture.

    Claimed efficiency is a selling feature. An efficient unit doesn't need as much cooling air, and is easier on the electric bill.

    See if you can rent a load tester. Do a current ramp on the rails, to see what kind of dynamic response the units have. On +12V, this would happen when going from stop-grant, to 100% computing load. Power supplies overshoot when this happens.

    Your memory test is meaningless. A motherboard voltage regulator filters the rails, so this is unlikely to be a source of trouble with memory. Radiated emissions (E or M field) can influence circuitry, but you should use a spectrum analyser plus pickup coil to get some idea.

    Another emission test, is EMI coming out of the power supply via the power cord. For example, my Truepower interferes with Channel 4 on my TV set. This means the common mode EMI filter at the input to the PS is insufficient. Consult with an EMI expert on how to measure this.

    Overvoltage and overcurrent protection were not mentioned. Some units don't do it on all high output rails. Some don't do it at all. One unit had a circuit breaker on the back, which is a significant difference worth mentioning. The tolerance on some protection circuits is so sloppy, that the unit will burn before it trips.

    No review I've read so far has mentioned this clause in the ATX spec which is available from formfactors.org "The maximum short-circuit energy in any output shall not exceed 240 VA, per IEC 60950 requirements."
    For the high power models which violate this fire containment requirement, will my house insurance cover me if my PC lights the house on fire ?
    This requirement could be met by using separate outputs for +12 to motherboard and +12 to drives.
    Fire danger is a good reason not to use acrylic windows on a PC case.
  • Anonymous User - Wednesday, August 6, 2003 - link

    "Several months ago, we published our first power supply roundup."

    Do you mean this one from 42 months ago? :)


  • Anonymous User - Wednesday, August 6, 2003 - link

    pretty sweet review,
    the noise results were v interesting - does this mean that any computer without ECC memory is inherantly unstable?
  • Anonymous User - Wednesday, August 6, 2003 - link

    Hm... The memory test makes me wonder. Two things basically:

    1) How do you know the errors really are caused by the PSU? The figures suggest that it is, but have all other possible sources been ruled out? The numbers are low, and could be random variations for all I know.

    2) If memory content changes during 6 hours without read or write (and only the normal refresh), what does that mean for reliability on computers with up-times of months or even years? On the other hand, this could be the reason servers have ECC memory...
  • Anonymous User - Wednesday, August 6, 2003 - link

    Without wishing to be defamatory, Q-Tec units suck. In life you get what you pay for. These units have no safety circuits at all. They are of 'unlimited' design and the only control mechanism is when a component blows up. In so doing it may well take your mobo etc with it. Their top of the range unit provides less power on the 3.3v and 5v rails that most quality 300 watt units.
  • Anonymous User - Wednesday, August 6, 2003 - link

    You show the 'actual combined' on the huge EG651 Enermax at 200 watts. This is less than some 300 watt units. Why did you not highlight this? And why do Enermax put a 651 number on a 550 watt unit? Everyone else uses the number as the rated power figure.
  • Goi - Wednesday, August 6, 2003 - link

    I'd like to see reviews of Heroichi(HEC), aka Compucase, as well as Enlight, Topower and if possible Verudium PSUs. Also, the "ripple" measurements were only taken over a 30-60s duration, and only at full load. Other than the fact that what was measured isn't called "ripple" but actually the voltage fluctuation on the individual voltage rail, 30-60s sounds like a very short time window, and this should be measured both at idle and load conditions, since we all know that voltages tend to fluctuate when going from idle to load conditions and/or vice versa.
  • Anonymous User - Wednesday, August 6, 2003 - link

    How about Topower PSU's? I have seen a review elsewhere that says their 400W has similar performance to Enermax's (at a much lower price), but it was nowhere near as in-depth as your article.
  • Anonymous User - Tuesday, August 5, 2003 - link

    Antec 330 true power's performance on 12v is not enough for a P4 or high end video card? Funny, I have both and haven't had a problem........
  • Anonymous User - Tuesday, August 5, 2003 - link

    I personally thought the Antec True Power 330 was shining a little bit in this review. With 31.0 - 34.5 dBa noise, 26.5 - 33.8 C temp, on the lower end of memory errors, and a little tighter voltages than the average, it seems like it gives you the best combination of all categories. The only thing we're missing is some of the wattage testing. What do you guys think? And what about some of the other True Power product line - perhaps the 430 since 330 is at the lower end of PSU size that I would like to get for the power usage of any new computer (the True Control 550 is in a different product line than the True Power).

Log in

Don't have an account? Sign up now