EVGA 450 B3 PSU Review

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EVGA's new B3 line succeeds the older B2 family. All units are fully modular and have 80 PLUS Bronze efficiency. The 450 B3 is the lowest-capacity model, and as you'll see, it struggled with our test suite.

EVGA 450 B3 PSU Review : Read more
 
Throwing higher current components at a problem isn't always the correct solution, especially when a 450W PSU is delivering somewhere north of 550W. The B3's components are clearly vastly sufficient to handle its rated load or even the 580W overload, which means the most likely reasons why a FET blew up are either a design flaw or manufacturing defect and the flaw/defect isn't necessarily in the FET or its immediately related circuitry.

In this case, it seems like EVGA/Superflower may have incorrectly set the OCP on the 12V rail. I hope they meant to set it to something more conservative like 40A instead of the 50+ it may have been at here.

As for the main fuse not blowing, that is normal: the fuse lives upstream from the APFC choke and most other filtering components while both the APFC and main switching transistors are connected to the APFC-boosted input hold-up capacitor. The transistor's lead blows up from the capacitor dumping its several joules of energy into the lead, the APFC chokes smooth out the current spike and the current seen by the fuse comes nowhere close to reaching its i2t rating. It is the capacitor's charge that blows up the transistor, not AC input current.
 
I strongly disagree. The main fuse has to blow when there is a short on the primary side, which clearly is the case here, else the PSU is a fire hazard if the automatic relay on the home's main electrical panel doesn't work as it should. The spark every time we connect the PSU to the mains means that high current passes through the circuit, however the fuse still remains intact. Another clue here is that our lab's relay on the electrical panel automatically dropped (saving the day), meaning that more than 15 Amps of current were drawn from this particular AC socket!! So clearly the PSU's fuse should have blown. Finally, I have seen a great number of blown PSUs so far and all have some common component failures: primary or APFC FETs, bridge rectifier(s), main fuse. In any case the main fuse has to go else the design has a serious flaw.

Some FETs might have increased Amps on papers, however in real life things can be different especially when the high RDS (on) values increase the operating temperatures. The part though in this PSU which I am not so sure about is the bridge rectifier, since it can only handle 8 Amps at 100C and usually I see more than 100C at the bridge. So if the bridge goes up to 115-120C its max current drops close to 5A according to its spec sheet so we only have 575W handling, which is much below the 700-720W that the PSU draws from the wall with 580W load.

The APFC choke isn't for filtering purposes, but mainly for boosting voltage, this is why it is also called boost inductor. More about how the APFC converter works and an explanation on both most popular types (DCM, CCM) can be found here: http://www.tomshardware.com/reviews/power-supplies-101,4193-10.html. I think it is pointless to explain APFC's operation here since there is an entire section about it. The bulk cap's charge didn't exactly blow the FET, the FET just couldn't handle the increased Amperage that the cap provided because of the high load. Also the bulk cap drew this load from the mains network and didn't make it out of thin air!

Finally please don't lose sight of the forest for the trees and confuse the readers on a subject that is clear. The fuse that protects the socket into which the PSU was connected dropped, meaning that more than 15 Amps passed through it! Given that this PSU's bridge can only handle up to 8 Amps normally its fuse should be less than 8A, however it survived not once, but both times that we tried it! This clearly shows a major flaw and on the same times proves that there is a short on the PSU's primary side, which draws LOTS of current! In any case the main fuse should open the circuit in order to protect the user and the equipment from damage or even fire. The main fuse not blowing is anything else but normal! I just have to point this out
 
$50 for a modular power supply seems like a great deal, even with merely Bronze efficiency. This is a good reminder not to gamble on a PSU that hasn't been reviewed by a site like Tom's Hardware.
 

Put a 1mH APFC choke in series with a short circuit and 350V, it'll limit current rise time seen from the input side to 350A/ms, so it does filter regardless of what its other purposes in the circuit is just like any inductor would.

I missed the paragraph about the breaker tripping. If you have RCDs or AFCI breakers, they could be tripping due to faults other than a short-circuit. If you have class-A relays, it could also be tripping faster than the fuse is able to blow.

Edit: missing a 0... 350V/1mH = 350A/ms.
 
But we are seriously troubled by its issue and EVGA's lack of a response when we probed for possible causes.
Click to expand...

That is deeply troubling, especially coming from a highly reputable hardware vendor like EVGA and who I have nothing but the highest respect for (I've been buying their GPUs solely since the GTX 275).

I sincerely hope EVGA isn't quick to get back because they are trying to find a root cause with Superflower and rule in or out a bad manufacturing batch that got past Superflower, or a bad design. I hope for EVGA it's the former.

 
@INVALIDERROR I will try this in a circuit simulation program I have, once I find some free time.

@ANDREWJACKSONZA If you mean about the blowing PSU in smokes, nope this is another PSU.

@10TACLE Once we have a response from EVGA we will post it of course. To be frank I waited for a second sample from the time I notified about this problem, however I was not offered one. Also from the start EVGA didn't send any B3 samples and this is why I had to buy them on my own (given the popularity of this line), in order to check them out. With the first chance I will also buy affordable PSUs from other vendors, which usually aren't offered as review samples, in order to evaluate them.

I would buy another 450 B3 but it is out of stock every where I searched in Europe. If I manage to find one I will try the same test again of course. Nonetheless I faced problems with other B3 models as well, which I will mention in the next B3 review.
 
I don't find it all that surprising that they didn't shoot for a higher efficiency rating. EVGA's primary market is the US (correct me if I'm wrong), and Silver is basically a non-entity here. Bronze is the volume segment, so having a strong contender there is a necessity, and pushing it to Gold would add to an already-crowded segment of their product stack.
 
As nasty as that blow-up might be, if used in a machine that doesn't need more than 450W, is it really a problem? Arguably, someone who tries to run a 600W PC using a 450W PSU deserves what he gets. For low-end systems, this looks like a perfectly viable choice.
 

If what you wanted to simulate is the current rise rate or filtering, no need to: Vinductor = L * di/dt. If the voltage is relatively constant for the period of interest, di/dt = V/L and I just realized that there is a missing 0 in my previous post, should have been 350A/ms for 350V and 1mH.

Personally, I've seen breakers trip faster than fuses can blow quite a few times. On one particularly careless day, I managed to short a PSU to chassis tripping the breaker three times before its 6A input fuse died. Slow-blow fuses don't necessarily die on the first short when there is a faster device upstream.
 


Or OEM replacements for that matter. I always recommend to people upgrading their OEM PC's crappy PSU. Recent case in point: a friend was in a bind with a dead PC used for his business and had no time to diagnose and/or build another. He rushed out to Best Buy and found an HP OMEN "gaming" PC on sale with a GTX 1070 Founder's Edition (the same thing Nvidia sells direct from their website).

I went over there after he got back and the first thing I did was open the case and look at the PSU: as expected it was a non-branded 500W PSU with terrible max sustained wattage output specs with a low temp threshold. Yeah that's not happening. After he closed up we went to Fry's and picked up an EVGA 550W G2. The 550W G3 was $20 more which is the only reason we got the G2. Thank God we did apparently.

 


That's not really the situation where overpower protection is needed most of the time, though. If there is a shortage with a yellow wire with a low enough impedance, short-circuit protection will fail to detect it, and then as current rises it's up to OPP to save the day.

Or if companies were smart they'd still be doing multiple 12V rails.
 

For outputs under 40A, you should be fine with a single rail and working OCP/OPP set to the correct value: even #24 wires can pass safely 40A long enough to trip a working OCP. Not that having multiple output rails would have made any difference in the case of a primary-side catastrophic failure anyway.

Also, having multiple rails does you very little good if their current limits are well beyond what they should have been as it appears to be the case here. A functional 40A OCP limit on the 12V rail here would have prevented the PSU from delivering more than 480W instead of allowing it to self-destruct at 580W.
 
It seems strange to me that the fact that the PSU exploded didn't seem to play into the performance score.

IMHO, if a PSU represents a potential fire hazard, it seems fitting that it should not receive a better score than a PSU that doesn't. There should be a couple of other "deal-breaker" grade problems that, as I see it, should play into the overall performance rating so the product is not incorrectly portrayed on the comparison charts that you use in the Best PSU.

Examples include:
  • ■any form of catastrophic failure,
    ■improperly designed protection mechanisms (This is not to be confused with fewer parts. I'm exclusively referring to a protection mechanism that doesn't do it's job properly, as in this review.),
    ■failing to meet load regulation requirements in any test (not as detrimental as other items in this list, but can cause caps in other parts of the system to fail prematurely),
    ■improper grounding,
    ■any other potential safety risk.
 
I would love to see a review abtout the EVGA 750 G3 - is it less noisy and has a better hold up time then the 850 G3? Do you have plans on doing a review on the 750 G3?
 
If this failure had happened at 450W, or even 500W, I'd probably consider it a dealbreaker as well. At 580W though, although it is definitely worth noting, that's so far beyond what a 450W PSU should be able to handle that I'm much less concerned; short-circuit protection is shown as working. I really hope EVGA is sincerely looking into the matter though, not simply ignoring it.
 

EVERY PSU or device handling high power is a potential fire hazard and not immune to the occasional material or manufacturing defect that could cause an otherwise good design to fail catastrophically.

With a sample size of one, it is impossible to tell whether this is an isolated defect, a rampant QA problem from a parts supplier or an outright design flaw. The only thing that can be said is that one sample failed. While this may not inspire confidence, it isn't sufficient to definitively condemn the product.
 


They should be the same platform, so I expect them to be very similar. Internals comparison:

http://www.jonnyguru.com/modules.php?name=NDReviews&op=Story5&reid=500
http://www.tomshardware.com/reviews/evga-supernova-850-g3-psu,4930-3.html

Also, you can see noise ratings at http://cybenetics.com though it seems they don't have the 750 G3 so nevermind.
 


About noise, checking EVGA site I saw that the fan curve in the 750G3 is much more relaxed then the 850G3 (and 1000G3), so I was wondering how that would translate in the noise output.

But considering the 750 G3 has the same internals and less power then the 850 G3, can that improve the hold up time? I read the 850P2 and 750P2 review here on tomshardware, and the 750 P2 has a much better hold up time. Could that also happen with the G3 series?
 

The input capacitor dictates how much energy it holds and how long it takes the PSU to cut off under load. If you measure hold-up under full load as is usually the case, you can expect the 750W PSU to last ~12% longer than an otherwise identical 850W PSU simply because it is outputting 12% less power and draining its input capacitor 12% slower. If you compare both PSUs while under a 400W load however, you can expect nearly identical results.
 
Actually I was thinking about getting the 850P2, but I gave up because of the hold up time test ... I also liked the 850 G3 review, very clean power, but then the noisy fan pushed me away from it. My last hope was the 750G3 being a middle ground betwing both.

What I really want is a 750-850w PSU that delivers clean power, no coil wine, and zero to very low noise at up to 500w usage at normal room temperature.

I can buy the 750G3 or the 750P2, their prices are very close (or even the 850P2 paying a bit more). What would you pick? It seens that the G3 has clener power with tighter regulations, is that right? Any advantages of having the P2 thicker 16 AWG cables?
 


You should buy one of the Aerocool P7 power supplies. Here is a review of the 650W https://www.techpowerup.com/reviews/Aerocool/ACP-650FP7/ - it doesn't get much quieter than that. It's an incredible PSU.
 
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