Question about fitness for purpose of a specific PSU

[Onus]

I am considering buying this InWin case: http://www.newegg.com/Product/Product.aspx?Item=N82E16811108428 for a build similar to the recent "$400 Spirit of Mini-ITX" build. I would like to know if the included PSU is fit for purpose, or should be replaced without tasting A/C. I believe it to be a "PowerMan," which is not inspiring from the few reviews of the brand I've found, but they weren't disasters either. The initial CPU will be a Pentium G860, and the video card will be a HD7750. This build should not stress a 300W PSU at all.
Google was not friendly. Does anyone have any direct experience with this unit, or any citations to a competent technical review of it?
I'm trying to keep up-front costs low, and buying a Seasonic TFX just for the efficiency would be penny wise and pound foolish. Thanks.

 

[Tabris DarkPeace]

300 Watts at 70.71...% efficiency is only: 212 Watts.
- Is the rating true or before AC to DC conversion?

Your video card alone can pull 55 watts at load can't it?
- Overclocked it may go to 110 watts, which is impossible without external power.

It might run OK for 9 to 18 months...

 

[Onus]

Efficiency doesn't work that way. The PSU (allegedly) can provide 300W of output; its efficiency determines what its A/C draw will be to provide it. If the PSU is 70% efficient at 100% load, it will be pulling almost 429W from the wall.
The similar build on which this is based uses a mere 150W PSU. An overclocked HD7750 should not pull over 75W (and this one likely won't be overclocked, as the build won't be for serious gaming).
Even if this one is only good for 60% of its label, it would still be enough. I'm more concerned that it could be sufficiently crappy to die without apparent cause, which is why I'm interested in direct experience with it.

 

[ko888]

An AMD Reference Design Radeon HD 7750 at its stock GPU clock of 800 MHz and memory clock of 1125 MHz draws 50.22 Watts during gaming.

If the GPU is overclocked to 850 MHz and memory clock to 1250 MHz the graphics card's power draw only increases to 52.98 Watts.

This is measured at the PCI-E x16 slot through the +3.3V and +12V power lines in the slot since that is the only way that the Radeon HD 7750 graphics card receives all of its power.

 

[Tabris DarkPeace]

Yeah, that is how it works on honestly marked PSU in Western Nations!
- On the rest they do stupid things like either (1) lie outright, or (2) measure input and don't rate output at all, or (3) god only knows what.

Worst case efficiency for a PSU is going to be (2^0.5)/2... if it's worse than that it's a fire hazard.
Worst case measure is input wattage.

When in doubt I quote worst case, as too many people skimp and buy untrust worthy PSU's.
If it goes to court, and does less than what I quoted above they'll be jailed, or executed, for starting a fire; and possibly killing someone.

PowerMan might be a rebadged Rosewill, in which case it may be quoted as above.

As for GPU, you are right, I usually use HD7770 OC figures as a buffer since PSUs get less efficient over time.

Those 'YumCha' PSUs usually die, sometimes starting a fire, within 2 years.

 

[Onus]

Please remain on topic. I am somewhat of a "PSU snob" myself, and know the dangers of cheap junk. Efficiency is defined as I described it. The question is, is this PSU inefficient but relatively solid otherwise (e.g. older FSP), or is it outright junk (e.g. Apevia). The few reviews of the brand I've found have been "okay;" no dangerous junk, but low efficiency. That is why I am hoping for responses from people who actually have one, know its innards, or can cite a competent technical review of it.

 

[Onus]

From another forum, from c.hegge:
"The In Win should be fine. I use the 300W In Win TFX in the BL series cases sometimes. I haven't as yet load tested one, but after a quick peek inside, I do think it should easily do the rated 300W in spec. It does use OST and Samxon GF caps, though, which could be an issue in a few years time. I guess you could replace it with the Seasonic then if need be, though. "

 

[ko888]

From another forum, from c.hegge:
"The In Win should be fine. I use the 300W In Win TFX in the BL series cases sometimes. I haven't as yet load tested one, but after a quick peek inside, I do think it should easily do the rated 300W in spec. It does use OST and Samxon GF caps, though, which could be an issue in a few years time. I guess you could replace it with the Seasonic then if need be, though. "

Were you able to find out the temperature rating of those OST and Samxon GF series caps? If they're only 85°C then they could become an issue.

 

[Onus]

The "GF" line is the one that doesn't like heat; I'm sure they are indeed only 85C. In this build I expect them not to be stressed. It appears that this PSU is safe to use, although replacing it could be a future option.