This is what I found.
(Also, Hi there! First time poster, don't want to go too far into introductions, because I'm posting this on multiple forums - I see a lot of Newbies asking this question in reference to their first build, and want to provide tested answers to their most-asked questions.)
So I spend a lot of time daydreaming about how to best upgrade my PC. I run a basic gaming PC, the parts that matter:
Intel Core i5-7600K
AMD R9 390 (with the intention to get a second)
So I need a little bit of juice to run the computer. Since I moved to the R9 390 I've hit serious bottlenecks.
I decided to do some research, and see which 850w PSU to use...
I also found TONS of discussions about whether to buy expensive name-brand PSU's versus buying one from companies no one has ever heard of - there were many "PC Gurus" going against getting a cheap PSU, for all the best reasons: "Don't want to risk a couple-hundred to a couple-thousand dollars by plugging it all into something that could short or catch fire..." but I didn't see anyone who said "Look, I've tried this, it's a bad idea."
So, spoiler - I've tried this, and it's a bad idea.
I purchased an 875W PSU from a company that calls itself KDM Power. They're supposedly based out of Houston, TX (my current city). I bought the PSU for $49.00, and picked it up at their "location" (a dirty warehouse in a strip-mall).
The packaging was simple, same cardboard box that everyone uses and the same anti-static baggie that most components come in.
The PSU itself is a bit of a mystery. No FCC Tag (which isn't a huge thing, it just means the piece wasn't tested with a case and motherboard) - but also no UL... no 80+. These are obvious warning signs that you've just purchased a $40.00 Lighter imported from China, but I figured what the hell... why not?
It came with all the right cables - nothing modular, unfortunately, so there was a mess of cabling inside my mid-tower by the time I'd gotten it all replaced. I hit it with a few quick zip-ties and closed her back up.
Power on - Nothing
Power on again - Faint Blue Flickers in the PSU LED
(Now, we'll slow down for a second here, to discuss my qualifications...
I fixed my first computer [a 98' E-Machine] in 1999. Figured out how to fix the drives so two weren't trying to be the Master, and I felt like a techno-god. Since then, I've built all of my PC's from scratch, and I've never [knocks on wood] burned anything up. I've made a few disc readers get locked in and shatter the disc while spinning in the bay, but who's NOT done that... right?
So I know how to set up and repair a computer. I held an active A+ for almost ten years before they made it into a renewal scam.
Back to where it got interesting.)
I double-checked all my cabling, made sure I had good contact with the 12V cable, and pressed the Power on once more.
This time, I got about three seconds of power from the PSU, and started feeling faint. Was the PSU actually about to start working?
And then it shut off again.
So in my mind, if I continue pushing the button, I'll get more power every time until it's producing power on its own and I can unplug it and never pay for electricity again. I hit the button approximately five more times, and it appeared as though my logic would bear out...
Until I smelled smoke.
The first spark thrown by the PSU was scary, but only mildly damaging. After the second and third I unplugged and segregated.
So, If I hadn't opened the case to check the cabling, my computer would have worked like a charm... until it became a bonfire.
To get to other important things, after sending a tersely worded email to my contact at KDM, I pulled out the good-ol' multimeter to determine how many watts I was actually getting.
The piece of garbage, this "875W" paperweight was trying to feed my components with 350W!
You get the idea.
So, for all you new guys who think you're smarter than us dungeon trolls, I wanted to ensure you could find at least one reference to a guy who purchased the same parts you're thinking "might work out" because you're so lucky, don't do it.
Save another bit to your budget from a couple more weeks' pay and get the component with the name brand, that's been tested, and is tied to a company that will go out of business if it sets your house on fire.
My PC (and slightly less importantly, me) survived. Yours may not.
(This post may be seen as completely unnecessary, but I think that since there's a lot of disinformation and people still asking questions, that it would be much better to flood this into some different forums and possibly save a [computer's] life)