If not entirely then still partly in china. The real thing often uses more durable components and is subjective to more quality control.
Noticed one recently that sells bulbs and ballasts but 4 sets minimum. Cheap though, about $100 per set including a socket adapter allowing the use of a batwing or other reflector normally used for hps/mh. There are MANY diifent types if 315w bulbs with a large variety of specs and output, some much better than ones I see being sold at amazon, and I doubt everyone is using the best available, skewing the comparisson of the results.
Of course a 600watt hps yields more than a 315w, all marketing bullshit to claim it will outperform a 600w. The 315 does not have to yield 630 to be better though. It's a lot more comparable to a 400watt (specifically the 400w hpi-t plus, a regular mh), but probably a bit easier and more feasible to get a pound from a 315 than a 400. Either way, per watt it should outperform the 400 and 600w regardless. I've actually seen a grow with buds that look like they flowered under hps instead of the leafy stuff I mostly see.
If you get roughly the same from 3x315w as 2x1000 you're doing something very wrong as those 315s will not yield 5 pounds of nuggets.
Growing under high intensity light is not that easy. 600/1000w hps is no toy, requires proper climate control and water and nutrient regime... If you got a pound max with 600w magnetic, SE, then growing with a 315w may be for you. Real men, however, use HPS as nothing beats it, not the 315w (comparing bulb to bulb for a small space)and especially not a cob led... many combined running soft is a different story, and price tag... and indeed:
Though the things you can do with an electric toothbrush