This is a 300W fixture using 10 x Bridgelux EB Gen3 4000K 1.12m strips on flat bar aluminium.
We can wire it in parallel on an HVG-320H-42A driver, (93.5% efficient, 5 year rated)
Or in series and parallel on an HLG-320H-C1400B driver (94% efficient, 7 year rated)
The fixture is cool to the touch, measuring around 25°C.
The fixture has a consistent PPFD, measuring above 400 PPFD over the entire fixture at a distance of 25cm. So it can also flower adequately in the gram per watt range.
For high flowering intensity levels, you need to run the fixture closer to the canopy, (eg. 10-15cm, yes, really), and use training, such as supercropping, to maintain a flat canopy. It requires a different growing style, to other lights. But the benefits are that you can cover a large area with practically any PPFD.
Tuned down to 250W, the fixture will achieve 200lm/W pre-driver (188lm/W post-driver), for 2.8uMol/J system efficacy. At full power, the fixture achieves 2.7uMol/J system efficacy.