This is a 300W fixture using 10 x Bridgelux EB Gen3 4000K 1.12m strips on flat bar aluminium.
Actual wattage is 0-295W, (up to 92% of driver capacity). The fixture is cool to the touch, measuring only 25°C after half an hour of testing.
The 320W HLG driver is 94% efficient, and rated for 7 years, while the EB3 strips are rated for 5 years. 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.
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.