And here are some temp droop figures. Same configuration, all running at about 2.45A. Clearly the Vero package flows and/or stands up to heat better, but not a large difference and not a fair comparison unless it was the CXA3590. We have more evidence that sanding and upgrading paste made no difference, maybe even decreased performance?
No significant difference in the cooling performance of the Rosewill vs the Alpine11. Fan power consumption was not taken into consideration for these figures, although if I increased fan speed any higher it would hurt efficiency overall, especially for the Rosewill.
These COB are running hard, 2.45A = 95-105W of dissipation. I was impressed by the performance of both COBs and both heatsinks.
Rosewill RCX-Z1
-----------------------
CXA3070 3K AB6 mounted on Rosewill RCX-Z1, stock
pulsed 410.3 lux/W
(5V fan = .72W) 391.3 lux/W
4.6% temp droop
Vero29 3K #1 - mounted on Rosewill RCX-Z1, stock
pulsed 420.2 lux/W
(5V fan = .72W) 411.3 lux/W
2.1% temp droop
Vero29 3K #2 - mounted on Rosewill RCX-Z1, sanded + PK3 paste
pulsed 425.2 lux/W
(5V fan = .72W) 415.2 lux/W
2.35% temp droop
Alpine 11
-------------
CXA3070 3K AB3 mounted on Alpine 11, sanded + PK3 paste
pulsed 423.4 lux/W
(7.5V fan = 1.02W) 407.5 lux/W
3.75% temp droop
CXA3070 3K AB7 mounted on Alpine 11, sanded + PK3 paste
pulsed 426.46 lux/W
(7.5V fan = 1.02W) 407.5 lux/W
4.45% temp droop
CXA3070 3K AB4 mounted on Alpine 11, stock
pulsed 428.17 lux/W
(7.5V fan = 1.02W) 414.4 lux/W
3.2% temp droop