I ordered some GS8208 and have a much more favorable view now.
Summary:
- Great 8 → 12 bit gamma correction
- No default patterns on the ones I received
- Power use is similar to the 12V WS2815
- Unusually slow on v2
- Backup data line
- High (8000Hz) PWM films well
Sourcing
I bought this GS8208 strip at 5m, 60/m, IP67. It was $33 ($.11 per pixel in IP67) with free shipping and arrived in 15 days. Here’s the Datasheet. I wired the backup signal path, labeled D2 on the strip, to GND as it says to.
This version/vendor does not have any default patterns built-in. They do, however, all flash white for a quick moment when powered on, which helps scare the out of you for a brief moment every time.
Gamma curve
It’s really good - much better than the WS2812 or WS2815. It’s perceptually linear across the full range of the global brightness scale. It’s kind of like having APA102 / SK9822 dynamic range but at the lower Neopixel data speeds. The low end has rich minor gradations: Driving at 1/255 of red, green, or blue creates a tiny amount of light, so you can mix for browns and very low whites, and fine tune the color temperature of whites.
Pixelblaze v2
On a v2, they are very sensitive to timing. The only output settings that will work are the “Buffered (x2 rate) WS2812 / Neopixel” setting at the slowest possible timing, “1.3us / 2.6us”. This limited output to about 5,500 pixels / sec for trivial patterns (18 FPS for 300 pixels).
Pixelblaze v3
On a v3, the default WS2812 driver with it’s only data speed of 800 Kbps 270/630ns worked great. Trivial patterns got 25,800 pixels / sec out the door (95 FPS for 300 pixels)
Power and voltage drop
Like the 12V WS2815 and most 12V LEDs I’ve used, the current usage for any one color being on is the same as when all three LEDs in a chip are on.
As a 12V strip, powering all 300 LEDs across 5 meters at full white did not result in noticeable discoloration or red shift. Vin was 12.0 V, and voltage at the end was 9.4 V.