I tried several tile sizes and ended up with 59 seconds being the fastest (that I tested).
- 128x128 = 1 min 20 sec
- 480x270 = 1 min 1 sec
- 240x540 = 59 sec (Winner winner chicken dinner)
- 512x512 = 1 min 6 sec
- 600x600 = 1 min 1 sec
- 650x650 = 1 min 7 sec
- 700x700 = 1 min 6 sec
If anyone else did this test with a GTX 1080 and got faster than 59 seconds, I’d love to know what those settings are. Thanks!