Thanks, as an engineer I value a technical explanation.
When I set IMGBurn to burn at 1X, it never drops below 2X, so I'm assuming IMGBurn forces the burn at the minimum rated speed for the media even if you select it lower than that.
Last night, I tried a burn on a 4X Ridata BD-R at 4X (img burn says supported speeds are 2x, 4x, 6x, and 8x). The burn started off at 4X, but when I looked back a few minutes later, it was burning at 2X and stayed that way the rest of the burn. Does this mean IMGBurn was having difficulty burning at 4X and went lower automatically? I verified the disc after burning and all green.
Is it a good rule of thumb to always burn at half the max rated speed?