I don't know if this helps, but here are a few facts and an educated guess...
Q-See's marketing info for the QT526-1 indicates that the DVR does D1 @ 30fps on all 16 channels. "The QT526 features real-time, broadcast-quality D1 video recording and playback which delivers large (704x480 pixels), clear images with 30 frames-per-second smooth motion." and "System captures video in real-time, broadcast-quality D1 704x480 pixel resolution at a rate of 30 frames per second (per camera)".
The QT526 looks like it's the TVT TD-2516HE.
The TD-2516HE marketing info says "Standard 4/8/16CH real time D1 recording."
I can confirm that the QT-528 will simultaneously record D1 @ 30fps on all 8 channels (240fps) (as well as a CIF sub-stream for each channel).
The QT526 and QT528 both seem to run the same firmware per Q-See's web site.
Taken together, I would think that the QT526-1 will simultaneously record D1 @ 30fps on all 16 channels (480fps). No guarantees, of course, until you try it!
-Bill