I have been burning and testing some media lately, and I have observed that my LiteOn SHW-1635S can be very touchy when doing Read Transfer benchmarks, expecially with DVD+R discs burned on my NEC ND-4551A drive.
When reading some Taiyo Yuden DVD+R discs burned in my NEC 4551, the LiteOn 1635 will slow down or even abort a Read Transfer benchmark at a point on the disc that seems to be the exact location of a re-linking point, i.e. a point where the burning drive stopped and re-started burning due to its Running OPC write strategy. No other drive that I have show any problem with these discs.
The LiteOn 1635 reports PIF spikes with maximum values of approx 5-7 at these re-linking points, but these spikes should in theory have no effect since they are located outside actual data blocks, and my Plextor and NEC drives don’t show these PIF spikes when scanning.
Comments, experiences and opinions are welcome!
Also the reading speed seems to depend on the media used; burning the exact same disc image to a Taiyo Yuden 8x certified T02 disc and to a 16x certified T03 disc produces two theoretically identical discs, except for MID, where the T02 disc is read at 12x and the T03 is read at 16x.
Is anyone else seeing this behaviour, and do you suppose it’s intentional?
Here are three Read Transfer benchmarks performed in the LiteOn 1635 of the same disc that shows the touchyness of the LiteOn.
The fourth image is a Quality Scan of the same disc - note that all PIF spikes above 2 are exactly at the re-linking point seen in the burn graph.
The fifth image is a Quality Scans of the same disc in my NEC 4551 drive which generally shows massive amounts of PIE and PIF but actually likes this disc.