better slow or fast read speeds? better CLV or CAV?

[calestyo]

Hey. This is mostly for CDs for which there is neither a AccurateRip or CTDB entry (or only one that differs)[0] The tests below were also made with EAC (yes I know that here is dBpoweramp ;-) ... but I'm quite sure the same observations/questions apply to dbp). I was again doing some tests with my Plextor PX-760A and the latest version of PlexTools, which includes a function to just measure the occurring C1, C2 and CU errors shown as a graph over the MSF of the CD. I tested it with one very rare CD, which I know that has very bad quality (no scratches, but, I guess the dye is chemically dead). Reading it with 4x CLV (in PlexTools) shows already very soon enormous amounts of C1 errors, little later C2 errors start rising (C1 errors already above 200/s)... and at around minute 30 or so CU errors start, soon afterwards also hitting the 200/s. EAC (with max 8x CLV) basically fails to rip that CD. Changing to 10-24 (this is in CAV at the PX760), the measurement in PlexTools look much better. Only 2 CUs in total (in contrast to some 100000 before) and C2 also starts at a much later point (e.g. minute 50 or so). Reading it in EAC (again with C2 enabled, but read speed 40x CAV) even succeeds... it does some re-reads at the very end of the disc... but apparently it believes to correctly read the data there. So basically the questions arise: 1) What's in principle better (in terms of better quality and/or error detection/recovery) for DAE? CLV or CAV? Most DAE programs seem to have the policy of slowing down when errors are found, so one (and also by common sense) would generally assume that slower speeds are better for extraction. 2) Given the above observation, is slower speed really better? Or should one read at max speeds? I mean the above observations could in principle mean both: - fast read speed = better for quality and/or error recovery/detection or - fast read speed is even worse in that C1/C2/CU errors aren't detected that good as at low speeds. Spoon once told me "modern drives are designed to rip at max speeds"... but that in turn doesn't mean that they'd perform better at max speeds than slow ones... and even dbp CD ripper reduces speed upon errors. Thanks. Chris. [0] Yes, I actually have quite a lot such rare CDs...

[Spoon]

Re: better slow or fast read speeds? better CLV or CAV?

It is not dBpoweramp which reduces the speed, it is the drive its self.