I spent some time yesterday hooking up various Plextor IDE drives via an external IDE to USB plug adapter (the type without casing).
I was amazed that plextools would notice and access the drives including all the goodie-features. I then tried the 712A in operation, and here the trouble started!
Here is what I tried to do using Nero(220.127.116.11): I tried to write at 12x, but the burn failed 6% into the track. I tried again (this time at the rear usb2), and it failed again at about 8%. Both times the drive light went green and nero's progress indication simply halted, time kept counting, no error message occured till my patience run out. One burn failed at 6%, one at 13%. I then did successfully write a DVD+RW @ 4x. I then hooked up the 755 for a dvd+rw at 8x, which burned ok too. Then I created my third coaster by trying an MCC004 at 12x on the 755. That was the price for knowing that it wasn't a particular problem of the 712.
Then I decided that I had enough coasters on my hand and figured, that I should move my coaster production machinery away from the big PC to my notebook, where it shall be used anyway. From backups, I also know that the USB adapter works faster with the Intel chipset in my notebook than with the Via chipset in the desktop. At first, I checked the write transmission speed using Plextools and the 712A via usb2. Should have done that earlier, cause it reaches only 10.5x. Also, there is a downward spike once 8x is surpassed. These spikes seem to occur every time, once an even write speed is surpassed (8, 10, 12, 14 on the 755), probably PR kicking in.
Then I tried writing an MCC004 @ 6x using the 712A via USB, using Nero. It worked. Then I tried the same setting for 8x. Strangely, the drive wrote only at 6x CLV, whereas even the log stated that 8x is selected. I had PR on, and I have not yet tried it off.
So, aside from passing this information on, I have some unsolved riddles here.
What causes the burn to die above a certain speed? (i.e. AS, BP, PR) And why can't I burn at 8x, even though I seleced it? Wild guess: only Intel USB tells transmission rate to nero, and nero puts a halt to the kamikazi burn speed? (I am somewhat tempted to select 12x and see, if that only gets done at 6x as well)
Any informed oppinions on what I am doing or should be doing? I just ordered 100 more mcc004, cause I am about to run out of "soon to be coasters".