
Full disc speed?
Any reason why you didn't test doing a full-disc DVD write? It's very rare I write a DVD that isn't going to be pretty much full - it would be nice to know whether the Pioneer's claimed performance means anything useful.
The current maximum write speed on a DVD±R is 16x, so Pioneer’s 20x drive has to be doing something special. Using 16x media, you should be able to see up to 25 per cent extra read and write speed. When recordable CD was introduced, it moved quickly from single-speed to 54x and beyond, but recordable DVDs haven’t accelerated …
Given that Pioneer gave claim to a heightened transfer speed once you got further to the edge of the disc, why did you not test this??
I can practically count on the fingers of one hand the amount of times I've put less than 4gig onto a DVD, so for me, testing 1gig is a bit odd....
The article is misleading. A 1xDVD spins just three times faster than a 1xCD. The higher data density of DVDs accounts for the factor of ten figure quoted.
So, a 16xDVD spins at the same speed as a 48xCD. Pushing out to 20xDVD is much like the CD people pushing out to 60x. The limiting factor is the physical strength of the media. The faster you spin, the bigger the chance that the whole disc will just fly apart. Polycarbonate shards are not nice; are you feeling lucky! Pioneer's proprietary technology to spin faster could be stronger discs or better public liability lawyers. I'll take the safety clothing either way.
As others have noted, this article is a little misleading.
Firstly the limit in speed is due to the physical limits of the spinning discs; it's not going to be any different to CD given the manufacturing processes, materials and dimensions are near identical. As James says, a 16x DVD = 48x CD (in terms of spindle speed) and a 20x DVD = 60x CD - nowhere near the claimed 180x which would be impossible with standard discs.
Secondly, and far more importantly, less than 25% of the disc was written to - Pioneer even commented on this result and yet you failed to re-test with 4GB or so to fill the disc.
The result of this is that you cannot form a proper conclusion until proper empirical testing has been carried out.
El Reg normally have such consistently good reviews and news, I feel somewhat let-down in this instance - perhaps you can (and should) re-test with 4GB of data to the disc?
Far more important than speed is the number of errors that are on disc after writing. Error concealing mechanisms do a good job of hiding most problems but once a disc decays or gets mucky, if the correction code is already working hard, then it's going to fail with a hard error.
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And shortly dropped back to 48. A CD disintegrating at 54x is like a hand grenade. It totally demolishes the drive and sometimes the machine. A 20x single read/write head speed on DVD should use similar rotational speeds. Hand-grenade in my case redux?
Disclaimer - I am old enough to have witnessed what happens when an idiot operator tries to pull the spindle on one of those ancient Vax 5MB drives with changeable disks without stopping the disk first. The holes in the door of the computer rooms and the shards sticking out of the wall on the side of the corridor were not a pretty sight...