The BDX-S600U is the first portable drive from Sony with the ability to
write to both BD-R and BD-R DL media at 6x. At this speed, it took a little
more than 22 minutes to burn an entire 25GB BD-R disc. The drive also
performed fairly well when writing to BD-R DL media, burning a full 50GB
BD-R DL disc in about 44 minutes. The BDX-S600U wasn't as fast when writing
to BD-RE media. However, its performance was on par with the other Blu-ray
Disc writers I've tested.