I just took a closer look between the GCC-4480B / 4520B.
GCC-4480B = MediaTek Chipset (MT1616E/MT1628E)
GCC-4520B = MediaTek Chipset (MT1616E/MT1628E)
-The MT1616E is for 16x DVD Reading.
-The MT1628E is for CD-R/RW operations.
(Original Mediatek specs could go at 52X)
They are both using the same 2MB memory from Hynix :
HY57V161610DTC-7 (7ns memory)
They are both using the same SST firmware chip :
SST39SF040 (4Mbit, Flashable)
GCC-4480B - Factory build stamp starting from January 2003.
GCC-4520B - Factory build stamp starting from February 2003.
This look very promising!!
Hmm, i wonder why they didn't just go to 52X in the first place.
(With only 1 month difference between the two models, look like a marketing thing..)
Go get that firmware !!