Look guys, the original System 1.0 CD had less memory than System 2.0, did you forget about this? The DUO had the system 2.0 integrated into the console. The system 2.0 had more memory so it makes perfect sense that the newer system 2.0 included a 2x CD drive than the system 1.0's 1x CD.
In fact if you look into the CD window of the DUO while it's playing a game the speed of the CD is faster than the original TG16CD. You can see the CD labels spin faster.
Again 256k thing has nothing to do with not requiring a 2x CD drive. The games took decades to load on the orginial system 1.0 card, but according to your logic since it only has a little amount of RAM you didn't need a faster drive. According to your logic the game should be able to load in 2 seconds at 150kb/s...
A little snippy, aren't we?
System 1.0 wasn't released in the US afaik, we got System 2.0 and then System 3.0 in the Duo. And everyone knows that the original unit had less memory, hence the massive hype when the 3.0 system was being primed for release stateside.
Don't forget about seek time by the way...I have no solid specs or information on the laser seek time but it's obvious that the Duo's head moved faster, since it was a later model CDROM and technology had certainly improved by then (you can hear the thing move slowly on the original CDROM unit but it was quite fast on the Duo, and I'm sure that this too contributes to the perceived speedup). I never noticed games in the Duo spinning faster than the regular CDROM, but I did notice the obvious fact that discs spin faster or slower depending on where the head was. I don't remember games loading any faster or slower on either setup, frankly...the system always loaded pretty fast for 64k and 256k games. I'll run some tests myself once I get my setup working. It may be a 2x drive in the Duo (unlikely) and it may not be (more likely), we shall see, but my original point, which you were very quick to dismiss, is still valid...the Duo drive has a quicker spinup than the original CDROM unit NEC used and that contributes to the perceived difference in speed that some people have.
Incorrect information does often get passed around (anyone remember the "betting the powerup items" in half of the Internet sites' description of Ninja Spirit? or half of everyone calling it "Martial Champions" instead of its real name, "Martial Champion"?) but I'm pretty sure that after all these years, what's known is known...