Kenwood TrueX 52X
+ Hard drive
like transfer rates
- Relatively expensive
- Drive and discs get hot
The CD-ROM is often one of the last pieces taken into consideration when buying or building a system and that is not incredibly unreasonable. After all, it seems like most of the time, the only time the CD-ROM gets used is to install software. As such, it's not too surprising to see all kinds of 8X or even slower drives laying around.
While it is possible to get by with such a slow CD-ROM, prices on drives have dropped so drastically that it is just not necessary to do so. Whether you just want your programs to install faster, or you would rather not put yet another 600MB full game install on your hard drive, a faster CD-ROM never hurts.
Starting with 4X drives, CD-ROM speeds were constantly being ramped up. Initially, increases in speed were gained by simply spinning the disc faster, which was successful for speeds up to about 12X.
Then someone got smart and realized that CD's were read using a constant linear velocity method (CLV), which means that the disc was spinning slower while reading the outer edges. This realization brought a new method, constant angular velocity (CAV), to read CD's. This meant that the disc was always spinning at the same rotational rate, regardless of what portion of the disc was being read.
That leads to data that is actually passing by the reading head faster on the outer portions of the disc, and thus higher transfer rates on the outer part of the disc. A by product of using CAV technology is that the drive motor does not need to change speeds, so access times are improved.
By simply implementing CAV, those 12X drives immediately became 24X "max" drives where the inner part of the disc was actually read at 12X and the outer part at 24X. Further increases in rotational speed have led to today's 50X "max" drives.
Unfortunately, data is written to a CD starting at the inside and discs are rarely filled to capacity. Thus, the max speed rating was not particularly meaningful. Further, the rotational speed required for a 50X drive is over 10,000 RPM, leading to major noise issues - some of those drives sound like jet engines while they are spinning!
Zen Research decided there had to be a better way...