Floppy drive technology, is 20 years behind HD technology.
Ultimate capacity and speed
Floppy disk drive and floppy media manufacturers specify an unformatted capacity, which is, for example, 2.0 MB for a standard 3½-inch HD floppy. It is implied that this data capacity should not be exceeded since exceeding such limitations will most likely degrade the design margins of the floppy system and could result in performance problems such as inability to interchange or even loss of data.
The nominal formatted capacity printed on labels is "1.44 MB" which uses an incorrect definition of the megabyte that combines decimal (base 10) with binary (base 2) to yield 1.44×1000×1024 bytes (approximately 1.47 million bytes). This usage of the "Mega-" prefix is not compatible with the International System of Units prefixes. Using SI-compliant definitions, the capacity of a 3½-inch HD floppy is properly written as 1.47 MB (base 10) or 1.40 MiB (base 2).
User available data capacity is a function of the particular disk format used which in turn is determined by the FDD controller manufacturer and the settings applied to its controller. The differences between formats can result in user data capacities ranging from approximately 1300 KB up to 1760 KB (1.80 MB) on a "standard" 3½-inch High Density floppy (and even up to near 2 MB with utilities like 2MGUI). The highest capacity techniques require much tighter matching of drive head geometry between drives; this is not always possible and cannot be relied upon. The LS-240 drive supports a (rarely used) 32 MB capacity on standard 3½-inch HD floppies—it is, however, a write-once technique, and cannot be used in a read/write/read mode. All the data must be read off, changed as needed and rewritten to the disk. The format also requires an LS-240 drive to read.
Double-sided Extended-density (DSED) 3½″ floppy disks, introduced by Toshiba in 1987 and adopted by IBM on the PS/2 in 1994, operate at twice the data rate and have twice the capacity of DSHD 3½″ FDDs. The only serious attempt to speed up a 3½” floppy drive beyond 2x was the X10 accelerated floppy drive. It used a combination of RAM and 4x spindle speed to read a floppy in less than six seconds versus the more than one minute of a conventional drive.
3½-inch HD floppy drives typically have a maximum transfer rate of 1000 kilobits/second (minus overhead such as error correction and file handling). (For comparison, a 1x CD transfers at 1200 kilobits per second (maximum), and a 1x DVD transfers at approximately 11,000 kilobits per second.) While the floppy's data rate cannot be easily changed, overall performance can be improved by optimizing drive access times, shortening some BIOS introduced delays (especially on the IBM PC and compatible platforms), and by changing the sector:shift parameter of a disk, which is, roughly, the numbers of sectors that are skipped by the drive's head when moving to the next track. Because of overhead and these additional delays, the average sequential read speed is rather 30–70 KB/s than 125 KB/s.
This happens because sectors are not typically written exactly in a sequential manner but are scattered around the disk, which introduces yet another delay. Older machines and controllers may take advantage of these delays to cope with the data flow from the disk without having to actually stop.