>FLOPPY DISK ACCESS: The ST's 3.5 Inch disk drives transfer data to or from the 520ST at 31K bytes per second (over one hundred times faster than the Commodore 64's 300 bytes per second). The ST has been measured to access the disk between 40% and 50% faster than the IBM PC/AT.
DD drive = 250Kbit data rate = theoretical 50,000 bits (6,250 bytes) per 200 ms (300 rpm). But this is physical bits on media giving us that maximum theoretical 1MB capacity of DD floppy. Now the actual stored data require some overhead, sector headers, preambles, gaps. Standard space utilization is around ~74% resulting in 720KB floppies and Absolute maximum speed of a DD floppy drive driven by PC compatible FDD controller at around 23KB/s.
>HARD DISK ACCESS: The ST DMA port is capable of moving up to 1.33 million bytes of data per second -- this is so fast that there are currently no hard disks available that will transfer data at that rate! No other computer has a comparable port.
That figure is from Atari own documentation stating 1.25MB/s. Its also wrong, but this time in the other direction. Actual real world Atari ST ACSI port DMA speed is... drum roll, please... 2MB/s, very impressive!
Extraordinary, Mr. Blair measured faster speed than physically possible :) And faster than IBM using same type of FDD controller chip https://en.wikipedia.org/wiki/Western_Digital_FD1771
DD drive = 250Kbit data rate = theoretical 50,000 bits (6,250 bytes) per 200 ms (300 rpm). But this is physical bits on media giving us that maximum theoretical 1MB capacity of DD floppy. Now the actual stored data require some overhead, sector headers, preambles, gaps. Standard space utilization is around ~74% resulting in 720KB floppies and Absolute maximum speed of a DD floppy drive driven by PC compatible FDD controller at around 23KB/s.
>HARD DISK ACCESS: The ST DMA port is capable of moving up to 1.33 million bytes of data per second -- this is so fast that there are currently no hard disks available that will transfer data at that rate! No other computer has a comparable port.
That figure is from Atari own documentation stating 1.25MB/s. Its also wrong, but this time in the other direction. Actual real world Atari ST ACSI port DMA speed is... drum roll, please... 2MB/s, very impressive!
https://forum.8bitchip.info/atari-hardware/atari-st(e)-dma-t...
For comparison build-in DMA speed of PC/XT 0.9 MB/s, PC/AT 1.6 MB/s. Bundled PC HDD maximum theoretical data rates PC/XT & PC/AT HDD ST-506 MFM 5 Mbit/s, ST-506 RLL 7.5 Mbit/s. Very expensive mostly high-end server/workstation PS/2 ESDI 10/15/20 Mbit/s.