🚀 go-pugleaf

In article <1993Jan24.014406.27423@mlb.semi.harris.com> sonny@trantor.harris-atd.com (Bob Davis) writes:
>In article <1993Jan23.231824.24755@rose.com> gyl.midroni@rose.com (gyl midroni) writes:
>	Even the fastest single drives can only spin the bytes under
>the drive's head at around 3 million bytes/sec.

That's about right. A few can break 4MB/s.

>	So, isn't a 5.33 million bytes/sec 16-bit slot on the ISA bus pretty
>much up to the task of delivering and retrieving data to and from a
>single hard drive that is only capable of spinning the data off or onto
>the platters at a 3 million bytes/sec rate?
> 
>	And isn't it expensive overkill to provide a 132 million bytes/sec
>truck (local bus) to haul 3 million bytes/sec freight ( a fast hard drive's
>maximum, spin-limited data transfer rate)?  Seems like that expensive local 

The "132MB/s" figure is just for marketing. The actual transfer rate is
limited by the speed of DRAMs. 20-30MB/s is realistic.

>	Perhaps in a heavy, multitasking environment there may be some
>merit to the ability of the local bus to more than double (98/44 = 2.2) the
>amount of time relative to an ISA bus that the memory address bus is freed up.

You hit the nail on the head: all this only matters if you're using an
OS that will take advantage of it (i.e. not MSDOS :-))

>system without heavy multitasking requirements. Certainly, I am not going
>to improve the prolonged data transfer rate onto or off the disk -- 
>3 million bytes/sec is as fast as data physically can be sucked up or spewed
>out.

Right. It goes without saying that a faster bus is not going to improve
single-drive performance.

>expensive, heavily promoted, and increasingly popular decisions regarding 
>hardware for the machine my wife keeps her recipes on :-).

:-)

Dan