[Coco] hard disk performance

[Chuck Youse]

On Sat, 2008-09-27 at 05:43 -0400, Robert Gault wrote:
> Chuck Youse wrote:
> > I consistently get 24-25 seconds on my 80GB Seagate and 27-28 seconds on
> > my 1.2GB ST31270A, which yields approx 42K/sec and 38K/sec,
> > respectively.
> > 
> 
> I've looked up the specs on the Internet for the ST31270A and ST296N and 
> found the following for 512 byte sectors. My ST296N is formatted for 256 
> byte sectors and I don't know what effect that might have if any on speed.
> 
> ST31270A
> Data transfer rate   11.000 MB/S int
>                       16.600 MB/S ext PIO4
> ST296N
> Data transfer rate    1.250 MB/S int
>                        1.500 MB/S ext ASYNC
> 
> With the above as the limitations of the hard drives, the limiting 
> factor would appear to be the slow Coco clock speed and/or the driver code.
> It also "explains" the test result ratios of ~40K/sec for the AT31270A 
> vs ~12K/sec for the ST296N. The 31270A should be faster by ~10x but the 
> drivers are using 6809 sta vs 6309 tfm with a nod to the faster tfm opcode.

I see many flaws in your logic here but I lack the energy to address
them.  Typical Gault though, pontificating out your ass.

I wasn't really looking to do serious benchmarking here, anyway, I was
just looking to get some rough numbers.  I'm satisfied that my design
and its driver can deliver acceptable performance.

C.