Re: 2017-06-20-netbsd-raspi-earmv6hf.img

[Mark Millard <markmi%dsl-only.net@localhost>]

On 2017-Jun-24, at 3:47 PM, John Klos <john at @ziaspace.com> wrote:
> 
>> Not the best of examples:
>> 
>> 25 * 1024*1024 = 26214400
>> 
>> 26222722
>> vs.
>> 26214400
>> 
>> could well be in the noise for the time accuracy
>> or how exact the clock rate is vs. nominal.
>> 
>> (I'm not saying that you are wrong, just that the
>> example is not clearly faster than a nominal 25 MB/s.)
> 
> True. But considering there's overhead, and if the clock really is set to 50 MHz (sc->sc.sc_clkbase = 50000), then this should be showing a number greater than the maximum possible at that clock rate. I don't have any faster cards than a Samsung EVO +.

Well for a 32GiByte EVO+ on a macOS machine via dd:

8388608000 bytes transferred in 100.740420 secs (83269536 bytes/sec)

83269536
vs.
26214400

(A clear difference.)

I used bs=4m like you did. I did not wait for
the full /dev/rdisk3 to complete and so it
is a partial transfer result.


===
Mark Millard
markmi at dsl-only.net