Re: AMD Ryzen and NetBSD?

[Patrick Welche <prlw1%cam.ac.uk@localhost>]

On Fri, Jun 30, 2017 at 12:00:45PM -0400, Thor Lancelot Simon wrote:
> On Fri, Jun 30, 2017 at 04:55:40PM +0100, Patrick Welche wrote:
> > On Fri, Jun 30, 2017 at 03:41:39PM +0000, maya%netbsd.org@localhost wrote:
> > > On Fri, Jun 30, 2017 at 09:25:19AM +0100, Patrick Welche wrote:
> > > > I'm happily running -current on a Ryzen 7 1700 / Asus PRIME X370-PRO.
> > > > I wonder about its i/o though: I remember dd'ing zeros over old disks, and
> > > > thought "this is slow", so I dd'd over 3 disks at once, with no change
> > > > in individual "progress" bit rate, i.e. 3 times the bandwidth...
> > > 
> > > Are you specifying block size? dd is terribly slow without it.
> > 
> > I was using 64k - essentially the example in the "progress" man page.
> 
> Latency.  You want a double-buffered pipeline.

I shoved a rather newer ST2000DM001-1CH164 in, which according to its
marketing bumpf can manage "Max SustainableTransfer Rate 210MB/s"
and not so bad:

# dd if=/dev/zero ibs=64k | progress -l 976751887b dd of=/dev/rdk15 obs=64
k
 99% |********************************** |   465 GiB  116.74 MiB/s    00:00 ETAd
d: /dev/rdk15: short write on character device
dd: /dev/rdk15: end of device
976752000+0 records in
7630874+1 records out
500096966144 bytes transferred in 4085.217 secs (122416255 bytes/sec)
100% |***********************************|   465 GiB  116.74 MiB/s    --:-- ETA


and trying the double buffering (is this the right idea?)


quantz# dd if=/dev/zero ibs=64k | dd bs=64k | progress -l 976751887b dd of=/dev/
rdk15 obs=64k                                                                   
 99% |********************************** |   465 GiB  116.04 MiB/s    00:00 ETAd
d: /dev/rdk15: short write on character device
dd: /dev/rdk15: end of device
976752000+0 records in
7630874+1 records out
500096966144 bytes transferred in 4109.835 secs (121682979 bytes/sec)
100% |***********************************|   465 GiB  116.04 MiB/s    --:-- ETA