Re: RPi4+UEFI/ACPI---how to choose root partition?

[Sad Clouds <cryintothebluesky%gmail.com@localhost>]

On Wed, 8 Jul 2020 12:47:22 -0700
Jason Thorpe <thorpej%me.com@localhost> wrote:

> 
> > On Jul 8, 2020, at 11:51 AM, Sad Clouds
> > <cryintothebluesky%gmail.com@localhost> wrote:
> > 
> > Sorry, don't have the answer to your question, but you mentioned
> > SSD on USB3, so wanted to ask if NetBSD on RPi4 is using USB3 to its
> > full potential? Some time ago I did a test with USB3 stick and
> > throughput was not very good.
> 
> In order to fix that, someone is going to need to write a UAS / UASP
> driver for NetBSD.  Right now, "umass" only supports CBI, CBI+CCI,
> and BBB/BOT.
> 
> -- thorpej
> 

Hi, I've just realised, the problem was actually USB3 flash stick, with
proper SSD it would have been much better.

I have SanDisk Ultra Fit 64 GB and it turns out write throughput is
capped at 40 MiB/sec, which I assume is due to flash technology. When
reading from the same device on NetBSD-current with RPi4, I get around 117
MiB/sec, which is pretty good compared to the SD card.

I hate when manufacturers use vague slogans like "Speed up to 130 MB/s".
Yeah, maybe, but only when reading.

[   118.439992] umass0 at uhub0 port 2 configuration 1 interface 0
[   118.439992] umass0: SanDisk (0x0781) Ultra Fit (0x5583), rev 3.00/1.00, addr 4
[   118.452581] umass0: using SCSI over Bulk-Only

arm64# dd if=/dev/rsd0c of=/dev/null bs=1m count=1000
1000+0 records in
1000+0 records out
1048576000 bytes transferred in 8.951 secs (117146240 bytes/sec)