Will purchasing an NVMe SSD noticably improve performance

[User 11436]

Hi,

... but I've been wondering where the primary performance bottleneck lies in the PBP. Is it the eMMC interface? ...

Ben

Hi Ben, please describe in more detail this performance bottleneck you describe above. I am curious about the context of your observation.

Hi,

I have nothing to point fingers at in particular. It's just that on several occasions when I've been waiting for the PBP, I've noticed that the processor doesn't appear to be pushed.

There's a couple of utilities you can use to get a better understanding of what you're waiting for on those occasions... install 'atop' and 'iotop' if you haven't already. 
'sudo apt install atop iotop'

While you're using the PBP, keep a terminal window open with one or the other(or two windows with both). Run atop with
'atop -d' 
and run iotop with 
'sudo iotop'. 

Keep them running while you use the PBP and when you hit a point where you get a slow down, check those windows. In atop you'll want to look for the row labeled "DSK" and in iotop just look at the top for the disk read/write stats. You'll see spiked activity on those lines if the slow down is releated to the eMMC, as well as the name of the process responsible. If you do see activity, then most likely being able to switch to an SSD should speed things up as far as those phantom waits go.

Did you manage to successfully install both of those on the PBP? systemd through up errors for both of them for me:

Code:

benjamin@Scatha:~$ sudo apt install atop      
Reading package lists... Done
Building dependency tree      
Reading state information... Done
The following NEW packages will be installed:
 atop
0 upgraded, 1 newly installed, 0 to remove and 1 not upgraded.
Need to get 145 kB of archives.
After this operation, 302 kB of additional disk space will be used.
Get:1 http://cdn-fastly.deb.debian.org/debian stretch/main armhf atop armhf 2.2.6-4 [145 kB]
Fetched 145 kB in 0s (240 kB/s)
Selecting previously unselected package atop.
(Reading database ... 371826 files and directories currently installed.)
Preparing to unpack .../atop_2.2.6-4_armhf.deb ...
Unpacking atop (2.2.6-4) ...
Setting up atop (2.2.6-4) ...
Created symlink /etc/systemd/system/multi-user.target.wants/atop.service → /lib/systemd/system/atop.service.
Created symlink /etc/systemd/system/multi-user.target.wants/atopacct.service → /lib/systemd/system/atopacct.service.
Job for atopacct.service failed because a timeout was exceeded.
See "systemctl status atopacct.service" and "journalctl -xe" for details.
invoke-rc.d: initscript atopacct, action "start" failed.
● atopacct.service - Atop process accounting daemon
  Loaded: loaded (/lib/systemd/system/atopacct.service; enabled; vendor preset: enabled)
  Active: failed (Result: timeout) since Sun 2019-11-10 14:05:48 UTC; 38ms ago
    Docs: man:atopacctd(8)
 Process: 3670 ExecStart=/usr/sbin/atopacctd (code=exited, status=0/SUCCESS)

Nov 10 14:04:18 Scatha systemd[1]: Starting Atop process accounting daemon...
Nov 10 14:04:18 Scatha atopacctd[3673]: Version: 2.2.6 - 2016/12/22 00:00:00…nl>
Nov 10 14:04:18 Scatha atopacctd[3670]: receive NETLINK family, errno -2
Nov 10 14:05:48 Scatha systemd[1]: atopacct.service: Start operation timed …ing.
Nov 10 14:05:48 Scatha systemd[1]: Failed to start Atop process accounting …mon.
Nov 10 14:05:48 Scatha systemd[1]: atopacct.service: Unit entered failed state.
Nov 10 14:05:48 Scatha systemd[1]: atopacct.service: Failed with result 'ti…ut'.
Hint: Some lines were ellipsized, use -l to show in full.
dpkg: error processing package atop (--configure):
subprocess installed post-installation script returned error exit status 1
Processing triggers for systemd (232-25+deb9u12) ...
Processing triggers for man-db (2.7.6.1-2) ...
Errors were encountered while processing:
atop
E: Sub-process /usr/bin/dpkg returned an error code (1)
benjamin@Scatha:~$ sudo apt install iotop
Reading package lists... Done
Building dependency tree      
Reading state information... Done
The following NEW packages will be installed:
 iotop
0 upgraded, 1 newly installed, 0 to remove and 1 not upgraded.
1 not fully installed or removed.
Need to get 30.4 kB of archives.
After this operation, 96.3 kB of additional disk space will be used.
Get:1 http://cdn-fastly.deb.debian.org/debian stretch/main armhf iotop armhf 0.6-2 [30.4 kB]
Fetched 30.4 kB in 0s (66.8 kB/s)
Selecting previously unselected package iotop.
(Reading database ... 371852 files and directories currently installed.)
Preparing to unpack .../archives/iotop_0.6-2_armhf.deb ...
Unpacking iotop (0.6-2) ...
Setting up atop (2.2.6-4) ...
Job for atopacct.service failed because of unavailable resources or another system error.
See "systemctl status atopacct.service" and "journalctl -xe" for details.
invoke-rc.d: initscript atopacct, action "start" failed.
● atopacct.service - Atop process accounting daemon
  Loaded: loaded (/lib/systemd/system/atopacct.service; enabled; vendor preset: enabled)
  Active: failed (Result: resources) since Sun 2019-11-10 14:07:02 UTC; 16ms ago
    Docs: man:atopacctd(8)
 Process: 4097 ExecStart=/usr/sbin/atopacctd (code=exited, status=0/SUCCESS)

Nov 10 14:07:02 Scatha systemd[1]: Starting Atop process accounting daemon...
Nov 10 14:07:02 Scatha atopacctd[4097]: /run/pacct_shadow.d: File exists
Nov 10 14:07:02 Scatha systemd[1]: atopacct.service: PID file /run/atopacct…tory
Nov 10 14:07:02 Scatha systemd[1]: Failed to start Atop process accounting …mon.
Nov 10 14:07:02 Scatha systemd[1]: atopacct.service: Unit entered failed state.
Nov 10 14:07:02 Scatha systemd[1]: atopacct.service: Failed with result 're…es'.
Hint: Some lines were ellipsized, use -l to show in full.
dpkg: error processing package atop (--configure):
subprocess installed post-installation script returned error exit status 1
Setting up iotop (0.6-2) ...
Processing triggers for man-db (2.7.6.1-2) ...
Errors were encountered while processing:
atop
E: Sub-process /usr/bin/dpkg returned an error code (1)
benjamin@Scatha:~$ sudo systemctl enable iotop
Failed to enable unit: File iotop.service: No such file or directory

Ben