[scribus] Scribus on 'modern' machines

[Craig Ringer]

John Beardmore wrote:
>
> Amount of memory doesn't seem to be a bottleneck, so my guess is that 
> CPU and memory speed are likely to be the main rate determining 
> characteristics.
>
>   
Do keep an eye on your free RAM during heavy operations. Scribus likes 
*LOTS* of RAM, and if you're swapping even a little bit your performance 
will suffer considerably.

It's often informative to run the command "vmstat 5" in a terminal. 
That'll print some summary system activity data every 5 seconds. You are 
interested in the "swap" columns - you do not want to see anything but 
zeroes in the "si" and "so" columns most of the time. If your system 
starts swapping more than very occasionally, and especially if it does 
so when the "cache" memory column in vmstat begins falling rapidly, then 
you might benefit from more RAM.
> I guess faster memory and CPU might improve editing speed a little, but 
> I assume given Craigs comment, that the extra CPU core won't help much 
> there.  Is that right ?
>   
Correct. It will help the rest of your system remain more responsive 
while Scribus is hogging the CPU, but it will not detectably improve 
Scribus's performance. A second core can help single threaded 
applications if they're doing lots of async I/O or network 
communication, but Scribus does neither of those and won't benefit.
> But will a second core help more with printing ?  In other words, does 
> any part of the printing process run in a separate thread that might 
> benefit from a second core ?
>   
Probably not any part that takes a significant amount of time. You'll 
find that almost all the time is spent in the Scribus process preparing 
the job; the later parts of the printing process probably happen very 
quickly. You can verify this by running:

"watch lpstat"

and kicking off a Scribus print job. When a job appears in the "watch 
lpstat" window, Scribus has handed the print job off to the print system 
for processing. Before that a second core will not help. After that, 
though, Scribus is probably basically idle, and the print system will 
most likely only use one core for processing the job. However, you'll 
find that the print system gets it done quickly enough that you won't care.

If you're thinking of upgrading it's certainly best to focus on maximum 
performance per core rather than on the number of cores.

By the way, many applications (but not Scribus most of of the time) 
benefit quite significantly from a fast hard disk, as does general 
system responsiveness. I have the same laptop as two of my workmates, 
but they got it with only 2GB of RAM and with a 5400rpm HDD. My machine 
is *massively* faster, and it's almost all down to the 7200rpm hard disk 
though the extra 2GB of RAM does help with caching. Similarly, a friend 
built a desktop with a Western Digital Raptor 150 (a 10,000rpm SATA hard 
disk) and the performance benefits are quite impressive. Boot times and 
program launch times are massively improved as well. So - if you're 
using lots of other apps on there, not just Scribus, or you value 
general system responsiveness a fast disk is worth thinking about. Don't 
bother for Scribus, though, as it will not gain very much from a fast disk.

--
Craig Ringer