calibre-parallel.exe twice?

sideburnt · 08-24-2009, 11:14 AM

Is there a reason that Calibre runs two calibre-parallel.exe processes to convert books?

It seems both are taking up 50% CPU and neither is converting quickly due to neither process getting the full amount of CPU it needs.

Wouldn't it make sense to run one conversion process at a time?

For example I have two processes sitting at 24-35mins Running time. 2 MB each file. This is nuts.

kovidgoyal · 08-24-2009, 11:17 AM

It runs as many processes as you have CPU cores.

sideburnt · 08-24-2009, 11:33 AM

aaah, righto, Thanks for the VERY fast reply.
Another quick question then. If you have only one process running why does it ONLY use 50% CPU?

Landrovan · 08-24-2009, 11:36 AM

A process can only run on one core. So if you have 2 core, no process can use more than 50% of the CPU.

Jellby · 08-24-2009, 11:37 AM

Quote:

Originally Posted by sideburnt

aaah, righto, Thanks for the VERY fast reply.
Another quick question then. If you have only one process running why does it ONLY use 50% CPU?

One process can only use a single core. If you have two cores, a single process will always leave one core idle, and depending on how your monitoring software displays things, you'll see CPU usage at 50% (one core at 100%, the other at 0%, more or less).

Nate the great · 08-24-2009, 12:09 PM

Quote:

Originally Posted by kovidgoyal

It runs as many processes as you have CPU cores.

So I guess this means my 1.7GHz pentium-M laptop has 4 cores? I didn't know that.

P.S. Right now it's running 2 calibre-parallel processes in the background.

kovidgoyal · 08-24-2009, 12:41 PM

There are two calibre-parallel.exe processes maintained in the background per core. However only one is actively run at a time per core (unless you happen to add/save books while also converting)

Konrad Vorgen · 03-14-2011, 02:22 PM

Quote:

Originally Posted by kovidgoyal

It runs as many processes as you have CPU cores.

Well I was hoping that until I ran Calibre v.0.7.49 on on my Intel i7 Core-720QM. Yes it has 4 cores and Hyper-Threading.

Actually it seems that there are 3 working threads (yes, there are 6 calibre-parallel.exe processes).

It should be at least 4 working threads (there are 4 cores). In the best situation there should be 8 working threads ( 4 cores multiply by HT). Just to not start another discussion - yes 8 threads are faster than 4 on this CPU - I tested it by Prime.

Can You tell me why it happened?
Thanks for your help.

kovidgoyal · 03-14-2011, 03:14 PM

Because the max number is capped at 6, see preferences->miscellaneous

Konrad Vorgen · 03-15-2011, 01:18 PM

Thanks a lot kovidgoyal.

I knew then there must be parameter somewhere but can't find it

I just changed the settings and now I have 8 working threads (16 calibre-parallel.exe processes). Oh my god, now it really fast

From now on I will be using calibre to test my CPU speed instead of prime

Did I say thank You?

Thank You very much!

Littletart · 03-24-2012, 03:44 PM

Why does this process use up all of my CPU usage? I'm converting some books and I can't use my PC for anything else. I don't need calibre to use so much of my memory. I have two processes and they are using 100% of my memory - I cant even check my email or open a browser window. This is very invasive and hardly seems a reasonable use of my cpu.

theducks · 03-24-2012, 08:07 PM

Quote:

Originally Posted by Littletart

Why does this process use up all of my CPU usage? I'm converting some books and I can't use my PC for anything else. I don't need calibre to use so much of my memory. I have two processes and they are using 100% of my memory - I cant even check my email or open a browser window. This is very invasive and hardly seems a reasonable use of my cpu.

Memory? or CPU cycles?
If you are running out of RAM, you might consider that 512M is not good for much other than reading mail

1 to 2G on XP is sweet for Process intensive programs.
Vista or W7 the sweet spot moves UP to 3 to 4G of RAM

There is a Calibre preference to reduce Priority to LOW, which will allow othe programs (with normal Priority) to run in spite of Calibre.

DoctorOhh · 03-24-2012, 08:51 PM

Quote:

Originally Posted by Littletart

I can't use my PC for anything else. I don't need calibre to use so much of my memory. I have two processes and they are using 100% of my memory - I cant even check my email or open a browser window. This is very invasive and hardly seems a reasonable use of my cpu.

As theducks says go to Preferences - Behavior and change Job Priority from Normal to Low and you'll be able to check email again.

08-24-2009, 11:14 AM	#1
sideburnt Connoisseur Posts: 83 Karma: 46 Join Date: May 2009 Device: Sony prs-505	calibre-parallel.exe twice? Is there a reason that Calibre runs two calibre-parallel.exe processes to convert books? It seems both are taking up 50% CPU and neither is converting quickly due to neither process getting the full amount of CPU it needs. Wouldn't it make sense to run one conversion process at a time? For example I have two processes sitting at 24-35mins Running time. 2 MB each file. This is nuts.

03-15-2011, 01:18 PM	#10
Konrad Vorgen Junior Member Posts: 2 Karma: 10 Join Date: Mar 2011 Device: Kindle 3	Thanks Thanks a lot kovidgoyal. I knew then there must be parameter somewhere but can't find it I just changed the settings and now I have 8 working threads (16 calibre-parallel.exe processes). Oh my god, now it really fast From now on I will be using calibre to test my CPU speed instead of prime Did I say thank You? Thank You very much!

03-24-2012, 03:44 PM	#11
Littletart Junior Member Posts: 3 Karma: 10 Join Date: Mar 2012 Device: Nook	Why such a resource hog? Why does this process use up all of my CPU usage? I'm converting some books and I can't use my PC for anything else. I don't need calibre to use so much of my memory. I have two processes and they are using 100% of my memory - I cant even check my email or open a browser window. This is very invasive and hardly seems a reasonable use of my cpu.

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08-24-2009, 11:17 AM	#2
kovidgoyal creator of calibre Posts: 45,604 Karma: 28548974 Join Date: Oct 2006 Location: Mumbai, India Device: Various	It runs as many processes as you have CPU cores.

08-24-2009, 11:33 AM	#3
sideburnt Connoisseur Posts: 83 Karma: 46 Join Date: May 2009 Device: Sony prs-505	aaah, righto, Thanks for the VERY fast reply. Another quick question then. If you have only one process running why does it ONLY use 50% CPU?

08-24-2009, 11:36 AM	#4
Landrovan Enthusiast Posts: 42 Karma: 14 Join Date: Jul 2009 Device: dr800sg	A process can only run on one core. So if you have 2 core, no process can use more than 50% of the CPU.

08-24-2009, 12:41 PM	#7
kovidgoyal creator of calibre Posts: 45,604 Karma: 28548974 Join Date: Oct 2006 Location: Mumbai, India Device: Various	There are two calibre-parallel.exe processes maintained in the background per core. However only one is actively run at a time per core (unless you happen to add/save books while also converting)

03-14-2011, 03:14 PM	#9
kovidgoyal creator of calibre Posts: 45,604 Karma: 28548974 Join Date: Oct 2006 Location: Mumbai, India Device: Various	Because the max number is capped at 6, see preferences->miscellaneous