Not using all CPU

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Message 7234 - Posted: 30 Dec 2007, 19:24:33 UTC

I\'m having blender.exe sometimes using 30% CPU instead of 50% CPU (I have a dual core). This matches big changes in memory usage, as if it was allocating/freeing a lot of memory. This is with session 718.


Note that the first 50% is used by another project. Total CPU usage during that low period was 60%-70%, which means 50% by RieselSieve and 10-20% from BURP.

Swapping is definitely not the problem: 2GB physical memory, 720MB total virtual memory in use, BURP using only 140MB.

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Message 7240 - Posted: 31 Dec 2007, 2:56:14 UTC

I\'ve noticed the same thing on my q6600... my best guess is the calculations used don\'t need the full CPU power 100% of the time. However, it is not something that I watch closely unless it is mentioned.

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Message 7242 - Posted: 31 Dec 2007, 4:27:47 UTC - in response to Message 7234.  

I\'m now suspending BURP until this problem is fixed; I don\'t like idle CPU time.
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Message 7244 - Posted: 31 Dec 2007, 6:03:22 UTC

How many seconds/minutes/hours did that low period last?
and/or
What is your update speed set to in Windows Task Manager -> View -> Update Speed ?
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Message 7245 - Posted: 31 Dec 2007, 7:13:09 UTC - in response to Message 7244.  

How many seconds/minutes/hours did that low period last?
and/or
What is your update speed set to in Windows Task Manager -> View -> Update Speed ?


on mine, 1 square = 6 seconds. Update speed is once per second, could also be whatever was crunched being written to the file during the \"downtime\". Not sure.
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Message 7247 - Posted: 31 Dec 2007, 11:03:53 UTC

Some sessions are heavily memory intensive. During such sessions it may happen that the system (especially in the case of multicore systems running other memory intensive applications) will have to wait for the memory to be ready.

If you can reproduce the situation you can try to temporarily suspend whatever runs on the other cores and see if this boosts Blender\'s CPU usage.
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Message 7252 - Posted: 1 Jan 2008, 3:54:52 UTC

Aside from the occasional virus scan/defrag, this box is a web browser box. I have a dedicated computer for the memory intensive stuff.

Running 1-2 BURP tasks only (changing the processor allowance) stabilizes out the hiccup, but that is not an efficient use of the quad-core leaving 2 idle (or splitting 2 tasks across all 4 cores however it works).

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Message 7253 - Posted: 1 Jan 2008, 18:06:25 UTC - in response to Message 7247.  

Some sessions are heavily memory intensive. During such sessions it may happen that the system (especially in the case of multicore systems running other memory intensive applications) will have to wait for the memory to be ready.

If you can reproduce the situation you can try to temporarily suspend whatever runs on the other cores and see if this boosts Blender\'s CPU usage.

I have only ever seen this with BURP, and with recent sessions. SIMAP allocates and frees a lot of memory *all* the time, and its CPU usage stays quite constant.
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Message 7254 - Posted: 1 Jan 2008, 18:06:55 UTC - in response to Message 7244.  

How many seconds/minutes/hours did that low period last?

Less than a minute.
What is your update speed set to in Windows Task Manager -> View -> Update Speed ?

The fastest it can go: twice a second.
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Message 7257 - Posted: 1 Jan 2008, 19:07:01 UTC - in response to Message 7253.  

I have only ever seen this with BURP, and with recent sessions. SIMAP allocates and frees a lot of memory *all* the time, and its CPU usage stays quite constant.

Only very few sessions are this memory bound. Most are highly CPU bound due to the raytracing.
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Message 7264 - Posted: 2 Jan 2008, 5:48:21 UTC - in response to Message 7252.  

Aside from the occasional virus scan/defrag, this box is a web browser box. I have a dedicated computer for the memory intensive stuff.


You use a Core2 Quad for the sole purpose of browsing the web? Geez!
Click here to see My Detailed BOINC Stats
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Message 7265 - Posted: 2 Jan 2008, 7:55:06 UTC

You use a Core2 Quad for the sole purpose of browsing the web? Geez!


Not soley. No highspeed internet (no providers offer service where I live) really limits what I can do w/ this rig, so it runs BOINC.

http://boincstats.com/stats/boinc_host_graph.php?pr=bo&id=3133954

I have a C2D laptop (on XP Pro) for everything else and a second laptop that I just took off BOINC due to heat issues.
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Message 7274 - Posted: 2 Jan 2008, 18:25:47 UTC - in response to Message 7254.  

The fastest it can go: twice a second.

It\'s really the slowest that I was wondering about... which is something like once every 4 seconds, so yeah, the pictured gap is probably at most ~4 min.
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Message 7276 - Posted: 3 Jan 2008, 4:31:37 UTC - in response to Message 7274.  

The fastest it can go: twice a second.

It\'s really the slowest that I was wondering about... which is something like once every 4 seconds, so yeah, the pictured gap is probably at most ~4 min.

I had mine set at twice a second. The pictured gap on my screenshot was less than a minute, iirc.
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Message 7280 - Posted: 3 Jan 2008, 7:25:58 UTC - in response to Message 7265.  

Not soley. No highspeed internet (no providers offer service where I live) really limits what I can do w/ this rig, so it runs BOINC.

http://boincstats.com/stats/boinc_host_graph.php?pr=bo&id=3133954

I have a C2D laptop (on XP Pro) for everything else and a second laptop that I just took off BOINC due to heat issues.


Intended to be a gaming rig? I was just gawking, as my daily-user desktop is a P3-550. It never ceases to amaze me, how many people really do buy a new computer every year, just to surf the web and run Office. Absolutely insane, and wasteful, if you ask me.

I had to limit my (Pentium 4 w/HT) laptop to 1 \"CPU\" in BOINC, as I managed to melt the first one--the plastic around the fan deformed, and my USB ports (located next to the cooling block) also stopped working. Fortunately, it was covered under warranty and the replacement has run fine for almost two years now.
Click here to see My Detailed BOINC Stats
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Message 7286 - Posted: 4 Jan 2008, 2:13:25 UTC - in response to Message 7280.  



Intended to be a gaming rig? I was just gawking, as my daily-user desktop is a P3-550. It never ceases to amaze me, how many people really do buy a new computer every year, just to surf the web and run Office. Absolutely insane, and wasteful, if you ask me.


Kind of... To get to a gaming rig status I\'d need new RAM, vid card and better CPU cooler. It was more-so built to be a cruncher.
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Message boards : Number crunching : Not using all CPU