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Heavy load

Ever tried to do a serious stress test while you where still using your system? I have. No so much on purpose byt by accident. I was looking at the program SweetHome 3D. The program is freely available for download and can make home interiors.

I made a quick render of some fantasy house. It can be downloaded here and put into your own SweetHome program. If you use it for a real house, do not blame me if the house falls down, but I would love to visit it or at least see pictures of it.
There are some errors. Toilet is wrong way around and the hallway has a wrong ceiling. This program can make a screenshot, like this one, but it also can make a walktrough as can be seen just below.

And now to the technical part. I did a walktrough with the size 480x360 on the highest quality, which took more then 48 hours on my quad 2833 system with 8GB of memory. Also the reason I did not go for 1920x1080. The main spoiler is the quality. A 1920x1080 on low quality would take between 1 and 3 hours. At the same time I was still working on my system. One of the things I was working on was MRTG. Just for fun.

So here are the different MRTG stats that might be interesting:

MRTG Load Data
Blue is the 1 minute and green is the 15 minute load average.

This is multiplied by 100. The reason is that MRTG does not seem to work well with decimal numbers. I have not yet looked into it as it should be possible, but this, for now, works. The white part was because the script (See below) I used did some errors on calculating the uptime, which then caused an error after uptime went, well up.

If you look closely, the load when only doing the rendering iq around 4.2, which is not too bad for a 4CPU PC. (Some interesting info about load here).
The moments it went up I was doing other things as well. However I must say that although I noticed delays in the rendering or better the time it took, the PC never had any issue. Everything still worked, smoothly.
The only issue I had was during the watching of a movie on another PC in 1920x1200 quality over sshfs where it would go a bit wrong. I assume because both ssh was lagging as well as the router was unable to cope with the amount of data.

MRTG Temperature Data
Blue is the CPU and green is the MB temerature in C.

During the rendering, the temerature was around 60C. Outside was 11C and although it was not cold inside, I still decided to close the window and it went slowely to 68C at which moment I opend the window again. The moment it all stopped, the CPU temp went down dramatically.

The PC is watercooled and what is nice is to see that a very importand thing in cooling is the enviromental temperature. So passive cooling, like water cooling or air cooling is not the ultimate. People call using a fan active, but all it does is take the CPU in the direction of the temperature the room is in.
What one should have is a small fridge that realy cools the cooliant for the CPU. If you have meat, fruit or beer, you do not put it in front of a fan and say it is cooled. You put it in a fridge.
Perhaps reworking a minature fridge could do the trick. Should not be to hard to let the cooliand get trough this one or this one. Well, you get the idea.

MRTG Memory Data
Blue is the memory and green is cached memory.

This one is interesting as it shows a bit how memory is used. I did not have anything up for swap, but that was almost empty all of the time. And even after the rendering was stopped, it went on using the memory. This is a feature, not a bug. Only after a serious amount of time did it started to go down. Even then not by much. Do not forget: If you do not use memory, you are doing it wrongly.

Memory usage is pretty cheap for the OS, or should be, where swap is expensive for the OS. There is no cost in keeping stuff in memory, so why remove it?

Here are the files I used to set up MRTG.
mrtg.rc The config file placed in
mrtg_load Script to get the load.
mrtg_temp Script to get the temperature.
mrtg_localmem Script to check the memory status
style.css Style sheet used to get what I want. Rename if you want to use it.
Obviously you must read more about MRTG for the configuration. And these things are not even what MRTG does best, but it is neat.

The command to run the configuration is

/usr/bin/indexmaker \
--output=/srv/www/vhost/local/mrtg/index.html \
--columns=1  \
--compact \
--sidebyside \
--nolegend \
"--addhead=" \
"--title=Router connection" \
/etc/mrtg.rc
I know. A lot of useless information. Perhaps somebody can abuse it and do something with it.