ResultOutput in VTU too slow

[888]

Hi!

Its true that the case im working at is quite big (about 1,2 million nodes and more than 7 million FE), however the write rate of the .vtu (Binary Output) file seems too low, aprox 200-300 KB/s, so saving the 220MB results file takes too long.
Its taking almost the same time that the Solver .

Im using the 64bits version of Elmer donwloaded from sourceforge, maybe could there be some bug? or is it normal that takes this long?

[Juha]

Hi,

i think there has been some slow I/O 'features' in gfortran/gcc on windows platforms from time to time.
Any chance someone testing some case both on windows & linux (with comparable hardware) and
reporting back?

RGDS, Juha

[888]

Considering this last info and the fact that compiling under Windows is far from been easy, I will probably be testing in this same PC the CAElinux distro in the near future, if all goes smoothly, so ill report back as soon i have something.

Thanks!!

[raback]

Hi

You might also try our tailorder Linux Mint VMWare virtual machine
http://www.nic.funet.fi/pub/sci/physics ... LinuxMint/

-Peter

[888]

How that VMware version works exactly? i mean, its an standalone version or i need the virtualization software? also, how much performance penalty is expected? (avaible amount of RAM for instance, the PC has 8GB)

Im planning to run CAELinux from a USB key, writing and reading from HDD anything that isnt software.

[888]

Confirmed, using Elmer 5216 (64bits) under CAELinux the ResultOutput only take 10 seconds, againt the 5 to 10 minutes that was taking under Windows.

[raback]

Hi

Ok, good to know.

To be on the safe side, in the current svn version the binary output is buffered (since a few days). The length of the buffer is by default the same as number of nodes.

I also recently changed the default to "binary" from "ascii" since the binary seems to work nicely, it saves time and is faster. One can still choose "Binary Output = False" or equivalently "Ascii Output = True". So if there are some problems due to these changes, I'm happy to recieve bug reports.

BR, Peter

[Juha]

Hi,
Thanks for testing Linux vs Windows! I think the windows problem can be solved
by updating the compilers. I'll do that for our build machines, hopefully this week.
Regards, Juha