GM 14.1 much slower than GM 13.2?

DGriffithDGriffith Global Mapper UserPosts: 70Trusted User
edited April 2013 in Technical Support
We have GM 14.1 64bit running on Windows 8 64 bit with 8GB of memory on a fast new laptop and GM 13.2 running on Windows XP SP3 with 3 GB of memory on a five year old laptop. I had the general impression that 14.1 was running significantly slower than 13.2 and so did a side by side test using the same files. The GM workspace file loaded about 100 MB in 18 .pdf files, rectified and cropped them. While I know that the subroutine GM uses for reading the .pdf files is slow, I didn't expect that it would be a lot slower in 14.1. It took about twice the time to open the workspace in 14.1 as it did in 13.2.

In a second test I zoomed in to a small area of the screen and then zoomed out to the full extents. The zoom in was equally quick but the zoom out to full extents was again significantly slower under 14.1. I then exited both 14.1 and 13.2.

The speed difference is significant. What can take 15 minutes using 13.2 can take over 30 minutes using 14.1 and while GM 14.1 is working away the computer effectively can't be used for anything else.

In all cases there was constant disk activity under 14.1 whereas under 13.2 it was only intermittent. Under 14.1 the constant disk activity continued several minutes after I exited GM, whereas under 13.2 it ceased almost immediately. My impression is that 14.1 or perhaps Windows 8 does not manage memory and/or disk caching well, but other programs such as AutoCAD 64 bit run much faster on Windows 8 64 bit than the equivalent versions on XP.

Are there any settings I can change to get GM 14.1 64 bit on Windows 8 64 bit running faster? Hopefully at least as fast as 13.2 under Windows XP.

Thanks in advance for any suggestions.
David

Comments

  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited April 2013
    David,

    I think the issue is almost entirely related to the use of .pdf files. In older versions Global Mapper would load the PDF files at a lower DPI (resolution) by default, so you were actually getting a less detailed representation of the PDF file (particularly in 64-bit). Because GM v14 loads a more detailed version it often has to be written to disk and streamed from there to avoid filling up memory. This allows you to get many more PDF files loaded with higher quality, but at the expense of slower draw times and also unload times as the files are deleted.

    There is a way in the latest v14 builds to override the default PDF DPI with one that you want used. You can run 'regedit' and add a DWORD value in 'HKEY_CURRENT_USER\Software\GlobalMapper' named 'PDF_RENDER_DPI' and set the value to '300' (in decimal, not hex), then see if that is better (except for the PDF detail, which would be less). I have placed a new build at http://www.bluemarblegeo.com/downloads/global-mapper/global_mapper14.zip with the latest changes for you to try. Simply download that file and extract the contents into your existing v14.xx installation folder to give it a try. If you are using the 64-bit v14 version there is a new build at http://www.bluemarblegeo.com/downloads/global-mapper/global_mapper14_64bit.zip .

    Another solution is to batch convert the PDF files to a format that is much quicker and less memory intensive to deal with, like GeoTIFF, using the File->Batch Convert/Reproject menu command.

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    Blue Marble Geographics for Coordinate Conversion, Image Reprojection and Vector Translation
  • DGriffithDGriffith Global Mapper User Posts: 70Trusted User
    edited April 2013
    Mike,

    Thanks, I'll try that. In this case I am using GM mapper to import and reproject the .pdf files as Geotiff files which I subsequently use, but the process has been frustratingly slow. I'll let you know how it worked.
  • DGriffithDGriffith Global Mapper User Posts: 70Trusted User
    edited April 2013
    Mike,

    That definitely fixed it. Out of curiosity what is the default dpi under 14.1 64 bit and what was the default dpi under 13.2?

    Once again, thanks.
    David
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited April 2013
    David,

    It's actually a bit complicated. The max DPI was the same (600), but that would only be used on v13.2 if the PDF dimensions coupled with that DPI resulted in less than 64MB of size to save the rendered result. In v14 the 600 DPI is allowed up to 256MB of rendered size. If the size is still over that then lower DPIs are tried (like 400, then 300, etc.). In v14 you will likely get 600 or 400 DPI whereas in v13.2 you would probably get 300 DPI, at least for normal letter size.

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    Blue Marble Geographics for Coordinate Conversion, Image Reprojection and Vector Translation
  • DGriffithDGriffith Global Mapper User Posts: 70Trusted User
    edited April 2013
    Mike,

    OK, one last (I hope) question. I now have 8 GB of memory on the machine running GM 14.1 64 bit on Windows 8 64 bit. If I add more memory, say going to 16 GB, will GM take advantage of it automatically.

    Thanks in advance,
    David
  • global_mapperglobal_mapper Administrator Posts: 17,238
    edited April 2013
    David,

    If you are loading data that resides in memory then it will be much faster if your system utilization ever would top 8GB. Most raster formats are read from disk on demand with some in-memory caching for performance. For PDF files the size that will be stored in memory before going out to disk is based partially on your total available system memory, so adding to that will cause GM to keep more of the PDF files in memory before sending them out to disk. For layers where that happens there will be a big performance benefit, especially for drawing.

    Thanks,

    Mike
    Global Mapper Guru
    gmsupport@bluemarblegeo.com
    Blue Marble Geographics for Coordinate Conversion, Image Reprojection and Vector Translation
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