I recently started to learn QGIS system and used quite well to develop a project. I wanted to have faster outputs so I bought a new desktop.

The old one specification is like this:

  • CPU intel i5-7400 CPU @ 3Ghz
  • 8GB RAM
  • No extentional VGA

and new one is like this:

  • CPU AMD Ryzen 9 3900 (12 core, 24 threads)
  • 64GB RAM
  • VGA GeForce RTX2080 Ti

Yes, I put much money to see higher performance but it is totally slower than before for making even simple joining by location.

Is there any hint of reason?

Other environments are same like Windows 10 / QGIS 3.8 / sets all the settings and options between old and new one.

I can't understand...

closed as primarily opinion-based by Vince, Fran Raga, HDunn, TomazicM, Jochen Schwarze Aug 8 at 12:24

Many good questions generate some degree of opinion based on expert experience, but answers to this question will tend to be almost entirely based on opinions, rather than facts, references, or specific expertise. If this question can be reworded to fit the rules in the help center, please edit the question.

  • 1
    Welcome to GIS.SE. What kind of data you have ? all your data in shape files or in database ? Also let us know your objective that you want to achieve in QGIS – Sunil Aug 8 at 7:00
  • yes, grid.shp (in points 50m x 50m, 242000 points) and polygons.shp(boundary shape) and wanted to make attributes joined into grids. and did join by location. – Dong Gil Lee Aug 8 at 7:21
  • The QGIS version you use now and the version you used then are the same? I have experienced some performance issues when I update from QGIS 2.18 to QGIS 3.6 (the same project I used is taking much more time to load) – Carlos MSF Aug 8 at 9:32
  • yes, before and after is on QGIS 3.8 latetest version. also I am trying same works on each versions I think hardware or software setting has problem. when it processes algorithm cpu usage is less than 10% I check Using multiple threads on rendering but it is not on rendering but processing simple algorithm. Is there any possiblity about cpu virtualizations or performance related to power setting....? or is it too much new cpu product....? – Dong Gil Lee Aug 8 at 9:46
  • @dolgil2 - In Settings > Options > Accelaration, there is an option to increase performance of core algorithms and rendering if you have a recognised OpenCL device. Note: this is experimental and may crash QGIS. Another option is to create a virtual layer or use PostGIS for large datasets. – Joseph Aug 8 at 10:02

I'm not a specialist on these matter but after some internet reading I gather that :

  • Processing mostly (?) use a single one Core. (so it's possible that one core of your new processor is less efficient than one core from your old processor, even if the total processing power is far superior)
  • Processing doesn't use the GPU so any upgrade in that area is worthless.
  • One of the main factor for speed is the time spend to read an write data so getting faster hard drive / faster memory / faster network... is often the best way to better performance
  • now i am able to understand. Thank you so much! and sorry for making not so much related questions on unsuitable place. Thank you again – Dong Gil Lee Aug 9 at 0:58

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