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Not being sure if this question belongs in here, but anyway. I am a quite long time user of JOSM, and for the last two years, all of the common desktop machines I've used all are able to offer a somewhat decent level of performance running JOSM.

By "decent" I mean, scrolling/zooming is not too laggy, search operations are quick, high command (via mouse and keyboard) responsiveness, validation is quick, able to work with a few hundred GPX files open at the same time, etc.

However, I just acquired a new 4k display, and now JOSM's performance is abysmal. That is expected, since the previous display setup was just a pair of common HD (1080) ones. Another machine I've used for some time had a 2k display, and it ran JOSM just OK (but not anything near "greatly").

My question is about what should be my next upgrade (or upgrades). Should I invest in a high end video card? (current is an very ancient AMD) Higher end CPU? (current one is i7-3770) More memory? (currently with 32GB, but nowhere near full use running JOSM) Anything else?

Rephrasing it, what would be a good desktop configuration for running JOSM @4k resolutions?

asked 04 Jan '16, 15:09

MCPicoli's gravatar image

accept rate: 24%


Remember that to make use of more of your system's memory you need to start JOSM with a -Xmx...m argument. Experiment with a heavy session to see how high a setting is worthwile for you.

(04 Jan '16, 22:09) Vincent de P... ♦

@Vincent de Phily: Indeed - took me a while to understand why it's only using a little bit of memory. Assigning more of the available RAM helps a lot.

(05 Jan '16, 06:30) Piskvor

Increasing memory (tried giving JOSM 2GB using the 32-bit JVM and up to 20GB using the 64-bit JVM with "-d64" just in case) caused little perceivable improvement.

(05 Jan '16, 11:36) MCPicoli

Did you find anything that helped (or was holding you back)? I'm considering a new machine and 4k monitor and wondering how important the graphics card is.

(11 Mar '21, 18:58) TrekClimbing

It would be a annoying to set the screen to a lower resolution for JOSM but if it works it might be less annoying than slow updates. My WIN10 view.

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answered 11 Mar '21, 23:32

andy%20mackey's gravatar image

andy mackey
accept rate: 4%

I agree that's a workaround if you can't fix the hardware, but it would be a shame to buy a 4k monitor and then not be able to use it well for osm editing.

(11 Mar '21, 23:42) TrekClimbing

Agreed, I wonder what JOSMs true maximum resolution is, 1K stretched to 4K may look nicer but is it of use? or have i got this wrong?

(12 Mar '21, 06:55) andy mackey

look at CPU usage graphs (separated by core, although for me JOSM is nicely multithreading), if a single cpu core is clearly over 75% (assuming some kind of averaging), then it may be slowing down the whole. You need to search for the weakest link in your config. It may be your CPU, your buses, you memory speed, your graphics card, your graphics drivers/system, or even another OS ... Likely it is not your storage - but again: look at its usage when JOSM is slow. And in any case: having a SSD is a really paying-off thing for program starts.

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answered 05 Jan '16, 22:47

aseerel4c26's gravatar image

aseerel4c26 ♦
accept rate: 18%

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question asked: 04 Jan '16, 15:09

question was seen: 3,952 times

last updated: 12 Mar '21, 06:55

NOTICE: is no longer in use from 1st March 2024. Please use the OpenStreetMap Community Forum