On my 2 GHz ACER laptop with 2 GB memory top says java 30% when the waterfall is active, and 20% when I am on another tab.
It uses only 3% of memory. As long as the machine does not swap, memory shoould not be a problem,
for lubuntu 12.04 512 MB is more than enough.
The combination of jpskmail-1.5.9 and fldigi takes 6% + 13%.
On the new dual core desktop machine jpskmail-2.0.13 takes 11%,
the combination of jpskmail-1.5.9 and fldigi takes 2% + 10%.
Maybe something else is hogging the CPU?
Can you make a screendump of top?
Which java version are you running? (java -version).
I decided to give 2.0.13 a try today. I could not get it to work as it should, it brings my PC to a slow crawl! When it beaconed the audio was barely able to create a couple of screeches. I tried both the default audio and the pulse audio. Both running on vox and they both acted the same. My pc has only 1GB of ram, is that it? Rein said that his works and uses a small percentage of resources. On this it uses all the resources.
On the other hand the 1.5.9 client runs very smoothly, and fast, no problems at all.
Very 73 to all, Glenn WB2LMV