Playback issues / High CPU usage when using large soundfont (sf2) on laptop

• Jan 27, 2015 - 15:20
S4 - Minor

MuseScore 2.0 beta 2
Using SGM-v2.01.sf2 SoundFont.
On desktop (Intel Core i5-2400 Quad-Core 4 threads) playback is smooth, everything is fine.
On laptop (Intel Core i5-4200U Dual-Core HT 4 threads) playback stutters when more than 3 notes are playing at the same time. The CPU usage rises to 19-25% which maxes out one thread on the CPU.
Memory usage is not an issue since the SoundFont is 250MB and there is plenty of free memory.
Editing the soundfont in Polyphone and removing all non-GM instruments seems to have fixed it but the sf2 file size has not decreased by much


What OS? It's probably somewhat unavoidable that large soundfonts will take lots of memory and CPU, but there may be things that can be done to improve the situation.

Laptop is running Windows 8.1
As mentioned in the last line, it was not the file size that affected it. After editing the file, CPU usage decreased to ~5% (vs ~20%) and the file size was 225MB (vs 250MB that it was at first) but the soundfont now contains only GM instruments (bank number 0 + a drumset) while before it had many more instruments and drumsets