View Issue Details

IDProjectCategoryView StatusLast Update
0000923OpenMPT[All Projects] Feature Requestpublic2017-03-04 15:03
ReporterMonsterovichAssigned To 
Status newResolutionopen 
PlatformLinuxOSLinux Mint (kernel 4.10)OS Version18.1
Product VersionOpenMPT 1.27.00.* (current testing) 
Target VersionFixed in Version 
Summary0000923: Performance problems with VST plugins and multi-core support in OpenMPT

We know that a lot of VST plugins are very CPU hungry. It became a problem on modern machines with multiple cores. For example: I can normally play my song with 4-6 VSTs on 13-year-old CPU (only 1 core) and it will work fine without issues but OpenMPT stucks on my modern laptop (with 4 cores!!!).

I described this problem here:

Despite the fact that the tests show: 1 intel core is almost equal to 1 amd core, these cores on my laptop are very slow by some reason in OpenMPT (probably bad hardware) and I can use only 25% (!) of my processor. Imagine, if I had 8 core processor but the cores are slow.

Allow users to use multiple cores and bind each VST plugin to specific core. (see attachment)
Or just spread VSTs between cores automatically like Renoise does.

Additional Information

I don't have such problems in Renoise. Almost all modern DAWs have this feature.

P.S. I use wine but I have the same thing in Windows on my machine... anyway...

TagsNo tags attached.
Has the bug occurred in previous versions?Yes
Tested code revision (in case you know it)




2017-03-04 14:29


mptmulticore.png (94,646 bytes)
mptmulticore.png (94,646 bytes)


2017-03-04 15:03

administrator   ~0002901

Slowness of pattern display in Wine is at least partly due to the work-around I added in r4043 . Otherwise the current row highlight would be jumpy and flickery like crazy. Now, the flickering could be attributed to an incompatibility in Wine because native Windows behaves differently, however, the way OpenMPT does its drawing of the pattern display here is way suboptimal and IMHO also massively contributes to the problem. Correct behaviour for the way OpenMPT does its drawing is also not at all specified by Microsoft. The work-around that gets applied on Wine basically redraws the whole thing on every row change, which can be noticeably slow, especially on very slow CPUs like an Intel Atom ZxxxxF.

Issue History

Date Modified Username Field Change
2017-03-04 14:29 Monsterovich New Issue
2017-03-04 14:29 Monsterovich File Added: mptmulticore.png
2017-03-04 14:30 Monsterovich Description Updated View Revisions
2017-03-04 14:37 Monsterovich Description Updated View Revisions
2017-03-04 14:37 Monsterovich Steps to Reproduce Updated View Revisions
2017-03-04 14:47 Monsterovich Reproducibility have not tried => always
2017-03-04 14:51 Monsterovich Description Updated View Revisions
2017-03-04 15:03 manx Note Added: 0002901