Some theory first:
https://forums.guru3d.com/threads/windows-line-based-vs-message-signaled-based-interrupts-msi-tool.3...
https://en.wikipedia.org/wiki/Message_Signaled_Interrupts
Been tweaking this setting in registry, trying to fix issues on certain old titles - mainly stutterring. So far:
When driver is set to LineBased mode:
- no measurable performance penalty
- Uses up to 150 ISR and 150 DPC calls, taking 3-5 miliseconds over 1 minute benchmark when idle.
When driver is set to MSI mode:
- no measurable performance benefit nor penalty
- Uses DPC calls only, taking 0,7 milisecond over 1 minute benchmark when system is idle.
Few questions:
1. What is currently the default mode for the Radeon GPU drivers?
2. Will there be support for MSI-X mode?
