Extremely woeful performance on a modern i7 CPU

[freq-mod]

I came to conclusion it cannot be explained in any other way but some kind of a regression, either in kernel, DE or furnace itself.

CPU: Intel Core i7-8650U (4 cores, 8 threads, 0.4 - 4.2 GHz)
GPU: Intel UHD 620
RAM: 16 GB DDR4
OS: Arch Linux
Kernel ver: 6.11.9

All of this amount to noticeable pops and sound stutter even on single Nuked-OPN2 instance, even more so on dual Nuked-OPN2, furnace's reported CPU load spikes to ~100% constantly (no more than 25% on KDE's system monitor). -O2 gcc flag hardly helped. Nuked-OPM is a lagfest. i5-10505 CPU in my desktop doesn't exhibit that problems. Neither should rather modern mobile i7, so where is the problem? This computer has no problem running 7 concurrent Nuked OPL3 cores, as evidenced by libADLMIDI.

Setting cpupower to performance helps, but that introduces extreme crackling on all chips.

At all times, furnace reports 60 fps 16 ms render time
Driver is SDL

[freq-mod]

P.S: SID core is reSIDfp, steady 50% CPU use, no crackling

[tildearrow]

Rationale for closure?

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Turns out it's not an OS issue - it's even worse on Ubuntu Linux 24.10. Even intro lags! Meanwhile, BambooTracker runs perfectly fine, with Nuked OPN-Mod, 192 kHz and 3ms buffer

[tildearrow]

Doubt this will solve it, but try using PortAudio backend.

[freq-mod]

Sadly didn't help.

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https://github.com/user-attachments/assets/05b2db7d-d4e0-4cbb-92ff-2f181a637fea to more properly explain the problem, I recorded a video (with external camera, to eliminate any way software capture would affect this. Audio volume is low (sadly) but crackling can be audibly heard. Also system monitor shows Furnace eats actually only 8-9% of total CPU power.

[freq-mod]

I finally decided to give JACK a try out of desperation: it works... as long as you dont open another window like web browser. Then the playback varies between is like YM2608-LLE realtime playback on a normal computer or simply lags, depending on a core (Nuked OPM and ymfm OPM/Nuked OPN2 respectively).... i have no idea what else to try

[freq-mod]

Performance seems noticeably better on Windows 11, to the point where crackling only persists on Nuked OPM and Ultimate quality emulation