diff --git a/docs/faq.md b/docs/faq.md index c0cdc5c8..d5504d7e 100644 --- a/docs/faq.md +++ b/docs/faq.md @@ -80,11 +80,6 @@ while higan waits for a video frame to be shown, and video is likely to stutter while higan waits for an audio buffer to complete. -Games run too slow ------------------- - -TODO: pin the CPU governor on Linux, get a faster computer, try different audio drivers. - Games run too fast ------------------ @@ -109,6 +104,54 @@ If games are running way too fast, here's some things to check: [vsync]: #i-see-tearing-when-a-game-scrolls-how-can-i-enable-vsync +Games run too slow +------------------ + +Of all the consoles higan can emulate, +higan's Super Famicom emulation +is the most resource intensive. +Full-speed emulation for the Super Famicom base unit +requires an Intel Core 2 Duo (or AMD equivalent), +full-speed for games with the SuperFX chip +requires an Intel Ivy Bridge (or equivalent), +full-speed for the wireframe animations in Mega Man X2 +requires an even faster computer. +Low-power CPUs like ARM chips, +or Intel Atom and Celeron CPUS +generally aren't fast enough to emulate the Super Famicom with higan, +although other emulated consoles may work. + +If your computer meets the general speed requirements +but games run too slowly, +try choosing a different +[audio driver](interface/higan-config.md#advanced), +since that's usually what drives higan's timing. + +On some computers, +the operating system's power-management system +may be confused by higan's unusual pattern of CPU usage +(it runs furiously to calculate the next video frame +and the next few milliseconds of audio, +then stops dead as it waits for output to complete). +If holding down +the [fast forward hotkey](interface/higan-config.md#hotkeys) +runs too fast but the game normally runs too slow, +try disabling "power saver" mode +or enabling "performance" mode. + +On Linux specifically, +if your desktop environment doesn't provide a way +to change the CPU usage governor, +you can temporarily force your CPUs to run at full-speed +by running the following command in a terminal: + + echo "performance" | sudo tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor + +To put things back to normal, +reboot the computer, or run this command instead: + + echo "ondemand" | sudo tee /sys/devices/system/cpu/cpu*/cpufreq/scaling_governor + Why is higan so much slower than other emulators? -------------------------------------------------