Some improvements to the audio section after review.

[nageru-docs] / hardware.rst

diff --git a/hardware.rst b/hardware.rst
index 8a2bb06f0e801e75a04643fe646f198fc0085641..9d157807c03a6ec7d7cdd56600b1085cbd5e894a 100644 (file)
--- a/hardware.rst
+++ b/hardware.rst
@@ -122,3 +122,20 @@ account for clock and jitter).
 Nageru works in 16-bit floating-point RGBA internally. High-quality conversion to and
 from subsampled Y'CbCr (typically 4:2:2 for inputs and 4:2:0 for outputs)
 is done transparently on the GPU.
+
+
+Performance tips
+----------------
+
+It is strongly recommended to have the rights to run at real-time priority;
+it will make the USB3 threads do so, which will make them a lot more stable.
+(A reasonable hack for testing is probably just to run it as root using sudo,
+although you might not want to do that in production, but instead grant
+your regular user permissions in /etc/security/limits.conf.) Note also that if you
+are running a desktop compositor, it will steal significant amounts of GPU
+performance. The same goes for PulseAudio.
+
+Nageru tries to lock itself into RAM if it has the permissions to do
+so, for better realtime behavior. (Writing the stream to disk tends to
+fill the buffer cache, eventually paging less-used parts of Nageru out.)
+Again, this is something you can set in limits.conf.