Various tweaks, including introductions from the README.

[nageru-docs] / hardware.rst

diff --git a/hardware.rst b/hardware.rst
index 9d6af9d5cd0c41173a9f42d432d46c9191a0de8d..9d157807c03a6ec7d7cdd56600b1085cbd5e894a 100644 (file)
--- a/hardware.rst
+++ b/hardware.rst
@@ -116,9 +116,26 @@ interlaced input, Nageru will automatically deinterlace for you.
 Frame rates are automatically converted; one input is designated as the
 **master clock** (right-click on an input to select it as such), and gets
 to dictate the frame rate of the output. Inputs with differing frame rates
-will get frames duplicated or dropped as needed (with adaptive queueing to
+will get frames duplicated or dropped as needed (with adaptive queuing to
 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.