Shad-o-Box 1K/2K HS User Manual
p. 13
time system response to the detector transfer) then the moderation rate should be set to “maximum” by manually
adjusting the NIC parameter.
In the end, this is a compromise:
1. Enable interrupt moderation to minimize CPU usage, at the expense of a slight increase in latency
(
recommended
).
2. Disable interrupt moderation to favor responsiveness of real-time system with a drawback in CPU usage.
In most situations, extra latency introduced by interrupt moderation is very low and thus the gain on CPU
performance becomes more beneficial.
Receive Buffers
Under certain conditions the host PC system CPU may be busy with tasks other than the imaging application.
Incoming image packets remain in the PC memory allocated to store packets instead of immediately being copied
into the image buffer. By increasing the number of NIC (network interface card) receive buffers, more incoming
image packets can be stored by the NIC before it must start discarding them. This provides more time for the PC to
switch tasks and move image packets to the image buffer.
Not all network boards allow increases to their receive buffer count. Among those that do, different versions will
have different maximum receive descriptor values.
We recommend increasing the receive buffer size to the maximum permitted by the network card, in order to
provide more buffering capacity when needed.
