examples: Change benchmark_rate default thread priority

This commit modifies the benchmark_rate example to use the operating
system's default thread priority, instead of real-time thread priority,
by default. UHD 4.0 includes a number of significant improvements to
the streaming architecture that allow for best performance to be
achieved without having to resort to elevating the process thread
priority to real-time. Internal testing shows degraded streaming
performance in common use cases (i.e. non-DPDK) when the process thread
priority is set to real-time.

It should be noted that applications which use DPDK may still experience
better performance when the process thread priority is set to real-time.
Users may continue to manually override the process thread priority
in benchmark_rate using the --priority=high command-line option. The
need to elevate the process thread priority will be application- and
deployment-dependent.

1 files changed, 1 insertions, 1 deletions

diff --git a/host/examples/benchmark_rate.cpp b/host/examples/benchmark_rate.cpp
index 3db5b88a0..673649ddb 100644
--- a/host/examples/benchmark_rate.cpp
+++ b/host/examples/benchmark_rate.cpp
@@ -371,7 +371,7 @@ int UHD_SAFE_MAIN(int argc, char* argv[])
         // NOTE: TX delay defaults to 0.25 seconds to allow the buffer on the device to fill completely
         ("tx_delay", po::value<double>(&tx_delay)->default_value(0.25), "delay before starting TX in seconds")
         ("rx_delay", po::value<double>(&rx_delay)->default_value(0.05), "delay before starting RX in seconds")
-        ("priority", po::value<std::string>(&priority)->default_value("high"), "thread priority (high, normal)")
+        ("priority", po::value<std::string>(&priority)->default_value("normal"), "thread priority (normal, high)")
     ;
     // clang-format on
     po::variables_map vm;