What are the *_realtime variants of metrics?

Hello,

I was querying metrics from nv-nsight-cu-cli and found that some metrics have “_realtime” suffixes. Since neither the metrics guide and metrics decoder mentions this, I was wondering what is the difference between, for example, sm__warps_active_realtime.sum and sm__warps_active_realtime.avg and sm__warps_active.avg ?

Thanks in advance.

The “_realtime” counter variants are version of the GPU counters optimized to be collected in a single pass (no replay). These counters sometimes have reduced accuracy (off by ± 63). The Nsight Graphics GPU Trace tool makes heavy use of the “_realtime” counters allowing the tool to capture 2-6x more counters in each pass.