# Amazon DCV server imaging Counters in this set provide information about the subsystems responsible for screen grabbing, encoding and delivery. Counters in this set are divided in two groups: + For those in the first group, Amazon DCV collects one value for each session and publishes it in the `$session_name` instance. + For those in the second group, Amazon DCV collects one value for each encoder in each session. There are three active encoders: + one full-frame encoder + one tile-based encoder + one lossless encoder These counters are published in the `$session_name:$encoder_name` instances. | Counter name | Description | Unit | Instance | | --- | --- | --- | --- | | Grabbed Frames/sec | Captured frame rate in frames per second | Count/second | session | | Grabbed Frames | Total number of captured frames since the session started | Count | session | | Sent Frames/sec | Rate of screen frames sent per second to the connected client | Count/second | session | | Dropped Frames/sec | Rate of screen frames that were not sent to the connected client per second | Count/second | session | | Display Latency ms | Average time in milliseconds between frame capture and presentation | Milliseconds | session | | Available Bandwidth bits/sec | Estimated bandwidth available in the connection, in bits per second | Bits/second | session | | Encoded Frames/sec | Rate of screen frames encoded per second | Count/second | session:encoder | | Encoding Time ms | Average time, in milliseconds, used for encoding one sceeen frame | Milliseconds | session:encoder | | Encoding Time per Megapixel ms | Average time, in milliseconds, used to encode one million pixels | Milliseconds | session:encoder | | Frame Quality % | Average frame compression quality, expressed as a percentage | Percent | session:encoder | | Frame Compression Ratio % | Average frame compression ratio, defined as the ratio between the frame size, in bytes, and the size of the compressed frame | Percent | session:encoder |