Performance Specifications

Performance Specifications (Atlas 200/300/500 Inference Product)

• The recommendations on channel count in typical single-device VDEC scenarios are as follows.

  Table 1 Performance specifications of the Ascend AI Processor on the Atlas 200/300/500 Inference Product

  Resolution	Total Frame Rate	Per Channel Frame Rate (n Channels)	Max Memory Usage per Channel (Using H.265 Input Streams with Nine Reference Frames as an Example)
  4K	120 FPS	120 FPS/n (n = 4 is recommended, 30 FPS per channel.)	About 182 MB
  1080p	480 FPS	480 FPS/n (n = 16 is recommended, 30 FPS per channel.)	About 56 MB
  ≤ 720p	960 FPS	960 FPS/n (n = 32 is recommended, 30 FPS per channel.)	About 35 MB

  The following table uses 1080p input streams as an example to describe the formula for calculating the maximum memory used by each VDEC channel. The memory usage is calculated as follows:

  • Buffer size for the input streams: 6 MB when resolution ≤ 1080p; 9 MB when resolution > 1080p.
  • Frame buffer size for the decoded images: 3 MB when resolution = 1080p. For other resolutions, convert the value proportionally.
  • TMV buffer size for the decoded images: 0.5 MB for H.264 1080p input streams; 1 MB for H.265 1080p input streams. For other resolutions, convert the value proportionally.
  • Number of reference frames: The maximum number of reference frames is used as an example. The system adapts to the actual number.

  Formula	Scenario	Memory Usage
  4 MB + Buffer size for the input streams x 2 + (Frame buffer size for the decoded images + TMV buffer size for the decoded images) x (Number of reference frames + 1)	Input stream format: H.264 Input stream resolution: 1080p Buffer size for the input streams: 6 MB Frame buffer size for the decoded images: 3 MB TMV buffer size for the decoded images: 0.5 MB	51 MB (nine reference frames) 26.5 MB (two reference frames)
  	Input stream format: H.265 Input stream resolution: 1080p Buffer size for the input streams: 6 MB Frame buffer size for the decoded images: 3 MB TMV buffer size for the decoded images: 1 MB	56 MB (nine reference frames) 28 MB (two reference frames)

• Suggestions on the number of decoding channels and frame rate:

  The specifications in the following table are for reference only. If the number of channels started per process exceeds these listed specifications, memory insufficiency or performance drop may occur, leading to decoding channel creation failures or slow decoding.

  720p indicates a resolution of 1280 x 720 pixels. 1080p indicates a resolution of 1920 x 1080 pixels. 4K indicates a resolution of 3840 x 2160 pixels.

  Typical Resolution	Suggested Channel Count per Process (Based on the Input Frame Rate)
  -	Input frame rate ≥ 25 FPS	20 FPS < Input frame rate < 25 FPS	15 FPS < Input frame rate ≤ 20 FPS	10 FPS < Input frame rate ≤ 15 FPS	Input frame rate ≤ 10 FPS
  ≤ 720p	32 channels	32 channels	32 channels	32 channels	32 channels
  1080p	16 channels	19 channels	24 channels	32 channels	32 channels
  4K	4 channels	4 channels	6 channels	8 channels	12 channels

Performance Specifications (Atlas Training Series Product)