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The Bandwidths Window (Apple Silicon only)

To open the Bandwidths window, select the menu item Window > Show Bandwidths (Apple Silicon) or press the key combination ⌘ + 9.

The window can only be opened if you are using a Macintosh with Apple Silicon. It lists in a table which units of the Apple processor transferred how much data during measurement. Depending on the direction of data transmission, a distinction is made between read and write. Some data transfers also take into account that the data actually runs over the DRAM Command Scheduler. This is marked by DCS.

The DRAM Command Scheduler is a hardware component that optimizes access to the individual memory chips. The DCS takes into account the organization of RAM memory cells in rows and columns, the distribution of data onto individual chips, as well as their respective buffer memory during data transmission. Access is optimized by changing its order so that the latency of each operation is as small as possible.

The columns of the table present the following data:

The individual components of Apple processors keep their own statistics on the amount of data transferred.
The individual components of Apple processors keep their own statistics on the amount of data transferred.

The abbreviations for the individual components are defined by Apple and are not officially documented. The following table is for guidance only. The list does not claim to be complete and may be subject to change depending on processor generation.

Abbreviation Meaning
ANE Unit for Machine Learning (Apple Neural Engine)
ANS Main controller of the Apple System-on-a-Chip
ATCx Apple Tunable Controller x
DCS DRAM Command Scheduler
DCS CAS RAM Column Access Strobe
DCS RAS RAM Row Access Strobe
DISP Video display output
ECPU Efficiency cores
EXT DISPx Video display output for external port x
GFX GPU cores
GFXx GPU cores of cluster x
ISP Integrated signal processing
JPG JPEG data compression
PCIE LN PCI Express Lane
PCPU Performance cores
PCPUx Performance cores of cluster x
PRORES Apple ProRes video processing
STRM CODEC Compressor/decompressor for video data streams
VDEC Video decoder
VENC Video encoder