# cat /sys/kernel/debug/dri/64/radeon_pm_info
uvd    vclk: 0 dclk: 0
power level 0    sclk: 37500 mclk: 150000 vddc: 950 vddci: 875 pcie gen: 3

I'd like to know what are these vclk, dclk, sclk, mclk, vddc, vddci numbers. I guess vddc and vddci are some kind of frequencies in MHz (not sure memory or card), but I really would like to decypher this.

  • VCLK and DCLK are two UVD internal clocks.
  • SCLK is the Engine clock and MCLK is the Memory clock, both depend on the current power level.
  • VDDC (mV) is the GPU core voltage
  • VDDCI (mV) is the I/O bus voltage (between memory and GPU core) and comes from the PCI-Express slot.

Note: clock units seem to be kHz * 10 (Source)


  • I read the documentation you provided, but couldn't figure out what is an unit in sclk? sclk 37500 means 375MHz? and mclk 150000 means 1.5GHz? Jan 5 '15 at 16:51
  • @MladenAdamovic: Units for clock variables are a bit weird. It's kHz * 10. I've found this code which also applies the *10 factor. Jan 5 '15 at 16:57

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