why my blur lags my video?

[torpid sparrow]

• blur
  blur: true
  blur amount: 1
  blur output fps: 60
  blur weighting: gaussian_sym

• interpolation
  interpolate: true
  interpolated fps: 3

• rendering
  quality: 18
  preview: false
  detailed filenames: true

• timescale
  input timescale: 1
  output timescale: 1
  adjust timescaled audio pitch: false

• filters
  brightness: 1
  saturation: 1.2
  contrast: 1.1

• advanced rendering
  gpu: false
  gpu type (nvidia/amd/intel): amd
  deduplicate: true
  custom ffmpeg filters: -c:v h264_amf -quality quality -qp_i 16 -qp_p 18 -qp_b 22

• advanced blur
  blur weighting gaussian std dev: 2
  blur weighting triangle reverse: false
  blur weighting bound: [0,2]

• advanced interpolation
  interpolation program (svp/rife/rife-ncnn): svp
  interpolation speed: medium
  interpolation tuning: default
  interpolation algorithm: 23

[torpid sparrow]

thx