By default, hashcat only uses GPUs when available. You can modify that with these flags.
Code:
$ hashcat --help | grep opencl-device
-d, --opencl-devices | Str | OpenCL devices to use, separated with commas | -d 1
-D, --opencl-device-types | Str | OpenCL device-types to use, separated with commas | -D 1
$ hashcat --help | grep -A 4 Device
- [ OpenCL Device Types ] -
# | Device Type
===+=============
1 | CPU
2 | GPU
3 | FPGA, DSP, Co-Processor
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