Looks like performance of 30901 (Bitcoin raw private key (P2PKH), compressed) is limited by CPU, not GPU

[Konard]

hashcat -a 3 -m 30901 13zb1hQbWVsc2S7ZTZnP2G4undNNpdh5so "000000000000000000000000000000000000000000000002000000?h?h?h?h?h?h?h?h?h?h" -d 2

When I use this command with 30901 (Bitcoin raw private key (P2PKH), compressed) it looks like it gives me only 8000-9000 kH/s, and if I see at top

Then only 1 CPU core is used by hashcat. May it be a limiting factor for the performance? Is there a way to use more CPUs for data exchange with GPU?

Also for some reason OpenCL gives better performance then CUDA, should I create another issue for that?