low gpu utilization

[vale123]

I have 4 nvidia gpus performing a mask attack on a blockchain wallet. The gpu utilization is at 20% on each. 

I have tried using the different workload settings (-w 4, -O) but these have no effect.  The benchmark performs at 100% utilization. 

I am also unable to overclock, tune fan speeds, etc. with my gpu tuner utility (tried --gpu-temp-disable etc). 

What could be causing this? I saw some posts saying their utilization was low but on a dictionary attack. I am using pci-usb risers for the cards. I have the latest nvidia graphics drivers. Running on windows 10. Could there be problems with openCL drivers?

[Chick3nman]

What is your mask? It sounds like that could be the issue since it's possible its a super small keyspace.

[vale123]

What is your mask? It sounds like that could be the issue since it's possible its a super small keyspace.

Currently trying 10 characters:
?l?u?d!@#,?d!@#$,?u?l?l?l?l?l?l?1?2?2

also tried similar 6 and 8 character versions.

[Skwerl23]

What is your mask? It sounds like that could be the issue since it's possible its a super small keyspace.

Currently trying 10 characters:
?l?u?d!@#,?d!@#$,?u?l?l?l?l?l?l?1?2?2

also tried similar 6 and 8 character versions.

from what i've seen it's hard to break 60% of the speeds capable. Can you give the entire command you're using? And can you show the status output during the attack?