AeroSpark read performance

I am using latest AeroSpark connector to work with Spark ML. But when i have inserted round 60M records to AeroSpike, i got too big time amount in read operations. For example for fetch round 500K records from set that contains 60M records, AeroSpark spend ~30 mins. When i look at htop cmd output, AeroSpike use only 7% of CPU.

How can i speed up performance in read operations? Seems AeroSpark is working only by one thread, how i can parallelize this job? Any suggestions?

AeroSpike conf: memory-size 8G # Maximum memory allocation for data and
default-ttl 30d

storage-engine device {             # Configure the storage-engine to use                                                                                                                                       
    file /vol/             # Location of data file on server.                                                                                                                                          
    filesize 900G                   # Max size of each file in GiB.