Storage

The following points/suggestions should be considered when running jobs concurrently:

Performance versus block size (read/write)

The following output shows the performance achievable, on SATA SSDs, for reads/writes of differing block sizes.

Block size 4K Write: 256000000 bytes (256 MB, 244 MiB) copied, 2.97716 s, 86.0 MB/s
Block size 4K Read : 256000000 bytes (256 MB, 244 MiB) copied, 2.54667 s, 101 MB/s
Block size 64K Write: 255983616 bytes (256 MB, 244 MiB) copied, 0.287594 s, 890 MB/s
Block size 64K Read : 255983616 bytes (256 MB, 244 MiB) copied, 0.248797 s, 1.0 GB/s

The story told by the brief output above is universal - small files move around at much slower rates than large files.