Stopped and ran the I/O performance analsys thingy:

Code:
I/O Performance Analysis:

Note that this may take a while depending on your hardware configuration.

Working Memory:      179 GB
Swap-file Size:      358 GB
Min I/O Size:       32.0 MB
Computation Threads:    32

Sequential Write:          852 MB/s
Sequential Read:          1.74 GB/s
Threshold Strided Write:   489 MB/s
Threshold Strided Read:    498 MB/s

Overlapped VST-I/O Ratio: 0.5933

Notes:

  - The overall I/O speed is unable to keep up with the CPU(s).
    The I/O throughput is 1.68549x slower than the CPU throughput.
    Large computations will be significantly slowed down by disk access.
    I/O bandwidth can be increased in a number of ways:
      - Add more drives in parallel. This is the obvious way.
        Many machines have 4 or more drives just to run this program!
      - Defragment the drives.
      - Use empty drives. Empty and freshly formatted drives perform best.

  - Your threshold non-sequential I/O bandwidth is very high.
    This may cause sub-optimal algorithm selection for large computations.
    The optimal ratio between sequential/non-sequential I/O is about 3 to 1.
    It is recommended to decrease the "Min I/O Size" setting and re-run
    this benchmark.

  - Your write bandwidth is significantly lower than your read bandwidth.
    It is recommended to examine your storage configuration if you are
    expecting balanced read/write speeds.

Press ENTER to continue . . .
These values don't seem bad?