Rebalance disk write throttle

Greetings all,

I installed a new SSD into a test cluster (5 SDS servers on RHEL, each with 10G NICs and 2 SSDs on SATA-6 controllers), and ScaleIO immediately started to rebalance the data in the cluster.  However, I noticed the new disk is only about 65% busy during the rebalance activity (about 365MB/sec writes), and the other SSD drives are hitting about 180MB/sec reads.  There is little to no activity from the clients mounting the devices exported by ScaleIO.  Both the Rebuild Policy and Rebalance Policy are set to none in the ScaleIO Manager GUI under "Set I/O Priority".

Since I have disabled any/all throttling options in the ScaleIO Manager GUI, so I would expect the newly inserted drive to hit 500MB/sec easily.  I have also tuned each server according to the ScaleIO performance tuning guide.  Yet, it seems there is some arbitrary write cap of about 375MB/sec per drive.

Are there any other options I can look at to get maximum performance (both reads/writes) from the SSDs?  Anything at the Operating System level or any SDS tuning options?

Let me know if you need more detailed information from the test setup.