Question: I am seeing only 50MB/s reads:

```
ensnare@box:~$ sudo hdparm -tT /dev/sda
[sudo] password for ensnare:

/dev/sda:
 Timing cached reads:   4592 MB in  2.00 seconds = 2296.48 MB/sec
 Timing buffered disk reads:  192 MB in  3.90 seconds =  49.24 MB/sec

```

The array is already rebuilt and operational. Is this kind of slow performance normal? Anything I can do to make it faster? There weren't too many options in the controller configuration. Thanks.

Answer: 
Please take a look at the following info:

The default cache policy on a physical disk is Enabled in SATA drives and Disabled on SAS drives. When physical disk caching is Enabled, disk I/O performance is improved, but a power outage or equipment failure might result in data loss or corruption. 

NOTE: It is recommended that you use a backup power source for all Dell production systems. 

On a PERC H200 card, caching is forced to be disabled for all physical disks configured into a virtual disk, regardless of the drive type and default drive settings.”

<http://support.dell.com/support/edocs/storage/storlink/h200/en/ug/html/features.htm>
Here's THE best solution if going to a H700 isnt possible.
Enable cache directly from the firmware. YOU MUST be running on a battery backup or if power goes out you could be hosed by enabling the cache. Below is a tutorial explaining the full process to do so.

<http://www.1337admin.org/windows-server/windows-server-2012-r2/dell-h200-raid-controller-speed-hack/>