Internal Raid Controller - EVGA Z370 MICRO User Manual

EVGA Z370 MICRO (121-KS-E375)

Internal RAID Controller

This section introduces RAID, RAID levels, and the basics of the controller integrated
into the PCH. It covers the basics of what RAID does, how RAID works, and why you
may or may not want to use RAID.
This section is GREATLY simplified; those who have experience with RAID -
especially from the server side - will find this a VERY rudimentary simplification of a
process that is quite complex on the back-end. The descriptions of the RAID levels are
not based on the back-end logic from the controllers, but rather just a breakdown as a
visual reference to understand the basics.
For the sake of explanation in this section, every drive representation here is assumed to
be 1 Terabyte (for ease of math); also the reference of P-Drive is "Physical" drive, and
L-Drive is referencing "Logical" drives; physical drives are the physical drive you
installed, whereas the logical drive is what Windows sees in Disk Management. This is a
necessary distinction because RAID is a form of drive virtualization; taking several
physical drives and making one logical drive out of them. You can add a minimum of
two drives up to a maximum of six drives depending on the configuration (for this
controller specifically) and the operating system will see only one logical device.
RAID LEVELS
ALL RAID LEVELS: All RAID levels will lose some capacity through the process of
making the array. A small amount of disk space is used, in part, to maintain connections
to data across drives, but the quality and size of drives used can impact the amount.
A general rule of thumb for final array capacity is this: Take the number of drives, the
array type, and individual drive capacity (for this RAID breakdown all drives are 1TB)
and multiply it out as shown below for the specific RAID type you intend to use:
RAID0 = (Number of Drives) * (Drive capacity)
RAID1 = Capacity of one drive, as all data is copied on both drives
RAID5 = (Number of drives – one drive) * (Drive capacity)
RAID10 = (Half the number of drives) * (Drive capacity)
To account for capacity lost both due to maintaining the array as well as what is lost
during the formatting process, multiply the product by .85 and you should see a volume
close to this number once the array is partitioned. This will vary based on type of drive,
- 50 -