Sign in with
Sign up | Sign in
Your question
Solved

What is RAID 0 and AHCI and all that kind of things?

Last response: in Storage
Share
December 28, 2012 3:50:49 AM

Hey guys I am about to buy a Samsung 840 (NON PRO) series 120 GB SSD. And I have read people talking about RAID 0 and AHCI mode and all. Can someone tell me what that means? And what should I do with my SSD to get the best performance possible out of it? Thanks any kind of help would be appreciated. :D 

More about : raid ahci kind things

a b G Storage
December 28, 2012 4:10:00 AM

Without get too technical, I'll say they are only casually related. AHCI is the preferred interface for an SSD. RAID 0 is way of connecting two or more drives with advantages and disadvantage, but primary faster speeds. Since SSD's are inherently fast yet relatively new, many ask if it is faster or better than RAID0 with traditional drives, and can it be done with SSDs, will it support the SSD specific features.

The other time it is mention is during setup if one must choice between AHCI and RAID on a controller.
m
0
l
a c 544 G Storage
December 28, 2012 4:18:41 AM

SATA ports can have 3 settings (modes): IDE, AHCI, & RAID.

IDE mode is used mainly by optical drives (CD, DVD, Blu-ray, etc.).
SSDs need to be in AHCI mode for best performance.
RAID mode is used when you are combining 2 or more physical drives to create 1 logical drive (C: or D: drive for example).

You have only 1 SSD so don't worry about creating a RAID-0 array.
Just make sure the port you have the drive connected to is in AHCI mode before you install your O/S on it.
m
0
l
Related resources
December 28, 2012 4:33:39 AM

Dereck47 said:
SATA ports can have 3 settings (modes): IDE, AHCI, & RAID.

IDE mode is used mainly by optical drives (CD, DVD, Blu-ray, etc.).
SSDs need to be in AHCI mode for best performance.
RAID mode is used when you are combining 2 or more physical drives to create 1 logical drive (C: or D: drive for example).

You have only 1 SSD so don't worry about creating a RAID-0 array.
Just make sure the port you have the drive connected to is in AHCI mode before you install your O/S on it.


Thanks for replying man. I am gonna be using that ssd with a 5400 rpm(lol) old hdd. So how do you think I should set this whole thing up? I have the Msi z77a-GD65 Motherboard.
m
0
l
a c 89 G Storage
December 28, 2012 4:46:43 AM

catchme247 said:
Hey guys I am about to buy a Samsung 840 (NON PRO) series 120 GB SSD. And I have read people talking about RAID 0 and AHCI mode and all. Can someone tell me what that means? And what should I do with my SSD to get the best performance possible out of it? Thanks any kind of help would be appreciated. :D 


IDE mode (AKA Parallel ATA mode) is the "old" way of specifying the operation of Parallel ATA port controllers which are used to control hard drives (ATA devices) and optical disks (ATAPI devices). When Serial ATA devices are attached to a port controller that is running in IDE mode, the IDE specification is emulated. This is nice for compatibility purposes as it allows SATA drives to be transparently connected to an operating system or storage controller that does not natively support SATA.

AHCI is the "new" way of specifying the operation of Serial ATA port controllers which fully exposes the capabilities of newer devices such as BluRay drives, new Hard Drives, and SSDs. AHCI is fundamentally similar to IDE but is necessary to enable operations which are supported by the SATA specification but not by the PATA specification, such as hot swapping and advanced power management.

The controller should be left in AHCI mode whenever possible.

Now, on to "RAID". RAID is contextually sensitive. RAID means "Redundant Array of Individual/Inexpensive Disks". In short, this means taking more than one physical disk and combining them into a logical disk with different operational properties.

RAID-0 is known as "striping" which splits data across two or more disks in a striped fashion, allowing a single large file to be written to or read from two or more disks simultaneously, leveraging the IO capabilities of each disk in a combined fashion. Thus, a RAID-0 with two 1TB hard drives would have a volume size of 2TB and IO capabilities greater than that of one of the 1TB hard drives on its own.

RAID-1 is known as "mirroring" which writes the same data to two or more disks at the same time such that they are identical. Thus, if one drive suffers mechanical failure or disk degradation, the mirrored drive will be intact. As an added benefit, both disks can be read from independently for increased read performance.

There are other forms of RAID such as RAID-5 and RAID-10, but that's enough for now.

When RAID mode is enabled, it is enabled in a vendor specific fashion. On the Intel storage controller found on all Intel chipsets, enabling RAID (where supported) will also enable AHCI. If you want to boot from a combined volume, then this is the recommended approach. However, putting SSDs in RAID is not recommended as many features are not supported except on the newest chipsets.
m
0
l

Best solution

a c 544 G Storage
December 28, 2012 4:50:09 AM

catchme247 said:
So how do you think I should set this whole thing up? I have the Msi z77a-GD65 Motherboard.


1.) Connect your SSD to port SATA1.
2.) Change the SATA mode of ports SATA1 & SATA2 to AHCI.
3.) Install Windows.
4.) After Windows installation is complete shut down and connect your HDD to port SATA2.
Share
December 28, 2012 5:00:48 AM

Best answer selected by catchme247.
m
0
l
December 28, 2012 5:06:38 AM

Dereck47 said:
1.) Connect your SSD to port SATA1.
2.) Change the SATA mode of ports SATA1 & SATA2 to AHCI.
3.) Install Windows.
4.) After Windows installation is complete shut down and connect your HDD to port SATA2.


So, I dont have to worry about the RAID thingy right?
m
0
l
a b G Storage
December 28, 2012 5:12:54 AM

Right.
m
0
l
!