# AHCI vs RAID



## i1yas (Nov 9, 2014)

I have just bought a Asus P8H77 VLE SATA 6gbps in my previous MOBO Asus P8H61 MLX there were just two option under SATA control IDE and AHCI but in New Mobo there is one option RAID i have a SSD Kingston V300 120 GB which is SATA 6gbps and a 1 tb Seagate HDD dont know if is its SATA 2 or SATA 3 HDD. My Question is whar should i select here for Better Performance?AHCI or RAID?


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## FordGT90Concept (Nov 9, 2014)

Even if I never intend to set up a RAID, I still use it.  The drivers tend to be better and you can set up a RAID in the future without any changes to the OS.

AHCI is available option for legacy support (really old IDE drives).


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## i1yas (Nov 9, 2014)

You mean I should Select RAID?in Reality i select RAID but when PC boot there a windows Comes up and and in Green FONT i can saw NO RAID DRIVE..


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## FordGT90Concept (Nov 9, 2014)

Can you take a picture of this?  You can upload it to www.techpowerup.org

The RAID software should say it is a "non-RAID disk" and that's normal.  You shouldn't have to go into the RAID setup at all because you're not using a RAID.

Note: Changing this setting after an operating system is installed is inadvisable.


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## Solaris17 (Nov 9, 2014)

FordGT90Concept said:


> Even if I never intend to set up a RAID, I still use it.  The drivers tend to be better and you can set up a RAID in the future without any changes to the OS.
> 
> AHCI is available option for legacy support (really old IDE drives).



ugh AHCI is not for really old IDE drives. IDE is for really old IDE drives.

and RAID only expands on AHCI since by default RAID supports AHCI

http://en.wikipedia.org/wiki/Advanced_Host_Controller_Interface


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## FordGT90Concept (Nov 9, 2014)

Wikipedia said:
			
		

> Many SATA controllers offer selectable modes of operation: *legacy Parallel ATA emulation*, standard AHCI mode, or vendor-specific RAID (which generally enables AHCI in order to take advantage of its capabilities).


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## Solaris17 (Nov 9, 2014)

in systems that usually only offer enhanced AHCI or RAID configurations. Just because AHCI (As well as RAID) support IDE drives does not necessarily mean that is what they are for. and since RAID also supports IDE drives. your persistence to use it over AHCI 





FordGT90Concept said:


> AHCI is available option for legacy support (really old IDE drives).


 Still makes no sense.


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## newtekie1 (Nov 9, 2014)

FordGT90Concept said:


> Many SATA controllers offer selectable modes of operation: *legacy Parallel ATA emulation*, standard AHCI mode, or vendor-specific RAID (which generally enables AHCI in order to take advantage of its capabilities).



The bold section is the "IDE" mode on most motherboards, not AHCI.  AHCI's purpose is entirely for SATA operation.  It is what is responsible for the extra features of SATA such as hot swapping and NCQ as well as TRIM support.

RAID mode on the other hand activates the chipsets firmware RAID.  If you aren't actually going to set up a RAID array there isn't much point in enabling RAID mode.  In fact it can actually be limiting in some ways, such as TRIM not working properly on SSDs(big issue with AMD, newer Intel chipsets now allow trim through RAID and Intel actually managed this by making their firmware RAID somewhat AHCI compatible).

Answer to OP's Question:
If you don't plan setup RAID, leave it set to AHCI.  The reason it pops up in green saying No RAID Drives is exactly that, you don't have any RAID arrays in the system and no drives in the system capable of making a RAID array.  You need at least two, somewhat similar drives in the system to make a RAID array.  A 128GB SSD and a 1TB HDD are not similar enough to create a RAID array.  So Intel's firmware RAID is smart enough to not even let you try and just gives you the message.


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## Jetster (Nov 9, 2014)

AHCI,  RAID is AHCI but requires more than one drive


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## FordGT90Concept (Nov 9, 2014)

newtekie1 said:


> If you don't plan setup RAID, leave it set to AHCI.  The reason it pops up in green saying No RAID Drives is exactly that, you don't have any RAID arrays in the system and no drives in the system capable of making a RAID array.


You may be right but not for the reason given.  When RAID is enabled, the controller gets a boot device in the BIOS but if you don't go into the RAID config and set a boot device, the BIOS doesn't know what to run when it is told to boot.  This can lead to the error.  The solution would be to go into the RAID config and set the appropriate drive as bootable then set the BIOS to boot to the RAID controller.

Alternatively, the drives may show up individually in the BIOS if they aren't explicitly added to a RAID.  Make sure you select the appropriate drive from the RAID list if that is the case.


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## MxPhenom 216 (Nov 9, 2014)

Simple answer:

Set to AHCI if you aren't planning to run a RAID array. Set to RAID mode if you are running a RAID array (RAID 0,1,5,10)



FordGT90Concept said:


> You may be right but not for the reason given.  When RAID is enabled, the controller gets a boot device in the BIOS but if you don't go into the RAID config and set a boot device, the BIOS doesn't know what to run when it is told to boot.  This can lead to the error.  The solution would be to go into the RAID config and set the appropriate drive as bootable then set the BIOS to boot to the RAID controller.
> 
> Alternatively, the drives may show up individually in the BIOS if they aren't explicitly added to a RAID.  Make sure you select the appropriate drive from the RAID list if that is the case.



You are making it more difficult than it needs to be. Not to mentioned trying to argue over correct information....


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## Aquinus (Nov 9, 2014)

I would just set it to AHCI. That's the most simple way to go. Intel RAID software for drive management still works in AHCI mode so this really is a non-issue. RAID should be used if you plan on using RAID, it's really that simple.


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## newtekie1 (Nov 9, 2014)

FordGT90Concept said:


> You may be right but not for the reason given. When RAID is enabled, the controller gets a boot device in the BIOS but if you don't go into the RAID config and set a boot device, the BIOS doesn't know what to run when it is told to boot. This can lead to the error. The solution would be to go into the RAID config and set the appropriate drive as bootable then set the BIOS to boot to the RAID controller.
> 
> Alternatively, the drives may show up individually in the BIOS if they aren't explicitly added to a RAID. Make sure you select the appropriate drive from the RAID list if that is the case.



With Intel RAID, at least on all the recent Chipsets I've used(P55, P67, Z68, Z87, Z97), everything connected to the Intel RAID is visible in the BIOS.  Multiple RAID arrays appear in the BIOS.  So if you create Array_00, Array_01, and Array_02 and have a single lone drive connected all 4 devices will show up in the BIOS just like they are standard hard drives.  You pick the boot device in the standard BIOS just like picking a boot drive normally.

What you are describing is usually the process when you are using a 3rd party controller.


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## Aquinus (Nov 10, 2014)

newtekie1 said:


> With Intel RAID, at least on all the recent Chipsets I've used(P55, P67, Z68, Z87, Z97), everything connected to the Intel RAID is visible in the BIOS.  Multiple RAID arrays appear in the BIOS.  So if you create Array_00, Array_01, and Array_02 and have a single lone drive connected all 4 devices will show up in the BIOS just like they are standard hard drives.  You pick the boot device in the standard BIOS just like picking a boot drive normally.
> 
> What you are describing is usually the process when you are using a 3rd party controller.


True, however the controller itself will still the the RAID controller driver as opposed to the AHCI driver. The biggest benefit in my personal opinion is that if you don't have chipset drivers installed and it's set to AHCI, it's almost certain to pick up the generic Microsoft AHCI drivers where with RAID, it very well might not detect the chipset RAID driver OOTB.

For simplicity sake, I still think using AHCI is a better idea if you don't need RAID. I see no benefit of running RAID without having a RAID array.


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## Mussels (Nov 10, 2014)

IDE is the old compatible mode, AHCI is the newer SATA2/SSD compatible mode, and RAID is designed for multiple drives working together.

Depending on your controller, you MAY lose some features running the RAID mode, so i highly recommend AHCI.

For example, on some chipsets running RAID meant TRIM would stop working, which negatively affected SSD performance.

AHCI is the 'safe' and reliable option if you don't plan to run RAID any time soon.


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## VulkanBros (Nov 10, 2014)

Yes - but RAID is a great alternative if you are running with "old fashion harddrives".... RAID 0 can really speed things up,
(on the cost of secureness in a drive fault situation)


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## Mindweaver (Nov 10, 2014)

Always use RAID or AHCI on any SATA drives. Remember, using IDE compatibility mode limits the drive to UDMA 133 speeds 133 MB/s which is close to SATA1 1.5 Gbit/s - 150 MB/s. Which is why most people don't bother with AHCI or RAID for the small gain, but I would.. 

*Hard Drive speeds*

IDE Ultra ATA/33 = .3Gbit/s - 33 MB/s
IDE Ultra ATA/66 = .6Gbit/s - 66 MB/s
IDE Ultra ATA/100 = 1Gbit/s - 100 MB/s
IDE Ultra ATA/133 = 1.3Gbit/s - 133 MB/s
SATA1 = 1.5 Gbit/s - 150 MB/s
SATA2 = 3 Gbit/s - 300 MB/s
SATA 3 = 6 Gbit/s - 600 MB/s
*EDIT: Forgot to add that for a single drive I would use AHCI driver over a RAID drive for no other reason than to boot up quicker. Enabling RAID will check your RAID array on startup and give you a chance to change or create a RAID array.*


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## i1yas (Nov 10, 2014)

I have selected Raid and installed windows 7.but Now i m getting 80% performance of my SSD and getting this on HD sentinel " the trim feature of the ssd is supported but disabled " like in picture bellow

http://i.imgur.com/9GThiiQ.png
what should i do to get 100% performance?


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## MxPhenom 216 (Nov 10, 2014)

i1yas said:


> I have selected Raid and installed windows 7.but Now i m getting 80% performance of my SSD and getting this on HD sentinel " the trim feature of the ssd is supported but disabled " like in picture bellow
> 
> http://i.imgur.com/9GThiiQ.png
> what should i do to get 100% performance?



Why did you choose RAID? Doesn't look like you are running a RAID array. 

and TRIM is probably disabled because I do not think your chipset supports TRIM with RAID setting.


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## i1yas (Nov 10, 2014)

MxPhenom 216 said:


> Why did you choose RAID? Doesn't look like you are running a RAID array.
> 
> and TRIM is probably disabled because I do not think your chipset supports TRIM with RAID setting.


I selected this Before posting this thread i have Asus p8H77 V LE i don't know if its supports trim with Raid or not..but need help to get 100% performance.


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## Aquinus (Nov 10, 2014)

VulkanBros said:


> Yes - but RAID is a great alternative if you are running with "old fashion harddrives".... RAID 0 can really speed things up,
> (on the cost of secureness in a drive fault situation)


You gain bandwidth at the expense of IOPS. Seek latency goes up when you use RAID as all drives needs to get to the same sector and could take different amounts of time to get there. I strongly believe if you need performance SSD is the way to go. If you need mass storage, you're most likely going to want to keep your stuff safe and will tend to read data more than write it, in which case RAID-5 is superior across the board as you gain redundancy and read performance at the expense of disk space (you get N - 1 drives worth of space) and write performance (as parity blocks must be calculated and written).

However I've now been side-tracked... Just go with AHCI. You can always switch to RAID down the road if you even end up caring about such things.

Side note: TRIM being issued to SSDs with the RAID driver depends on the version of RST (or RSTe in my case) as a newer (and unsupported version for X79) was required before I gained TRIM though my RAID. Another way to keep this simple is... using AHCI.


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## EarthDog (Nov 10, 2014)

AHCI. While using RAID wont hurt anything, it wont help anything either unless you are actually going to use RAID... but as Aquinas said you can just switch to it without any issues (outside of building your array of course). It was also mentioned that using RAID without an array can increase boot times as it looks for an array.

TRIM has worked in RAID for quite a while now, again as Aquinas said, so long as you have the latest driver (though I recall it being in the chipset/INF/RAID ROM and not the rapid storage drivers??). Update em both.


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## newtekie1 (Nov 10, 2014)

Where are you getting the 80% number from?


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## Aquinus (Nov 10, 2014)

EarthDog said:


> TRIM has worked in RAID for quite a while now, again as Aquinas said, so long as you have the latest driver (though I recall it being in the chipset/INF/RAID ROM and not the rapid storage drivers??). Update em both.


For my case, the latest X79 chipset RAID driver stopped at version 3.6.x.x. TRIM in RAID was added to RSTe in 3.7.0.0 and the latest version for C600 series chipsets is 2.8.0.x last time I checked which was a year ago. I forced installation of the newer RSTe driver to get it to work. It's also why my RAID driver says C600+/C220+ instead of X79. I had to get creative.


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## i1yas (Nov 11, 2014)

Can i run existing windows 7 with AHCI sata setting?i have installed windows with Raid when i boot windows changing from raid to ahci it goes to blue screen error for eye blink time and restart again.is  there any method?


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## Darcy (Nov 11, 2014)

Reid is a good choice,believe me,i have used that for a long time.



Sony Xperia Z3 Hülle


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## MxPhenom 216 (Nov 11, 2014)

Darcy said:


> Reid is a good choice,believe me,i have used that for a long time.



What's Reid?


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## i1yas (Nov 11, 2014)

Darcy said:


> Reid is a good choice,believe me,i have used that for a long time.


May be you are right its latest than AHCI so it will be good may be.


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## Mussels (Nov 11, 2014)

i1yas said:


> I have selected Raid and installed windows 7.but Now i m getting 80% performance of my SSD and getting this on HD sentinel " the trim feature of the ssd is supported but disabled " like in picture bellow
> 
> http://i.imgur.com/9GThiiQ.png
> what should i do to get 100% performance?




AHCI will get TRIM working. As i said earlier, not many RAID controllers support TRIM.


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## MxPhenom 216 (Nov 11, 2014)

i1yas said:


> May be you are right its latest than AHCI so it will be good may be.



Thats not really true. The difference between RAID and AHCI is that with the RAID setting it initializes the RAID controller so you can setup arrays with multiple, but similar or identical drives, where as AHCI is just for single disks that dont need to be in a RAID array. They are both AHCI, but RAID has some extra "features."


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