# RAID vs AHCI mode



## Derek12 (Jan 12, 2010)

Hi.
I have a GA-MA74GM-S2H mobo, and a Seagate SATAII 150 GB Hard disk and I have installed Windows 7 ultimate 64 bit. I have enabled the AHCI mode for the SATA ports on BIOS
I am wondering if RAID mode is better than AHCI mode, though I have only one disk.

I enabled it anyway and Windows 7 refuses to boot (it restarts continously before the desktop is reached), I reverted to AHCI and it runs fine again.
Many thanks


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## mikek75 (Jan 12, 2010)

RAID stands for Random Array of Inexpensive Disks, since you don't have an array but a single disc I'm not surprised it won't boot! Sorry, just stick with AHCI if thats working for you.

Welcome to TPU BTW!


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## DRDNA (Jan 12, 2010)

but if you did indeed have two drives or more then raid0 is faster by far.


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## gvblake22 (Jan 12, 2010)

That is a setting that can only be changed when you are installing the operating system.  If you try and change it afterward you have to enable/install a different storage driver or reinstall the operating system with AHCI or RAID enabled.


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## computertechy (Jan 12, 2010)

is AHCI faster than IDE?

i have always wondered about this setting, sorry to ask a question on Ur thread buddy 

i have had problem with setting it to AHCI though, it wont boot. but if i set it to AHCI and do a new install of windows i start having problems. 

EDIT: NOT TO WORRY I FOUND A THREAD


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## Deleted member 3 (Jan 12, 2010)

mikek75 said:


> RAID stands for Random Array of Inexpensive Disks, since you don't have an array but a single disc I'm not surprised it won't boot! Sorry, just stick with AHCI if thats working for you.
> 
> Welcome to TPU BTW!



Yes, it's random. Sometimes they make them out inexpensive hard disks, some times in expensive stone disks found on the beach. Though they really have to be disk shaped (not just rocks). I once made a RAID array of random phaistos disks, I have no clue what those are, I googled it. Point is, it's all random.


Or perhaps it means Redundant instead.


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## mikek75 (Jan 12, 2010)

Oh you awkward sod, yeah, you' got me. Redundant.


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## driver66 (Jan 12, 2010)

mikek75 said:


> Oh you awkward sod, yeah, you' got me. Redundant.



ROFL   Dan strikes again


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## VulkanBros (Jan 12, 2010)

eehhh ... RAID is "Redundant Array of Independent Disks"......


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## mikek75 (Jan 12, 2010)

God, theres always one.... It can be EITHER!

http://www.webopedia.com/TERM/r/RAID.html

At least Dan had a point....


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## department76 (Jan 12, 2010)

i chuckled at that one, i learned in school years ago: redundant array of independent drives


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## mikek75 (Jan 12, 2010)

As the link I posted shows, it can be either, I learnt the original (albeit I mixed up the Random and Redundant bit).

The term was first coined when larger drives were very expensive, so the idea was to chain together a number of cheaper, smaller drives to achieve the effect.


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## department76 (Jan 12, 2010)

JBOD:  just a bunch of drives

that one sounds funny, but is actually correct lol


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## mikek75 (Jan 12, 2010)

Have you bothered to read that link I posted? Or are you going to keep on being a smart arse?
Don't you think Dan would have picked me up on it if it was wrong?

http://acronyms.thefreedictionary.com/Redundant+array+of+inexpensive+disks

http://www.howtoforge.com/redundant-array-of-inexpensive-disks-raid-technical-paper

http://www.cs.cmu.edu/~garth/RAIDpaper/Patterson88.pdf


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## gvblake22 (Jan 12, 2010)

Back on topic maybe?
The OP isn't asking what RAID stands for, they want to know what BIOS setting should be used and when.


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## VulkanBros (Jan 12, 2010)

Derek12 said:


> Hi.
> I have a GA-MA74GM-S2H mobo, and a Seagate SATAII 150 GB Hard disk and I have installed Windows 7 ultimate 64 bit. I have enabled the AHCI mode for the SATA ports on BIOS
> I am wondering if RAID mode is better than AHCI mode, though I have only one disk.
> 
> ...



I had the same problem, back when I was running with single disks.
On my Win7 64 bit I had to disable AHCI when installing...afterwards I then could enable AHCI mode again and the OS was running fine...I don´t know what the course is....

A little note: RAID0 is faster than AHCI when running - BUT...the boot-up time on a RAID
system is much slower due to the RAID controllers initializing of the disks/arrays.


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## Derek12 (Jan 13, 2010)

Hello, first, sorry for the late reply 
Many thanks to all!
Then If I don't have more than one disk, the RAID mode is useless and should I use the AHCI? And if in the future I want to add another disk, then should I enable RAID mode and reinstall Windows?
And yeah the bootup time is faar slower because the mobo have to initialize the controller ... :-(and it used a RAID0/JBOD mode...


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## Mussels (Jan 13, 2010)

IDE = the old standard
AHCI = IDE + NCQ and hotswap support
RAID = same as AHCI, but the ability to use RAID modes.


If you change a drive in/out of RAID, it has to be formatted. So yes, you have to reinstall windows if you use RAID at a later date. You do NOT need RAID to have multiple drives.


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## InnocentCriminal (Jan 13, 2010)

mikek75 was right with _Random_ array it is either.

Anyroad, as regards to RAID vs AHCI - Intel actually recommend that you use RAID instead of AHCI even if you're not using RAID features as this gives you...

_"Maximum flexibility, due to the issues caused when the mode is switched once an operating system has already been installed."_

... it is possible, if our nub 'technicians' built a machine with IDE enabled (AHCI is a requirement for our builds) I'd have to come in and swap 'em over to AHCI with Windows installed, from my own experience the RAID mode that Intel recommend you use doesn't offer any more benefits than AHCI _unless_ you're going to bung in another drive and RAID them.


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## Deleted member 3 (Jan 13, 2010)

InnocentCriminal said:


> mikek75 was right with _Random_ array it is either.



No it is either inexpensive or independent, R always means redundant. Random makes no sense whatsoever.


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## Mussels (Jan 13, 2010)

DanTheBanjoman said:


> No it is either inexpensive or independent, R always means redundant. Random makes no sense whatsoever.



^ what he said. JBOD is the only raid that would make sense with random


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## mikek75 (Jan 13, 2010)

I already admitted I'd f***** up with the R abbreviation.


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## InnocentCriminal (Jan 13, 2010)

DanTheBanjoman said:


> No it is either inexpensive or independent, R always means redundant. Random makes no sense whatsoever.



I'll have to find the literature I have that states random - actually Mussels stated it before I finished my post. It's JBOD I was thinking of.


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