AHCI SATA mode versus ATA mode...

Is your drive performing at its maximum capacity?

If you are running in ATA mode, probably not. But then again, it depends on if you have a SATA drive or not... A 3GBPS SATA drive will perform better in AHCI mode than it will in regular ATA mode.

What the hell are all these acronyms anyway? Well, in an effort to not bore anyone or actually put them to sleep, here is a brief explanation. (you can get this too, from Google or Wikipedia...)

ATA= Advanced Technology Attachment (also known as Parallel ATA or PATA)
SATA= Serial Advanced Technology Attachment
AHCI= Advanced Host Controller Interface
GBPS= Giga Bytes Per Second (not giga BITS per second, which is different...)
DMA= Direct Memory Access
SCSI= Small Computer System Interface
SSD= Solid State Drive

Suffice it to say that AHCI is a better implementation, or a more ADVANCED version of ATA. It allows for things such as hot-swapping and native command queuing that make drive access and sustained throughput rates faster and larger, respectively. It is a standard that is NOT supported by XP, partially implemented in Vista and has native support in Windows 7.

Will your computer support this new mode? Chances are, if it shipped with Vista installed, then yes. Only way to tell is to check the BIOS, in my case the laptop shipped with Vista downgraded to XP and because of the lack of support for this mode in XP the default from Dell was OFF.

So what do I do? I see it is off, so I enable it in the BIOS. Then try to boot... Instant BSOD (Blue Screen Of Death). Seems as though if you don't enable it upon initial installation, then the OS isn't prepared for it properly. (driver needs to load first...) You can first change the registry entry that loads the driver, then enable it in the BIOS upon next restart though. Let me warn you again - Editing the registry can be dangerous to your computer and your sanity. I cannot be held liable for anything you do while editing the registry of your computer. If you have never edited the registry, or if you feel uncomfortable even thinking about editing the registry, give your laptop to some geek who has done it before, and let them do it for you.

Couple AHCI mode with a fast hard drive and you get wicked, almost evil performance from your hard drive. Unless you are running a fiber-channel SCSI drive subsystem you can attain the fastest drive access using AHCI mode and hi-RPM drives. (talking 7200 RPM and greater) The only other thing that can begin to compete is SSD, which has no moving parts and can achieve faster access times. Throughput is a problem with SSD, and here is where large, fast AHCI SATA drives can outperform anything else.

In all reality we are talking about nanoseconds here, chances are as humans we wouldn't see any difference. I can hear many of you saying 'Who gives a shit anyway, I just want Windows to BOOT..." And I understand that. It is just that I want more out of my stuff than the regular guy on the street. I want it to do all it is supposed to do. If it has a 'regular' and 'fast' mode I am gonna choose FAST. And I think YOU should do that too. If it doesn't work, MAKE it work. If you don't know how to make it work, then LEARN how to do it.

If I can do it, you can too.