Tutorial : How to switch from IRRT to AHCI mode - E6400/E6500 (Vista)

Is there any documentation on this performance hit? Also, doesn't ATA mode turn off the eSATA port? I also wanted to use an external eSATA HDD.

Harvey

 

AHCI's Native Command Queuing is mostly not supported on SSDs.
AHCI can cause stuttering with some SSDs using JMF602 Controller (i.e. OCZ Core-Series oder Transcend MLC or Supertalent Masterdrive Series).

On other SSDs with better Controllers (like Mtron Mobi Series) you can see increased performance on about 10% Read/Write with AHCI.

 

Any idea how the Samsung 1.8 inch SSD's play with AHCI?

 

I was successful in switching to the AHCI mode...but my audio continues to stutter. Do you think there is a way to switch to ATA mode without the BSOD? Thanks!

 

I had a Samsung SLC 64GB (Read/Write 100/80). This was really good in AHCI but I never tested it on ATA only heard of others (OCZ Core etc.) having problems on AHCI.

 

There were some NCQ performance issues with Vista's native AHCI drivers & some SSD drives last year, but not when using Intel's Matrix Drivers (IMSM), which work just fine.

In addition to IMSM AHCI's faster overall performance due to NCQ and other improvements, Smart monitoring etc, you also benefit from significant LPM/DIPM power savings over legacy IDE which according to tests I've read give a 20% advantage to AHCI.

So I don't see any benefit to using legacy IDE.

Edit:
Found documentation at Intel that also confirms Vista's AHCI driver bug with SSDs. In fact Intel recommends using AHCI with their SSD's.

Scroll to the middle of the page to Do Intel SSDs need special driver support?


Do Intel SSDs need special driver support?No, the standard drivers for any HDD will support Intel SSDs as drop-in components, such as those bundled with Windows*. However, for best performance, a driver that supports SATA Native Command Queuing (NCQ) is recommended, such as the Intel® Matrix Storage Manager (IMSM) driver from Intel.

Note: The Windows Vista* driver has a bug which does not allow NCQ on Intel SSDs. For Vista*, only IMSM is recommended. An update will be provided when this issue has been resolved.


Is the Intel SSD a drop-in replacement for SATA Hard Disk drives?
Yes, providing rugged, reliable performance at lower power. Intel SSDs support the ATA-7 command sets and the SATA II command extensions. AHCI must be supported and enabled by both the system BIOS and OS (May require F6 installation of compatible windows storage driver like IMSM. Note: Vista AHCI support is native)

 

@MiB - WORKED PERFECTLY!!! Thank you!

 

Great ! So it works for the M series as well.
Thanks for confirming.

 

My DCP Latency spikes are now COMPLETELY GONE!!!!

 

Exactly