Were you able to get the SSD working on your XPS720?  I have been considering adding a SSD to mine.

Cool, thanks for the reply.  Here is a little info I found on the Intel website regtarding the P55 Express Chipset.  I don't think AHCI is supported on the XPS720 as it would have an older chipset.

AHCI

Hi

Thanks for the info on ACHI I think your right as if it was an option it would be something you could select form the biosand it isnt.

Hi

Yes it works fine my disk data transfer rate scores 6.8 on the windows experiance index. I am currently running windows 7 64 bit I used a raptor 120GB 10000 rpm before and that scored 5.9 so Im happy.  

AHCI is part of the "raid" selection, SATA\IDE is the "on" selection.  It is common on many Dell computers, just not very intuative.

The XPS 720 only supports AHCI as it is a SATA system.

Thank you Bacillus,

I should have typed out the full directions like you did.

If you just change the bios option to raid to get ahci then you'll blue screen.

You'll need to do this first:

1.Exit all Windows-based programs.
2.Click Start, type regedit in the Start Search box, and then press ENTER.
3.If you receive the User Account Control dialog box, click Continue.
4.Locate and then click the following registry subkey:
HKEY_LOCAL_MACHINESystemCurrentControlSetServicesMsahci
5.In the right pane, right-click Start in the Name column, and then click Modify.
6.In the Value data box, type 0, and then click OK.
7.On the File menu, click Exit to close Registry Editor.

After this you’ll have to restart your computer, go to BIOS and enable AHCI. When you log in to Windows again, you’ll notice the installation of drivers for AHCI. Another restart will be required to finish the driver installation.

These steps are provided at your own risk and not suggested unless you know and understand the risks. You will want to make sure the controller driver and MB BIOS support this option before you enable it