Disk modes in HD tune

Admiral Huddy · 25 Feb 2009 at 15:32

I've just noticed that my Samsung spinpoit shows the following in HD tune:

Supported : UDMA Mode 7 (Ultra ATA/512)

Active : UMDA Mode 5 (Ultra ATA/100)

Is this right?

I take it that my drive is not running at the faster bandwidth... what do i do to change this?

Greenlizard0 · 25 Feb 2009 at 15:52

Urrrh, bios setting? I have no idea sorry.

DigitalReaper · 25 Feb 2009 at 16:52

Under XP it should be configurable in the IDE channel properties (not the drives/controller) in the device manager IIRC.

edit: maybe not, it's only letting me choose between PIO and DMA here.

Talrinys · 25 Feb 2009 at 17:11

I get the same on my Seagate drive and it kinda puzzles me, but i never really looked into it because i don't need the bandwidth on my drive anyway, but does anyone have any idea why it's doing this?

ChrisLX200 · 25 Feb 2009 at 18:28

You got SATA interface set to IDE mode in BIOS maybe? Ususally a choice - IDE (default), RAID, and AHCI. The latter offers enhanced performance like NCQ.

lopkinfop · 26 Feb 2009 at 15:49

but installing windows using the ahci doesn't work unless you intall the drivers prior to the setup (when it says press f5 to install XX), there is a way to enable it after instaling windows, a google should find it

Admiral Huddy · 27 Feb 2009 at 08:44

ChrisLX200 said:
You got SATA interface set to IDE mode in BIOS maybe? Ususally a choice - IDE (default), RAID, and AHCI. The latter offers enhanced performance like NCQ.

I'll investigate this.

lopkinfop said:
but installing windows using the ahci doesn't work unless you intall the drivers prior to the setup (when it says press f5 to install XX), there is a way to enable it after instaling windows, a google should find it

Can you changing this to AHCI after windows is installed?

CaptainCrash · 27 Feb 2009 at 09:12

Admiral Huddy said:
Can you changing this to AHCI after windows is installed?

Nope, you'll get a BSOD as soon as it boots.

Well, there *is*a way of doing it, but it's fiddly, and for desktop use it's unlikely that you'd see much if any performance benefit - NCQ really comes into its own with high queue depths of the kind you typically see in servers, and the theoretically higher SATA speeds will be bottlenecked anyway by the mechanical limitations of the drive. That just leaves hot-swappability as the remaining reason for enabling AHCI, and if you've no use for that you might as well leave the drives in IDE emulation mode and save yourself a lot of faffing around.

ChrisLX200 · 27 Feb 2009 at 11:04

Well you can, it's what I had to do as I installed my OS with it in IDE mode. You have to manually make a single change in the registry. As above, I changed to AHCI so I could hot-plug an eSATA drive and also take advantage of NCQ.