SATA(AHCI) controller performances

[Mereth]

Hi,

I'm currently looking for the best controller to run in my guests. I read in the manual "Like a real SATA controller, VirtualBox’s virtual SATA controller operates faster
and also consumes less CPU resources than the virtual IDE controller.", but it seems to be wrong, at least with windows host & guests.

Host Configuration:
E8500@4Ghz
Raid0 2*Raptor 74Go
WinXP SP3 without antivirus during the tests

Guest: Win2003 SP2 R2

My Test Plan was to use the command line tool "sdelete -c", on a 10Go fixed size VDI containing an empty 10Go NTFS partition, with PIIX4, ICH6 and SATA(AHCI) (with Intel Matrix Storage for SATA(AHCI) support driver) controllers. And i looked for the time it takes to run the tool (with the Host clock) and the Host cpu usage.

• PIIX4 : 4mn with 5 to 10% cpu usage
• ICH6 : 4mn with 5 to 10% cpu usage
• SATA(AHCI) : 7.30mn with 10 to 20% cpu usage

Did i something wrong with this tests or is it a Windows issue ? Because, at this time, i don't see any advantage to use something else than the default PIIX4 IDE controller.

[vbox4me2]

Use IDE only and toggle SATA box on, make sure sata/ahci drivers are installed for the Guest.

[Mereth]

I'm sorry, i don't understand your message, for me it's useless to activate SATA controller for someone who want to use the IDE controller only.

[vbox4me2]

You're asking for sata performance and you only want to use ide??? make up your mind.

[Mereth]

Sorry, i did'nt say that, u did, isn't it ?

Use IDE only and toggle SATA box on, make sure sata/ahci drivers are installed for the Guest.

My point is the manual say the SATA controller is faster and consume less cpu than the IDE controller, but my tests demonstrate it seems to be wrong. I would to know if the problem is in my tests, the Windows guest, the Windows host or the VBox manual. Is someone experiencing better performances when using the SATA controller ?

[vbox4me2]

Yes ofcourse or I wouldn't have said that, using sata drivers on a Guest and enabling it for the Guest will increase IO speed by 10x(windows), for the Host it makes no difference to the Guests what is being used since its more or less emulated.