Just found that Gigabyte has posted many released version for supporting 3TB.
e.g. http://www.gigabyte.com/products/product-page.aspx?pid=3646#bios
As I know that there is a BIOS option to select whether using the EFI or not.
Guess that a partial of EFI is implemented but not a whole EFI...
The latest BIOS release will support 3TB HDD booting. You will need to use the latest @BIOS from Gigabyte website for updating the original BIOS to EFI-enabled BIOS.
First... use Win7 as you are a newbie to RAID...
Connect all your HDDs on SATA2_2, _3 (ICH10R)... Enable XHD in BIOS which you already did...
RAID0 striping size could set to 16KB for better performance...
If you have to go with XP... visit Gigabyte website for F6 pre-install driver. Load it...
Which SATA port are you using? Is it from Intel ICH or Gigabyte SATA?
What is the controller type you set in the BIOS?
AHCI = should be no problem to plug your eSATA drive when OS has loaded.
IDE = try attaching your eSATA drive to the system before you switching on the power.
The root cause is found to be Ubuntu problem. Ubuntu built-in driver for Realtek has used the incorrect 8169.ko. 8169.ko will cause two registers inside LAN GPHY to have incorrect values, thus, causing the LAN GPHY stops working after system shuts down from Ubuntu. To solve this, you must clean...
Patriot modules? Enter the BIOS, ramp up the DDR voltage first, save and exit.
Enter the BIOS again and now configure the DDR frequency, save and exit.
Enter the BIOS once again, now configure the timings, save and exit.
Try it.