This is an old UEFI BIOS based on EDK1 (pre-ME8 era). You can add EFI SataDriver there, but there are very small chances it will work properly because it's for EDK2-based BIOSes.
There is enough free space in DXE volume and it's already LZMA-compressed, so any additional compression won't help at all.
My advice: just use OptionROM and be happy, no need to try anything.

I actually Read the option rom methode,

But it lead to more confusion then ever.

As the option rom is actually hidden.

I did found the tutorial(Link), but, I actually dont really understand how to implent it. It said updating the option rom over the adding in a module. It did had a section where you can add missing module.

I did, uhm, do i have to insert the Sata Vendor Id and device I?

Uhm...

Thanks for helping everybody.

For some reason it worked. The insert without the "for option rom only" checked.
Im eager, Very eager to test it out. I'll let you know. Oh and here is a pic.


Edit one:

Well..

I guess N73SV, hates UEFI, while having UEFI option.

When trying to install windows 8.1 form a GPT usb drive, it just simple locks up at the windows 8.1 Logo with 1 or 2 dots frozen on the screen.

Well back to good old MBR and OROM.

Oh and MBR UEFI bootable usb doenst work either.

Now I know more.

Edit two : After installing the GOP module, still no go. Oh well. Researching and testing is fun.

I never need to insert a RAID OROM or an EFI SataDriver to my BIOS if I only use AHCI, right? And is there any advantage of inserting an Intel GOP Driver to my BIOS if I use a discrete card anyway? I'm aiming for a pure EFI boot here.

EFI IRSTe SATA RAID - v4.2.0.1036
EFI IRSTe sSATA RAID - v4.2.0.1036
SCU Driver not found. :(

Unlucky, while the OROM Legacy works (I've added it with no problems at all), the EFI RaidDriver (I've the GUID 91B4D9C1) doesn't.

I've a Maximus VI Extreme motherboard. I think SoniX could fix this issue.

Anyway thanks for sharing the source files.

I used both UefiTool and MMTool replacing the SATADriver (which is compressed) with the one you linked (uncompressed) and after flashing
via USB Flashback, I can't disable CSM. If I do, EFI Rom doesn't appear in the bios menu, while the Legacy one (OROM) is the only one which
works.

I've the same EFI/SataDriver 91B4D9C1 like you, but it doesn't work on Maximus VI Extreme, while the 14.0 rom, using UBU, works like a charm.