I'm trying to free up as much orom space as possible on this motherboard. Would it be possible to completely remove some of the devices from the bios? Specifically the Thunderbolt card, Any of the Intel PXE Boot stuff, The onboard video. Im not sure what else occupies the space or what can even be removed?

My issue is the i'm using a LSI Megaraid controller on this PC and when theres not enough orom memory it wont load all the drives connected to the card and even disabling some of the bios options still doesnt free up enough space. I can take the exact same card and drives and install it on my P8Z77-M Pro and it all loads up fine. The -V Premium has too much extra crap hogging up the space. Ive actually had the Raid card working on the v premium once before but now no matter what bios options i choose it wont give the LSI card enough space to work 100%. It boots but only 1/6 drives are recognized. Before when it wasnt recognizing all the drives i just disabled the thunderbolt card and it worked fine. now no matter if i disconnect everything but a keyboard and disable almost everything in bios all the legacy boot stuff and everything else except what is needed to access the lsi card. it still wont load all the drives. This all started after my PSU went out and i installed new one. I flashed a few different bios's hoping that maybe it would clear the memory. Ive also reset cmos and pulled the battery. ive tried many differnt things 100 times to get this working again and it just wont work. no reason why. and as i previously stated i can pull the card and all the drives and stick in another pc and all is well so it has to be something with the orom memory but as far as moding the bios to remove things all that is over my head

Link to the newest bios for this mobo

https://dlcdnets.asus.com/pub/ASUS/mb/LG...M-ASUS-2104.zip

i figure there has to be a way to completely remove a few things to clear up the orom space. theres tons of reports of issues with raid cards because of lack of space. any help or advice would be greatly appreciated. hopefully what i wrote even makes sense lol thanks

First two you mention, yes, but removing onboard video (vBIOS/GOP), I'm not sure if that would cause issues or not.

Usually the problem with what you mention is not about other roms using up available memory, but the card wanting to open up memory space in a size larger than the BIOS is coded for. But, sometimes what you mention will help.
Since it does work for you on P8Z77-M Pro, then you may have luck on the P8Z77-V. Both of those have onboard GPU stuff all the same, and probably same PXE stuff too, so Thuunderbolt and any additional SATA controller roms that the other doesn't have may be the only issue.

If it worked before, with BIOS as is, but not now, have you tested this card on other machine (recently) to be sure it's still working properly? If yes, reloading optimal defaults may help. Or, use same BIOS as you did before, if you are using some other one now.
BIOS reflash could help too, if you do that, be sure to load optimal before you start making settings changes.

To me, I don't think it's the BIOS needs modified, since you say it worked before, but not now. Sounds like you need to find the correct settings you used before that worked, ie disabled stuff I assume.

If you are not using RAID you can also remove all the RAID Roms (legacy and EFI)

Thank you very much for your response! I figured out what the issue was! It was the power supply... My Corsair Pro Series power supply doesnt like the WD white label hard drives that were shucked from the easy stores. I taped off the 3.3v pin on all of the drives and BOOM! The weird thing was that all the drives are the same but one drive was powering up and loading and none of the others were.. so i was assuming they were all getting power. I had finally jumped power from the working computer power supply over to those drives in the non working computer and they all finally loaded. omg i had been pulling my hair out for 3 days over this... of course my $50 thermaltake power supplies didnt have any issue powering the drives but my $300 corsair doesnt like them lol... either way thank you again for taking the time to respond to me and give me some advice!

You're welcome..... Wow, really?? That's a new one
Glad you were able to find the solution and cause of the issue here, and thanks for posting about it for the next guy that may run into issue too.