Hi there,
I'm struggling with an issue with my lab. The mobo is an ASUS P9X79 with an intel i7 3930K.
I recently purchased an LSI Megaraid 9240-4i to add some SSDs and tried to boot on an ESXi 5.5 version using an install USB key.
Using the 'standard' ESXi 5.5, the install usb key hangs at loading lsi_mr3.v00 as described here :
https://communities.vmware.com/message/2303271
The workaround (deleting lsi_mr3.v00 and copy/paste+rename lsi_msgp.v00 into lsi_mr3.v00) is working.
But then, the installer hangs at 'loading module megaraid_sas", as here :
How can I make LSI MegaRAID SAS 9240-4i working under ESXi 5.0?
The workaround seems to set the BIOS to UEFI only, however if i do this, the USB key no more seems to boot (cannot test if it will go though the whole boot process) so my problem seems to be the USB key which cannot boot into UEFI mode. If anybody could provide me an advice about booting an ESXi USB key into UEFI mode that would be great 
Any help/advice appreciated.
Regards,
PS : latest BIOS version on the mobo and latest LSI firmware applied on the card of course.
Apparently it comes from the card itself 
according to this post :