I gnash my teeth every time I hear someone associating these two things. UEFI and graphical BIOS Setup have absolutely nothing to do with each other! Once upon a time, a (IMHO) less than ethical board vendor, as a marketing ploy, said they were the first to ship a UEFI BIOS (because they were the first to ship with graphical BIOS Setup) and that the two were closely tied to each other. This isn't the case. In fact, Intel (and others) had been shipping UEFI-based BIOS for a couple of years before this claim was ever made (they just hadn't delivered a graphics BIOS Setup program yet). Still, the naive believed their claims. Let's set the record straight. You can have graphical BIOS Setup in a legacy BIOS. I don't know of anyone who actually delivered this capability, however. It's certainly true that UEFI provides a better platform for developing graphical BIOS Setup programs. In fact, it may be that no one took the time to develop one on a legacy BIOS because it was a steeper hill to climb. Regardless, what is certainly true is that the (marketing) value proposition for graphical BIOS Setup was identified at roughly the same time that UEFI was being rolled out. No, I didn't just contradict myself. What Intel first rolled out was technically called an EFI BIOS. EFI was the name that Intel gave to the technology. It was renamed to UEFI only after Intel made the framework freely available to the industry and it was ratified as an industry standard.
I won't go into the design and architecture of UEFI; there are plenty of web sites and books (get the books; some good friends of mine are amongst the authors) that will provide you with this information. I will simply answer your questions in as non-technical a way as I can (and let you investigate further if you are interested)...
- No, enabling UEFI will not get you a graphical BIOS Setup program (or, as the case may be, a better graphical BIOS Setup program). Fact is, when these boards were released, Intel had not developed their (own) graphical BIOS Setup program. In (or slightly after) this particular time frame, Intel delivered a few boards with a BIOS that had (what I call) a "pseudo-graphical" BIOS Setup program, but this was based upon a third-party BIOS developer's graphical engine, not Intel's.
- (IMHO) No, there is no performance advantage to using the UEFI boot engine over that of the legacy boot engine. You use UEFI if you need/have to - such as is the case if you have drives large enough that they cannot be supported by the legacy boot engine. There are some other considerations as well. For example, some of the newer graphics cards have OpROMs (Option ROMs - flash chips that provide code that the BIOS can use to support accessing the device) that only provide support for the UEFI environment (they dropped support for the legacy environment since (my guess) supporting both takes more work); only by enabling UEFI will these cards work with the BIOS. [Aside: many of these newer graphics cards won't work with these boards anyway; the cards require PCIe 3.0 and these boards only support PCIe 2.0.]
- UEFI utilizes a different architecture for maintaining information about the partitions on a drive. A drive that is formatted for legacy boot (i.e. with legacy partition table) cannot be used with UEFI. Thus, if you want to use UEFI with Linux and you have only a single drive, you cannot keep the legacy installation of Windows 7 (you would have to reinstall with UEFI enabled - or use a second drive). Remember too that you need to prepare your installation media for booting with UEFI if you want to use it to install a UEFI-based O/S installation. If you use legacy boot to boot from this media, you cannot install for UEFI boot. I mention this because many of the images for installing Windows 7 can only be used with legacy boot; they contain the UEFI folders and files that are required, but these are ignored if the device is legacy partitioned. This is the issue that has caused problems for some NUC users attempting to do a UEFI install of Windows 7 (there are *lots* of conversations regarding this).
I hope my verbal diarrhea doesn't make this too hard to follow...
Many thanks for the fast reply. It was not verbal diarrhea. Actually you covered an issue I had forgotten which was your point number 2 about the Video card and UEFI. My specific card does not support UEFI boot unless I do a video card BIOS flash. It is not hard, but I would prefer to keep it as legacy so my existing parts keep working as they do now.
Based upon what you provided, my first inclinations to not mess with it was correct, but I had to ask. Thanks. .