Hi Guys,
I looked at several articles where a very similar motherboard was discussed - GA-Z68X-UD3H-B3 and in many ways I found answers to my questions, but I thought it necessary to make a new topic and clarify some points. I would like to divide my request into two parts. first of all, we are talking about the modification and nvme support of GA-Z68x-UD3-B3, and the second part is about the rationality of choice, the perceived risks and, of course, the expected benefits. I want to highlight that this is about my personal choice, but it would be nice for me to hear some recommendations and tips. especially from Lost_N_BIOS, noticed very good recommendations from him 
, always very detailed and clear answers, especially regarding these board versions.
So let’s probably start with the second part first. I have the following:
CPU: i5-2500k
GPU: gtx 1070 / gtx 1060
MB: GA-Z68x-UD3-B3 (F7 bios) Win7
I am planning to buy Samsung 860 (sata) or 970 evo plus (M2 + adapter) and make it bootable using win10. I had f11 for some time, but I returned to f7 due to some problems, I also have disabled the power saving on the CPU, strange but at some point if this is turned on the system simply does not work. And as far as I understand U1F (UEFI BIOS) does not provide nvme support, therefore it is necessary to modify. But first I would like to ask if it’s all worth it? I got some advice elsewhere and quite a lot of advice in favor of SATA as the easiest way. the main arguments were that the difference would be almost imperceptible, only when copying large files but not on loading’s. that the major bottleneck in most day to day usages isn’t the theoretical maximum bandwidth a drive can do, but the random performance, which is limited by the controller and if it has a DRAM cache or not. that Win 10 with full updates are working unstable and in general, M2 connectors are more needed for cinematography, otherwise there is practically no difference with SATA speed’s. considering that I have PCI Express slots 2.0 one slot is connected by graphic card that will work from PCIEX16 to PCIEX8 (is it worth worrying about this?) and the second with M2 adapter from which I only get ~ 1.5 GB/s but it’s still much better than ~ 500 MB/s from sata and only the desire to make it bootable adds additional bother. So is it worth it? are there any real risks of getting a buggy system?
As for the first part of the request, here I wanted to ask for help in creating necessary files for modifying my board. all the modification steps do not look like something complicated for me and I see many people have no problems in their work after that. however, some are faced with “DXE Driver Volume” is nearly no space for the insertion of an additional NVMe module and in this case, we need to remove other modules. so actually , I would be very grateful for a small guideline or advice from anyone who has experience with this on this motherboard.
Thanks in advance to everyone who will answer and give their recommendations!
NVMe support for Gigabyte GA-Z68X-UD3-B3 (SATA or M2 / possible risks and finding the best solution)
@Rav106 - That’s a tough one there, with your 2500K SB CPU I suggest staying on the old non-UEFI BIOS, and even if you had 2600K IVY CPU, which works better on the newer beta UEFI BIOS, I’d still suggest you stick with the old non-IVY BIOS for IVY CPU too, simply due to the general bugs in those BIOS.
Yes, only the UEFI BIOS can be modified to boot from NVME, otherwise below is several methods to boot NVME on legacy Non-UEFI BIOS
[Guide] NVMe-boot without modding your UEFI/BIOS (Clover-EFI bootloader method)
[Guide] NVMe-boot for systems with legacy BIOS and UEFI board (DUET-REFIND)
X58/LEGACY BOOTING FROM NVME DRIVES (PIZUSKI METHOD) (MOST QUICK&SIMPLE WAY)
Yes, in reality, NVME outside of large file transfers and or benchmarks, you really wouldn’t notice any difference vs SSD, maybe a second faster startup but that would not be worth all the BIOS bugs/issues of the UEFI BIOS
I’ve never used the non-UEFI legacy options, so i don’t know how that is in regards to booting faster/similar to UEFI mod BIOS, or if it’s process in general adds a few more seconds or longer to the boot time overall too.
But general day to day usage, gaming, browsing, downloading some files etc, you really would not notice much difference if any at all in a SSD vs NVME situation. Only when you move huge things, or many files at once, or benchmark the drive, then you’d see large differences.
If you have IVY CPU, you would “maybe” also get PCIE 3.0 speeds out of one of the PCIE Slots, but I’m not 100% sure about that on this model
If you game, you would not want NVME in slot that cuts your graphics down to x8, if you do not game then this would not matter at all.
Onboard M2 adapter = useless, do not use this for anything
If you want to test the UEFI BIOS I can mod U1F for you, let me know.
For this, if you want, go ahead and get flashed over to U1F stock first and use it for a bit, see if you are OK with it, or hate it etc, then you can decide if you want to use this and NVME boot, or stick with older BIOS and legacy NVME boot, or use SSD
It may be time to upgrade board and CPU Some nice priced 4C/8T CPU’s ($120 range) for LGA1200 boards now, and both boards and CPU are cheap, if you look at the budget end of things.
Thank you very much for your detailed reply 
So the main thing is that UEFI with my CPU and board is very buggy and there a lot of gaps to use it stably?
Actually I was thinking about the full system upgrade and that’s why I’m considering buying "970 evo plus", then just put it into the new board with M2 connector… but for now use PCIe adapter for my current board. Bad thing for me that I really want to make a new SSD bootable, not from USB flash drive, but from BIOS. And it seems, now I am probably convinced that it is better not to do this and stay on 860 evo SATA with my current F7 bios. besides i need a graphics card in my work (here, of course, I have some doubts that there is some kind of difference between x16 or x8 
)
Thanks for your suggestions to modify U1F for me. as far as I understand, win10 updates can also affect the instability of work? in this case it will always be a test system for me, which I would not want. Honestly I would rather keep my system stable and not be distracted by it all the time.
Here I meant something like this - https://www.amazon.com/QNINE-Adapter-Exp…n/dp/B075MDH28Y
@Rav106 - Sorry for the delayed reply, I lost your thread and just not found while searching!
Yes, you can use adapter like you linked
Win10 should be OK