11 Replies Latest reply on May 2, 2018 11:48 AM by JNRW

    NUC 5i5RYH Boot Setup


      I have pressed F10 and have looked at the Boot setup and would like some advice, please.


      a) Boot Priority.  I have Legacy Boot enabled and not UEFI. Is this OK? I do not know if it makes a difference but I have BIOS version 0367 installed as 0369 slows it down unacceptably. I remember when switching back from 0369 to 0367 it mentioned something about legacy. I wish I had paid better attention.


      b) Boot Configuration.  I have Boot from USB First enabled and not Fast Boot. I remember changing it when I did a clean install of W10. Should I go back to Fast Boot? Does it matter?


      c) Secure Boot. This is not enabled. I do understand that for this to be enabled then UEFI Boot in a) above must be enabled first. Should I enable Secure Boot?

        • 1. Re: NUC 5i5RYH Boot Setup
          Intel Corporation
          This message was posted on behalf of Intel Corporation

          Hello JNRW,

          To answer your questions in order, please take a look to this information:

          A ) We always recommend to use UEFI boot as it provides more security features than the legacy boot which is also known as “BIOS” mode, UEFI works together with the secure boot feature. The way the system firmware works along with the operating system on UEFI provides more flexibility to the user, and advantages such as:

          Bootable devices can be greater than 2TB in size (GPT)

          If the operating system gets corrupted by a virus or malware, the system will prevent the system from booting, providing more security to your system and data as the system can be restored on the future.

          UEFI is also recommended with the newest OS, so if you are running Windows*10 it will be the best option for you.

          Regarding your BIOS, the latest version should be optimized for your device, meaning that it should work faster, or with the same speed as before.

          You can try a BIOS recovery in case something went wrong during the update, you can perform it by following these instructions:


          Here you will find the latest BIOS for your machine:


          B) Booting from USB first should be enabled if you want to boot from an USB device.

          Fast Boot is a feature in BIOS that can help to reduce the time it takes to boot your computer, since it won’t wait for an USB device to be found and recognized in order to boot.

          You can find more information about it here:


          c) As shared before, this option works hand on hand with UEFI so you can enable both, as it prevents the system to boot if there is any malware, virus or data corruption on the OS.

          I hope this helps.

          Best Regards,

          Diego S.

          • 2. Re: NUC 5i5RYH Boot Setup

            Hello Diego S.


            First of all I want to thank you very much for a most comprehensive answer to my queries.


            I now intend to change the Legacy Boot to UEFI Boot, enable Fast Boot and enable Secure Boot. Could you confirm I can do these three operations all in one session?


            If I upgrade the BIOS from 0367 to 0369 should I do this before or after the above?


            I say ”if” because I am very unsure about this. When I upgraded from 0367 to 0368 the performance drop off was significant and I rolled back to 0367 with no problem. As we all know 0368 has since been withdrawn. However, when I upgraded to 0369 I experienced a similar significant slowing down and again rolled back to 0367. My question is, if I try again to install 0369 (and I will try it) and I do not like the effect can I roll back to 0367 again?


            Thank you again for your attention to this matter.

            • 3. Re: NUC 5i5RYH Boot Setup

              According to the release notes, the only change is the inclusion of the updated microcode. There were no security updates or ME firmware updates that would preclude it, so you should have no issues returning to BIOS 367 if you want to (though I don't recommend it; sample code showing how to attack these vulnerabilities is starting to appear (even in GitHub) ).


              The NUCs with 4th (Haswell) and 5th (Broadwell) generation processors had the most "issues" with the original microcode updates. Suffice it to say, the unstable operation that resulted was really problematic. The corrected microcode has been exhaustively tested (that's why it took so long) to be stable and, since the changes are only for the SpectreB vulnerability, you should not notice any major slowdowns as a result.


              Hope this helps,


              • 4. Re: NUC 5i5RYH Boot Setup

                Thank you indeed for your answer.


                I will try 0369 again and maybe stay with it a while to give it a good work out, so to speak. At the risk of your stealing Diego S.’s thunder could you give me your take on my other queries regarding the various Boot options and the timing of the BIOS upgrade?


                If you feel it should be he who answers, then fair enough.


                Thanks again.

                • 5. Re: NUC 5i5RYH Boot Setup

                  Well, I answered because you'd have to wait for Monday to get a response from Diego. I don't give a d@mn about thunder; he is welcome to it.


                  If you are using a legacy O/S (Windows 7, Linux, etc.), then you can certainly stay with only Legacy boot enabled. I would note that you can have UEFI enabled and still boot Legacy O/S images, so I usually leave UEFI enabled. A minor inconvenience in this case is that, if you have two bootable images on your disks/partitions, one using UEFI and one using Legacy, it will always boot to the UEFI-enabled image. You will need to (manually) use the F10 key to specify to boot to this legacy-enabled image. If your images are all Legacy, then no issue; leaving UEFI enabled in this case would allow you to boot from a UEFI-enabled image off of a USB flash disk.


                  I recommend that you do not enable Fast Boot. It creates all sorts of issues for getting back into BIOS Setup, etc. At the same time, it will really not save you any boot time. The BIOS is so well optimized that the savings is very tiny. Just not worth it.


                  If you would like the additional security provided by the Secure Boot feature, you definitely need to enable UEFI. If you are using Windows 10, then great -- so long as you installed it in UEFI mode; if you didn't, then you likely have to install it again. If you are using Windows 7, understand that it does not support the Secure Boot feature and you cannot use it.


                  As for timing, there is nothing between the two BIOS releases that would create a dependency. You can upgrade the BIOS before doing this or after. My recommendation is to upgrade the BIOS first.


                  Hope this helps,


                  • 6. Re: NUC 5i5RYH Boot Setup

                    Yes I was hoping for your answer specifically because of the weekend , however, I wish no disrespect to Diego S.!


                    I clean installed W10 last year but do not remember whether it was under UEFI or Legacy. As Legacy is enabled now I presume it was under Legacy but I wonder whether when I reverted back from 0369 to 0367 it could have moved from UEFI to Legacy. As I said in my first post I remember something about that but nothing specific.


                    I take your point about Fast Boot and will ignore it but I will upgrade the BIOS to 0369 first and then enable UEFI (if the system allows) and Secure Boot. I definitely will not be doing another clean install of W10 though. I will, however. give 0369 a more extended trial.


                    Thank you indeed for your response, it is much appreciated.

                    • 7. Re: NUC 5i5RYH Boot Setup

                      Can someone please help me.


                      I upgraded to BIOS 0369 a couple of days ago and all is well.


                      I have just gone into BIOS and enabled UEFI and Secure Boot and now when I switch on the NUC there is nothing. Yge TV monitor just says No Signal. I did nothing other than change the two settings and pressed F10 to save and exit.


                      I have checked all cables and connections.


                      What has happened? What can I do?

                      • 8. Re: NUC 5i5RYH Boot Setup

                        It’s currently OK now having booted on my command from a list of Boot options.


                        I will go into the BIOS set up another day and check it out as far as my limited knowledge will allow.

                        • 9. Re: NUC 5i5RYH Boot Setup

                          Following on from my panic a couple of posts up I have now been able to reinstate my previous setup, which is Legacy, no Fast Boot and no Secure Boot and it all works well now again.


                          I ought to follow the mantra if it ain’t broke, don’t fix it but I am inquisitive.


                          N. Scott Pearson said that if my clean install of W10 was carried out under Legacy Boot terms then it needs to be done again under UEFI terms in order to allow the UEFI (and Secure) Boot options to work. Have I understood that correctly?


                          If the answer is yes, would it have to be a clean reinstall using the Media Creation Tool or could it be the similar method which allows all the data, files, folders, software to remain intact and untouched? If it is the former I think I shall leave it; if the latter then it might be worth a go.


                          Looking forward to a response, for which I say thank you in advance.

                          • 10. Re: NUC 5i5RYH Boot Setup

                            Scott is correct. You will have to reformat and reinstall Windows if you want to use UEFI and Secure Boot. The GPT format is used when you do an UEFI install which adds a couple of extra hidden partitions to the install.

                            • 11. Re: NUC 5i5RYH Boot Setup

                              Thank you MrMitch for your reply.


                              I am going to leave it it alone now as it works OK, but I have learnt a lot from my first foray into this forum.


                              Thank you all who have helped. I shall mark this question as answered.