Ubuntu 20.04 boot problem on SM X10DAX with 2xE5 26xx cpus

[Doppelbauer]

I am new to Linux. Trying Linux/Ubuntu 20.04 on my SM X10DAX mobo, cpus 2x E5 2683 v3 (2x14 cores). Machine is working without any issues under Win10. Linux boot wont work, freezing on Supermicro boot screen.

If I introduce drastic Linux options in grub, mainly nolapic or (better) acpi=off, boot is working. With acpi=off, both cpus and 2x14 threads are available as expected, but needless to say, this option kills hyperthreading and some sources suggest possible problems with mobo fan and temp management. From a first glance at temps, these seem to remain ok, temps ramp up under heavy load, but very reasonably, fans seem to spin as normal. After stopping load temps come back quickly.

Any suggestions for other, less restrictive measures to make this work, and enabling hyperthreading? Thank you very much.

 

[RTM]

If you installed Ubuntu to boot via BIOS mode try UEFI (though it will require a reinstall) or the other way around if you installed to boot via UEFI.

Other than that you may want to ensure you have updated BIOS.

 

[Doppelbauer]

Thank you. Bios was updated to the latest version some time before. The culprit has been identified.

As I have written elsewhere in the forum I have successful applied the "all core turbo" unlock bios modification to my system months ago. This works for any E5 26xx v3 (only v3) as long they are not ES, with a stepping of a least 2, as far as I understand. This has been a full success, extremely easy to perform on a X10 board and gives you 20% performance multicore for free. With some additional mild base clock overclock (level 2) my sm X10DAX / dual E5 2683v3-system now achieves up to 9000 points in Cinebench R20 and 4000 points in Cinebench R15 (which is closer correlated to chess benchmarks, using e.g. Stockfish asmfish engines in Win10. As you might know, I use this workstation mainly for high load extended chess analysis, and 24/7 with 100% load is no problem for the system even after this modification. It remains stable as a rock. Temps and energy consumption are both only moderately higher.

Now finally back to my Ubuntu boot problem . The all core turbo modification includes a mandatory setting of few custom parameters related to C- and P- states in the advanced power configuration menu of the bios. The system will not work in Win10 without these settings. However, exactly these settings seem to disturb Linux/Ubuntu. Switching them off allows Ubuntu to boot without any issues. This is a little bit inconvenient in case of switch boot form Win to Ubuntu, but this is a minor hassle.

One little question: does anybody know if switching acpi=off in Grub could in fact cause problems with fan and temperature management on these Supermicro X10 motherboards? This could be a somewhat more convenient setting, as I do not really hyperthreading on Ubuntu.