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X99-E-10G-WS motherboard not boost all cores anymore with MCE

Level 7
On the latest and last BIOS. I haven't changed anything in the BIOS. Turbo = ON MCE = On Sync-All-Cores = 42. All cores used to boost to 42 when fully loaded. Verified with i7z.

i7-6850K processor

Now only four cores are listed working at 42 and the rest at 40. In reality under real load, only one core boosts to 40 and the rest stay at 38.

Again, nothing was changed in the BIOS. So something changed in the OS. Ubuntu 16.04 kernel 4.15.0-20-generic. I have checked and the cpu_scaling governor is set to performance. The max freq is set to 4200 and the min freq is set to 4000. I have been reading all day long trying to determine what and when things changed in the OS that lost my all core MCE boost to 4200. Haven't found anything. Any suggestions on what has changed and how to revert back to all core boost?

This is the output from i7z while loading all cores with Prime95.


Level 7
Not sure why I never followed up this post. I solved the problem and posted the solution over on the OCN forum for this motherboard. I will just copy my post from there.
An update to my all core boost woes. I saw that there was a new 0903 BIOS for the motherboard with manufacturer implemented Meltdown/Spectre fixes. So I flashed the new BIOS.

That forced a completely new and virgin BIOS configuration so I lost all my previous user profiles. The BIOS set up the memory and core clocks differently than what I had used before. It achieved the XMP 3000 memory setting by changing to a 125Mhz BCLK setting and an Sync All Cores multiplier of 32. That accomplished a cpu core clock of 4000Mhz and the expected 3000Mhz memory strap of the XMP profile of the kit.

But what I found in the OS was that I had my all core boost again at the normal system clock of 4000Mhz. But the BIOS says to use if possible a standard front side bus frequency of 100Mhz and achieve the desired core clock and memory strap settings with a higher multiplier. This is how I had the system set up previously. 100 Mhz BCLK and 42 multiplier for 4200Mhz cpu clock and the XMP 3000 Mhz memory strap.

When I did that though I lost my all core boost again and was back again with the original problem of only two cores boosting to 4000Mhz and the rest at 3800Mhz. All the BIOS settings were set by default to Auto just as before.

As soon as I went back to the BLCK of 125Mhz and the multiplier of 32, I got my all core boost back again at 4000Mhz. So I set up a 34 Sync All Cores multiplier for a derived 4250Mhz cpu core clock and the XMP 3000 memory profile. I was able to get my same Vcore voltage back by setting a manual voltage of what I was running previously with an Auto with Offset voltage setting.

So once again I am boosting all cores at my desired core clocks.

So, there is definitely a difference between what the cpu exports in the MSR registers to the OS when achieving the desired cpu Turbo Boost settings via a BCLK of 125Mhz and one of 100Mhz. The 100Mhz BCLK setting prevents a all core Turbo Boost with the default intel_pstate scaling driver and performance governor. So for anyone that lost their all core Turbo Boost with the new 4.15.0-20 kernels, this is the way to get it back.

[Edit] Addendum. What this accomplished was reducing my BLC cpu task completion times from 51 minutes down to 32 minutes. Now the Intel system can run the BLC cpu tasks as fast as the Ryzen systems.]

And finally a i7z screenshot showing the proof.