A few posts ago i shared my Story about Turboboost unlock not working with an e2667v2 on an Asrock x79 xtreme3.
I now have a theory why that is:
I recently got an Asrock Z97 Anniversary with a non-K i7 4790 for free. I is a Multiplier-locked CPU the same way as the Xeon.
With the original BIOS on that board i was able to set the all-Core Turbo boost clock to 4Ghz either by using a fixed clock, but also with speedstep enabled. But the BIOS would not detect the nvme SSD, so updated it to the latest one.
With the new BIOS, the Turbo settings in BIOS as well as allcore Fixed Multiplier would have no effect in windows.
This is a know issue for LGA1150 mainboards using a CPU-Microcode above V7:
https://www.reddit.com/r/overclocking/comments/szco3g
Apparrently when Intel released all those Spectre and Meltdown Mitigations, they also added new microcode for Haswell, Broadwell that was silently disabling the turboboost unlock Loophole and slowing down turbo boost behaviour with the pretext of making the CPU "safer" as some rowhammer-like Cache-exploits worked better on CPUs with higher, almost unstable clocks.
My theory is that the same has been the case fo LGA2011 / x79 and Ivybridge-E, which is why my turbo boost settings don't work anymore on my x79 motherboard.
Both boards had an official BIOS update from Asrock in August 2018, which i have been using since both fixed or introduced NVME support officially.
I already patched the Z97 one with the old V7 microcode by using UBU. Now Turbobosst unlock is working again for the 4790.
I currently don't have access to the x79 system, but i will definitely try that later. Does anybody have experience with UBU and Microrode rollback on the x79 Platform?
I suppose most people in this thread did not come across this Problem because most x79 motherboards didn't have mid 2018 BIOS Updates or after Intel introduced the Microcode updates in early 2018 for that matter.
My 2667v2 is insanely well binned too.
It will only draw 95Watts at 8x 3,7Ghz and stay below 56°C while my 6-Core 1650V2 with half as much cache needed 150Watts at 4.2Ghz and was hitting 75Degrees on the same board and cooler. So the Cores of the 2667v2 MCC DIE were almost twice as efficient as the 1650v2s LCC DIE Cores.
Seeing the 4790 does also draw around 90Watts with Turboboost unlock and 4.1ghz allcore, one could say that twice as many ivybridge Cores and a huge 25mb cache equal half as many Haswell Cores with only 8M. I am quite impressed. Dunno about games, but i suppose in modern games more than four cores is more important than Haswell IPC.
Don't have the 1680v2 myself, but the 1000 series xeons seem to be of a lower bin considering the 1680 has 300mhz lower baseclock and 100mhz less turbo at the same 130W TDP as the 2667v2. A shame that the latter is locked and doesn't have straps available- would be the perfect LGA2011 CPU.