Xeon e5 Turbo Boost Question

[PowerPie5000]

This is hopefully a quick one.... My Xeon E5 1660 V2 is supposed to have a max turbo boost of 4.0GHz, but the highest I've seen it reach so far is 3.9GHz (very rarely) and it usually tops out at 3.8GHz 90% of the time. Another strange thing is some utilities detect it as a Xeon E5 1620 V2 which has a max turbo of 3.9GHz (although that is a 4 core chip and mine is a 6 core).

The BIOS detects the CPU correctly as a Xeon E5 1660 V2 (6 cores/12 threads). The motherboard is an Asus Z9PA-U8 with the latest BIOS version (not too sure about the ME firmware part of it though?).

Does anyone have any ideas on what could be happening? Cheers

[CAT-THE-FIFTH]

My Xeon E3 1230 V2 tends to not be able to hit its max 3.7GHZ consistently and its down to the TDP limit.

[PowerPie5000]

My Xeon E3 1230 V2 tends to not be able to hit its max 3.7GHZ consistently and its down to the TDP limit.

I think I saw something in the BIOS about it having a 156W power limit (default setting)... I'll have to double check. Surely it wouldn't reach it's TDP limit by boosting to it's max on a single core? I've never seen mine hit the advertised 4GHz. I've had a Xeon E3 1240 V2 paired with a cheap MSI B75 board that had no trouble boosting to 3.8GHz and my i7 4790k consistently hit 4.4GHz too!

Maybe it's just constantly running a few cores all the time?

[PowerPie5000]

The C-State options in the BIOS were disabled for some reason, so I enabled the options up to C-state C6 (default optimised setting) and now the cores occasionally boost to 4GHz... Not as often as all the previous Intel CPU's I've had though. Anyway, it seems all is working as intended as far as I can tell so no need to start messing around with the ME firmware etc.