Thank you very much
The 3.3 GHz setting sounds very reasonable, I am going to try that.
After lurking for a while, I have joined the forum. In case it is helpful to anyone, I have the same cpus (7551 ES 2S1905A4VIHF4) on a H11DSI-NT Rev.2 running very stable 24/7 at 3.3 GHz on linux. My settings run after boot are:
P0 - Enabled - FID = 21 - DID = 2 - VID = 51 - Ratio = 33.00 - vCore = 1.04375
P1 - Enabled - FID = 10 - DID = 2 - VID = 5C - Ratio = 16.00 - vCore = 0.97500
P2 - Enabled - FID = 60 - DID = 10 - VID = 61 - Ratio = 12.00 - vCore = 0.94375
Power draw at idle is 234W. Note that I also adjusted the max cpu power in the bios to 210W, although I don't think I have ever hit that.
I had a heck of a time getting these to post the first time. Finally, after resetting the cpus in the sockets and resetting the bios via shorting the MB jumper these were able to post.
One thing I had a problem with in overclocking was the cpu VRM temps. When running some benchmarks, such as NAMD, I would easily hit 90-95 C and would sometimes go high enough to get an overheat alarm and thermal throttle the cpu, which would require a reset with ipmi. I did several things to address this issue:
1. mounted a Noctua NF-A4x10 40mm fan on the VRM heatsink
2. put a fan pulling air in from the bottom of the case to exhaust at the top. This is the same direction that I have my cpu fans oriented in push-pull.
3. Added a fan blowing on the back of the MB close to cpu1 mounting bracket. This mounting position was already provided by my large case.
The first 2 got my VRMs down to around 85-90C during benchmards, while #3 got them below 80C. While this computer is not completely silent, it only emits a quite hum that is less than 30dB from where I sit right next to it.
As far as the fans go, I changed out all my fans for Noctuas, and they mostly spin at 400-600 RPM at idle and light loads. However, like many Supermicro boards, the H11DSI does not like low spinning fans and tends to want to keep ramping them on a loop, which will drive you buggy after a short while. I tried lowering the thresholds in IPMI via
ipmitool -I lanplus -H 192.168.1.239 -U ADMIN -P ADMIN sensor thresh Fan3 lower 200 300 400
However, this didn't complete solve the issue for me. In the end I grabbed a shell script that someone wrote (Sorry, but I forget who wrote this to give proper credit) for a Supermicro LGA2011 board and modified it slightly. This runs at boot and polls the temps and fans and makes adjustments. I haven't had any issues since with fan ramping at idle and it has worked well in ramping up the fans under load.
Hopefully, this is helpful to someone else.