MP 1,1-5,1 Strange fans

[iChan]

I'm running a 4,1>5,1 with dual 3.33GHz X5680s and I've noticed some strange issues and resetting the SMC didn't help.

(Just to confirm, I reset the SMC by unplugging, then holding power button for 5 seconds, right?)

I have iStat and MFC both installed and I'm doing the "yes > /dev/null" x 24 in Terminal to max out the CPU usage. However, both the CPU fans stay at 1110 - 1115 RPM and never budge even when the CPU temp gets as high as 86DegC.

Even when idle, the CPU fans are in this range. I can control the fans just fine with both iStat and MFC, but auto modes don't seem to work at all.

What is the maximum rated temperature of this CPU? The X5690 is 78.5°C according to Intel so there is something really abnormal going on with my fans.

Any advice?

EDIT:
Here's my hardware overview...

 

[iChan]

Just did a deep forum dive and found out that the fan speeds are completely normal for a dual CPU system.

I retried the test and the fans did eventually spin up.

Crisis averted.

 

[h9826790]

I'm running a 4,1>5,1 with dual 3.33GHz X5680s and I've noticed some strange issues and resetting the SMC didn't help.

(Just to confirm, I reset the SMC by unplugging, then holding power button for 5 seconds, right?)

I have iStat and MFC both installed and I'm doing the "yes > /dev/null" x 24 in Terminal to max out the CPU usage. However, both the CPU fans stay at 1110 - 1115 RPM and never budge even when the CPU temp gets as high as 86DegC.

View attachment 1748816
Even when idle, the CPU fans are in this range. I can control the fans just fine with both iStat and MFC, but auto modes don't seem to work at all.

What is the maximum rated temperature of this CPU? The X5690 is 78.5°C according to Intel so there is something really abnormal going on with my fans.

Any advice?

EDIT:
Here's my hardware overview...
View attachment 1748821

For your info, 78.5 is the T-case max, not T-diode max. Diode temperature is much higher than case temperature.

 

[KeesMacPro]

Just did a deep forum dive and found out that the fan speeds are completely normal for a dual CPU system.

I retried the test and the fans did eventually spin up.

Crisis averted.

The Boost fans run both at ~1100 rpm ,when set to auto .
Generally the default Mac settings are more focused on low noise than on low Temps = they ramp up when things get quite hot .

What could lead to irregularities/conflicts is running iStats and MFC at the same time.

(Just to confirm, I reset the SMC by unplugging, then holding power button for 5 seconds, right?)
Unplug the power lead, wait ~10 sec, plug it in wait ~5 sec and power it on.