SmcFanControl 2.2.2 and 12-core Mac Pro (picking the right fan to cool HDs)

Question

Hello,
quite recently I've moved from my previous Mac Pro 8-core (the earliest model) to the latest Mac Pro 12-core.
I've successfully used smcFanControl with my old Mac, and the fan names listed in the app's preferences were matching the fans listed by iStat and by smcFanControl in its dropdown menu. In the new Mac Pro there are more fans, not all of them match the names listed by iStat, and some names are "false friends". Please note though that all the fans listed by iStat show up also in the dropdown menu of smcFanControl
Here's the fans list in the preferences of smcFanControl, in this order:
CPU_MEM
IO
EXHAUST
PS
Here's the fans list in the dropdown menu of smcFanControl and in iStat (I'm using the capitalization and order used by iStat, smcFanControl uses always all caps and names "Power Supply" as PS, plus adopting another ordering):
PCI
BOOSTA
BOOSTB
Exhaust
Power Supply
INTAKE
Now, the mapping looks also weird. Here's the mapping tested by increasing the speed of each fan I can control via preferences:
CPU_MEM == PCI
IO == Power Supply
EXHAUST == EXHAUST == INTAKE
PS == INTAKE
BOOSTA and BOOSTB run always at identical speed, and their speed is usually slightly less than 2X the speed of either Exhaust or Power Supply, whichever runs faster. Anyway they don't appear to be controllable via smcFanControl.
Interestingly, the mapping seems to be related to the order of the fans in the dropdown menu of smcFanPro. The first four fans listed there are:
PCI
PS
EXHAUST
INTAKE
My main problem currently is that I haven't yet found a way to keep the HDs at about 40°C or slightly less as I used to do with my old Mac Pro, unless I increase a lot the fans speed, which on the other hand brings down the CPU and RAM temperatures at quite ridiculous levels (basically only a few degrees more than ambient temperature, about 30° these days). What's worse, I haven't found exactly which fan affects more directly the HD temperatures. Increasing only the speed of a single fan never seemed to be enough, unlike with the old Mac Pro.
So, here are my questions to anyone using smcFanControl 2.2.2 on a Mac Pro 12-core:
1) Do you believe I should reinstall smcFanControl to get the correct list of fans? Or is this a known issue? (please note that I started using the new Mac by using Apple's migration utility, so also smcFanControl was "copied" from the old Mac like all other apps) If I have to reinstall smcFanControl,do you know if I should clean/delete specific directories or files to remove the old fans list?
2) Do you know which fan cools down most the HDs? I have four HDs so all bays are used. I've looked around quite a lot but I haven't found any diagram showing the fans position inside the Mac's case
Thanks a lot in advance for your reply and best regards,
Giovanni
Message was edited by: gs_mac

Answer 1

Put a fan in lower optical bay blowing on the drives? just kidding though.
Some drives now like WD Black 1TB+ do run normally at 40-41*C and that is in part because they are now engineering parts to be safe at those temps to reduce on cost of cooling and going green which can have a huge impact on data and server farms by just 5*C warmer.
My WD 10K VRs run COLD as can be and always have.
My advice is set the rpm for all fans @ one speed and then have 2 or 4 profiles: default, medium, high and extreme. Default is 499 for one and 599 for others. 900 rpm is just about when fans can be heard. 1200 rpm for more active cooling and 1800-2000 rpm for high.
The idea is in part to prevent it from getting warm first and then the system kick up the fans. Harder to get heat out of the case once it is there.
I think you are trying to "over-control" just a bit.
Prefe ences are in ~/Library/Preferences or just delete all the profiles. It probably has an uninstall.
I trust Temperature Monitor (freeware)  or paid version (Hardware Monitor) a bit more than iStatPro.