The other day, I checked my hard drives with DriveDx, one of the best SMART checking apps I have come across. Much to my surprise, DriveDx reported an error located in my iMac mid–2018’s Fusion drive. Given that the Mac is only a year old and the error was located in the SSD part of the device, I was a bit alarmed, so I went on and checked what exactly the error was about.
The reported SMART value was a “raw value”, not an assessment of the app, so that made it even more alarming. It as associated with the SSD’s temperature. At this point, it became clear to me how useful it is to have these system utilities on a Mac. True, Macs are robust machines that serve us for many years — I was a happy iMac mid–2011 user until last year, which made that Mac a seven-year-old tool. Had it not died on me, I would probably still have been using it today.
This, in my eyes, still new iMac seems more delicate to me. I have yet to hear its fans speed up to cool down the many electronic components inside. It didn’t even audibly cool the machine when my room reached brain-boiling temperatures of 36 Celsius in the heart of summer.
So, understandably, I wasn’t at ease when I read DriveDx’s report, which is when I thought I’d dig up a utility that checks out the many temperature sensors inside the machine and lets you manually speed up its fans — TG Pro. Now, TG Pro doesn’t just give you an easy read-out of temperature sensors and a brutal manual speed-up of the Mac’s fan(s). It lets you set a maximum temperature for all of the monitored components inside. Once that temperature is exceeded, the fans will start speeding up to keep components at the preset level.
While I’m typing this, I have set the TG Pro controls to “Auto Boost” and for the first time since I own this Mac, I hear the fans making noise. To get to this level of automatic temperature control, I put in a rule that reads that I want to let the SSD temperature to rise to a maximum temperature of 40 degrees Celsius and the surrounding temperature to a maximum of 35 degrees.
After a few minutes of leaving the keyboard alone, the fans returned to their usual silent low speed, but as soon as I started typing, the fans sped up again.
TG Pro allows for a lot of control of your Mac’s ventilation system and does everything to lengthen the lifespan of your Mac’s components, but you need to be aware of the risk it entails, which includes that you wear out your fan prematurely. That’s where TG Pro’s user guide or tutorial comes in handy. I would even advise not to use TG Pro for anything other than temperature follow-up — which is the setting “System” — before you have read that user guide and gone through all of its chapters.
I wouldn’t use the manual setting unless you know really well what you’re doing. It’s not that you will set the fans to a too low setting because TG Pro prevents you from doing that, but to a setting that’s causing more wear and tear than is absolutely necessary.
TG Pro lets you set the “attack” time for the Auto setting, as well as a percentage of the maximum speed the fan is going to be set at given the target temperature. For example, you can have a rule that says the fan should blow at 30% of its maximum speed as soon as your CPU gets hotter than 40 degrees Celsius.
By the way, Apple changed the temperature sensor in more recent iMac and MacBook models, but TG Pro’s developer found a safe way to let you control the fans on those models, nevertheless.
TG Pro is available at https://www.tunabellysoftware.com/tgpro/ for a retail price of €21.78.