Apr 202011

My cousin in Australia had an issue with his new quad core i7 Sandy Bridge HP DV7-6011TX laptop running uncomfortably hot when playing an old PC game on it. I had a similar problem with my Toshiba Portege r705-p25 Core i3 350 Arrandale laptop in Google Earth Flight Simulator with 3D terrain and objects maxed out, so we started looking for solutions and exchanging results to discover the best way to keep our laptops cool and quiet when we don’t need superfast performance.  

In his case of the old game it seems that the new Sandy Bridge laptops with quad cores (or even dual cores with four “virtual” cores including the older Arrandale series) get very warm and noisy running legacy applications designed for the old single CPU/single core technology. This gets even worse with aggressively designed turbo mode on fastest core i7, so when an old game enters the bridge and requests all hands on deck and full steam ahead without really needing all that computing power, the CPU speed, power utilization and the resulting heat goes beyond the comfort level. A forum discussion about a similar issue suggested underclocking, however, that was easier to do with older technology CPUs. Most online articles I read suggested that hardware overclocking and in our case underclocking is nearly impossible on Arrandale and Sandy Bridge laptops (excluding the top models with extreme quad Core i7-2920XM mobile CPU with unlocked Turbo multipliers that sell for an arm and a leg). Fortunately, that wasn’t the only option.

We started tweaking the power plans to try to get the laptops to run cooler. I usually run my laptops in “Balanced” power plan, which takes advantage of Intel SpeedStep technology and keeps the CPU at the lowest possible speed and power consumption when idling, but when the load and demand increases it instantly speeds up to appropriate speed (on my laptop the slowest idling speed is 929 MHz, and it goes up in increments of 136 MHz all the way to the peak of 2266 MHz). On the other hand, “High Performance” plan constantly runs your CPU at its peak speed, but this produces a lot of heat and consumes a lot of power with minimal benefit (1-3% performance improvement) when compared to the automatically adjusting Balanced Power Plan.

So, to get the laptop to run cooler I first switched to Power Saver plan and got some results – the laptop was not heating up as much in Flight Simulator mode, with the fan not being as noisy as before. When flying while in “High Performance” or “Balanced” scheme, the CPU core temperatures remained around 85˚C [degrees Celsius] (around 185 Fahrenheit) most of the time during a flight session and the CPU speed in “Balanced” mode barely ever went below the peak 2266 MHz, so there’s virtually no difference between these two plans under heavy load. But when I switched to Power Saver scheme, the core temperature remained around 70˚C (160 Fahrenheit) most of the time and the CPU frequency varied between 929 and 2266 MHz, mostly in 136 MHz increments, trying to stay in lower numbers, however, the core temperatures still sometimes shot all the way up into the mid 80s when the load on the CPU/GPU was heavy, and the fan got loud as well. Although I wasn’t very happy with the Power Saver plan and I continued to tweak more settings, this did the trick for my cousin. He tested it on his Core i7-2630QM laptop with a program he wrote:

On HP recommended settings
– Count to 50,000 in 19.0 s
– Delta temperature 11 degrees (51 to 62) in 19s (and it would continue rising)
– Fan starts after 5seconds or so

On Power Saver plan
– Count to 50,000 in 1min 01s
– Delta temperature 2 degrees (50 to 52) and stays stable…
– No fan start

The only change between the default HP and Windows “Power Saver” plan was the ‘PCI Express /Link State Power Management’ setting: HP plan is set to ‘Moderate’, while in the Power Saver plan it’s set to ‘Maximum power savings’.

His results on Power Saver plan were good enough with silent fan and lower CPU core temperature (less than 1/5 of the original temperature rise) with a significant loss of speed (3x slower). However, the desired result, much cooler laptop has been achieved, and when playing old games programmed for a much slower processor, such a decline in performance won’t be noticeable at all.

However, my results were not cool enough for my Google Earth Flight Simulator, which still kept my laptop hot, so I went further and created a new power scheme, called it Low Heat and set the following variables:

Processor Power Management:
Minimum Processor State: 2% (from 5% default – probably insignificant)
System Cooling Policy: Active – on both battery and plugged in (hence the name of the plan)
Maximum Processor State: 35% (just a SWAG – scientific wild ass guess)
Intel (R) Graphics Settings:
Intel (R) Graphics Power Plan at Maximum Battery Life (instead of Balanced default, or Maximum Performance).

The results may vary between laptops with a discrete (separate) graphics card and a Core i3 with integrated GPU, and one may be able to achieve longer battery life and less heat with lower utilization.

These throttled-down settings achieved the desired result – laptop remains relatively cool and the fan isn’t noisy. When flying in Google Earth Flight Simulator, the CPU speed remains at 929 MHz, and the CPU core temperatures remain around 60˚C (140 Fahrenheit) now, which is up to 25˚C (about 45 degrees Fahrenheit) less than under load in other power plans.

Later I tried changing the percentage to which I throttle down the Maximum Processor State and noticed no benefit under 45%. Above 46% the CPU speed gets a bit higher when under load, while lowering the percentage much lower than 45% (In my experiments I even went as low as 5% and 10%) had no further influence on heat or load on each core while doing processing intensive tasks, so for now my “Low Heat” power plan is set to 45% Maximum Processor State, both on battery and when plugged in.

Update May 17: I just saw a new “Super Saver” plan on a Lenovo B560 laptop I just reviewed and it has both minimum and maximum processor state set to 0%. I don’t know how it affects system temperature and performance, but judging from my previous experiments, it may not change much from the settings I have specified above in my “Low Heat” plan.

If you start playing with these settings, do yourself a favor and create a new plan and change them there, so you can always go back to a factory default plan. Also, don’t forget to revert to a ‘normal’ plan if you’d rather have a fast than a cool laptop. I often use the Low Heat plan when I write emails or these posts because that’s when speed doesn’t matter. Unfortunately, throttling down of the CPU doesn’t seem to add as much to battery life as I expected, so if anybody achieved even more with battery life, please let me know.

  2 Responses to “Cooler Laptop by Simple Underclocking”

  1. turboboost disable in i7 processor significantly reduces the heat output, with out affecting performance

  2. Throttling down the processor lessened heat on my ever-heating laptop.

    Minimum = 0%

    Maximum = 20%

    Plus, It also maximised the old battery, from 30 minutes to 4 HOURS.

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