As iterated earlier, to ensure we get the CPU cranked up the max and to record its probable worst operating temperatures, we got both an the older MacBook Pro (MBP) and newer MBP looping Cinebench 11.5 and used smcFancontrol to monitor the processor's core temperatures and fan speed. It took about three to four loops before we noticed the temperatures plateaued and the fan revving up its RPM. Once that was achieved, we noted the highest temperature and current fan speed.
To keep things in perspective, we've also tested an Intel Core i7-620M equipped Acer Aspire Timeline X 4820TG, which is the same processor that the newer MBP uses. This should give us a pretty decent comparison of how the new and old MBPs fare as opposed to similarly equipped thin and light notebook such as the Acer Timeline X.
As you will see, the results are pretty interesting. The older MBP running Intel's Core 2 Duo processor had a lower maximum operating temperature than the newer MBP, though it's still quite high. Fan speed was also pretty average, peaking at 2800RPM mark, where the usual default speed is just 2000RPM. The newer MBP however recorded a much higher fan speed of 4800RPM at peak operating temperature, which was also higher at close to 100 degrees Celsius. This left us a tad worried, especially when the Acer notebook experienced a high of 71 degrees Celsius.
However, we did note the Acer notebook's fan speed noise at maximum loading was pretty loud. The newer MacBook Pro was noticeably quieter even at the 5000RPM range. Unfortunately we weren't able to get any data of Acer's fan speed as the sensor wasn't detected by the various utilities we've tried. As for the difference in temperatures between the Acer notebook and the Apple MBPs, we're guessing the better (and noisier) fan of the Timeline X and its direct exhaust system allows for better overall cooling compared to the MBPs, which had to work around the design aspects (the hidden fan exhaust and perhaps even quiet operation which could have been another design parameter).
Thankfully, the high temperatures of the notebooks do not impede or degrade the processor performance, as both the Intel Core i7 and Intel Core 2 Duo processors have a high temperature threshold, which means that even at 100 degrees Celsius, the notebook will function just fine. Whether or not you end up with a toasty lap or burnt table however, is another matter all together. More on this aspect on the next page.