Expected buyers of 2018 MacBook Pro were met with a dilemma shortly after the device was launched. Reports were found that the machine experienced heavy throttle and wild inconsistent performance under heavy, sustained load, especially when both the CPU and the GPU were charged at the same time.
Early speculation suggested that this was due to the inability of the MacBook Pros thermal management system to support the demanding Intel Core i9 CPU. But Apple quickly announced that there was an error in the MacBook Pros firmware that affected the heat treatment system. A firmware update was released earlier this week. Here's Apple's public statement about the problem:
After extensive performance testing under a variety of workloads, we've found that there's a lack of a digital key in the firmware that impacts the thermal management system and can drive the clock rate below high thermal loads on the new MacBook Pro. A bug fix is included in today's MacOS High Sierra 10.13.6 additional update and recommended. We apologize for any customer who has experienced less than optimal performance on their new systems. Customers expect the new 15-inch MacBook Pro to be up to 70% faster, and the 13-inch MacBook Pro with Touch Bar can be up to 2X faster, as shown in the results on our site.
We are dedicated once a week to restore all the references we made for our review to see how performance was affected by the firmware update. We also wanted to see side-by-side comparisons of clock speeds before and after the update.
In a test, we artificially pushed all CPU cores for maximum utilization by generating 12 processes with "yes> / dev / null &" in Terminal. We measured the CPU clock rate in Intel Power Gadget Utility. First, we let the processes run for five minutes before taking a snapshot of the time-frame graph you see below. The first step MacBook Pros Core i9 CPU was spread well before that point.
We repeatedly repeated GFXBench Metal's 1080p Manhattan screen GPU benchmark while the processes were still running. We took the picture of this test during the third successful course of the reference point.
We did this in a temperature controlled room (72 degrees Fahrenheit). We ran the tests once before you installed the firmware update and again after using it.
In our post-firmware test, a 3.5 GHz clock rate was maintained even when all the cores were fully utilized for a long time. This was definitely the performance that Apple promised when announcing the new MacBook Pro setup, and we're excited to see that the firmware update has made it a reality.
Things get muddier when the GPU is also fully taxed. At that time, the CPU is flushed to as low as 2GHz. However, performance is consistent, which is essential for 3D modeling and many other workflows that were hampered by the wildly fluctuations we saw before the update.
Remember, this was an artificially produced worst case scenario that is more serious than almost all actual usage cases, but MacBook Pro still can not fully drain the potential of both the CPU and the GPU at the same time. This is not surprising given the portable form factor. It is a compromise for portability.
We performed many more tests, and they all told exactly the same story behavior are now common and as announced in the vast majority of cases, but some extreme scenarios involving both the CPU and the GPU still lead to gas damages, but with more consistent clocks. The above test only illustrated the most clearly.
We've updated our review with these revised benchmarks, as the latest tests have delivered different results after the update. In many cases, the results were not significantly different; This is due to the fact that many of our standard rating interfaces measure short bursts of explosion instead of sustained performance over a period of time. The error has only affected tests as measured by the latter scenario.
After the update, MacBook Pro is now easier to recommend to most creative professionals, developers and researchers, provided they can afford it and want to prioritize a balance between performance and portability, that is.