I got the i9 model and was quite worried and was considering to exchange it for the i7 model as I read online that the i9 model performs worse than the 2017 model. As my friend got the 2018 i7 higher end model, I decided to run some quick test as I cannot find the results of i7 2018 vs i9 online so far. The test isn’t very comprehensive as it’s for my own reference, but it gives a rough idea of 2018 i7 vs i9 CPU performance for those considering returning.
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Cinebench CPU Test:
i7 Turbo Boost Enabled with force Max Fan: 921
i7 Turbo Boost Disabled: 835
i9 Turbo Boost Enabled with force Max Fan: 935
i9 Turbo Boost Disabled: 945
On the i9 the thermal throttling is making it difficult to even maintain its base clock speed of 2.9Ghz due to it keep boosting to approx 3.7-4Ghz right after cooling, before severely throttling again after 1-2 seconds. I figured that if I disable Turbo Boost, I can make it maintain at 2.9Ghz as it won’t boost and overheat. True enough, it maintained at 2.9Ghz at approx 80 degrees celcius. In fact as seen from the above results, the i9 without turbo boost performs better than with turbo boost enabled.
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HandBrake 4K Encoding Test:
Both the MacBooks are throttling to about the same GHz range. The estimated time on both MacBooks are very similar, with the i9 having slightly better estimate time (~1-2mins out of 28mins). I did not time the entire encoding as I didn’t have the patience*to wait for 28 minutes. However from my observation after performing this test several times, it shows that the i9 is slightly faster than the i7 model.
I also performed this test with turbo boost disabled expecting better estimated time. However the estimated time remained the same...
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After these quick test, I feel more assured that the i9 does not perform worse than the i7. As a result, I will not be exchanging my i9 to i7. It seems that Apple can improve the performance of i9 by simply updating the firmware to manually lower the max turbo boost speed so that the CPU doesn’t get excessively hot and throttle. Apple can run some test and find a sweet spot that the i9 CPU will not throttle excessively. This might lead to a much better performance as the CPU will be able to sustain at a higher clock speed as demonstrated when i9 without turbo boost performs better than with turbo boost.
The only disappointing thing is that I was expecting the handbrake encoding speed to be much better. My base mid 2012 rMBP*with i7 quad core has estimated encoding time of 50-60 mins. Intel’s latest hexacore CPU is only performing 2X better than a 6 year old quad core. I was expecting more...
