Turbo boost processors: lower base frequency and higher max frequency or higher base frequency and lower high frequency?

Question

I am about to buy a new Macbook pro and am a bit puzzled as per the processor choice: I am thiking of these two options: 1. i5 at 3.3 gHZ, turbo boost to 3.7 gHZ 2. i7 at 2.5 gHZ, turbo boost at 4 gHZ

There is a huge gap on the turbo boost range, with the i7 "turbo boosting" on a 1.5 gHZ range...

Most of the time I would use the computer for office applications (web browsing, text editing, etc.), with a heavy emphasis on multitasking (tens of tabs open at the same time, tens of document). And some of the time I would do a bit of gaming, when plugged to an outlet (so power consumption an non-issue).

I am more concerned with the gaming bit (I know very well: this is a not a gaming rig, but I may still be interested in using it this way some of time): am I right to assume to that the 4 gHZ on the i7 will not be available all the time and that I may therefore be better of with the i5, even though it only goes up to 3.7?

Any other take on my issue :)?

Answer 1

Processor performance can be a tricky thing to judge. A higher clock speed does not necessarily mean better performance. And neither does more cores.

This is especially true when comparing between different types of processors or different families. And especially when looking at enterprise class Xeon chips

So while an i5 3.3Ghz chip would normally be faster that a i5 2.3GHz chip, it does not mean that a i7 2.5Ghz is slower. (assuming that you are comparing within the same generation of chip).

Intel use the i5, i7 etc. branding to indicate the class of the chip. So generally an i7 chip is going to be faster than an i5 chip (again assuming that you are comparing within the same generation of chip).

The turbo boast is a facility to boost the performance of a chip for a short period if it is not using all of it's cores. So if a 4 core chip is only using 2 cores, then it can boost the frequency of these 2 cores for a short while. And if it is only using 1 core then it can boost it even further. But this generates extra heat and if the processor starts to get too warm then it will gradually reduce the level of boost until this is under control. So normally this is just a short term boost used in small spurts.

You don't say, but I assume that the two processors you want to compare are the;

• I5-7287U
• I7-7660U

The best way to do this is to use performance benchmark data. I normally use passmark but I could not find the comparison on there, but I have found this comparison, although it is in German you can use google translate, although the figures are self explanatory

http://www.technikaffe.de/cpu_vergleich-intel_core_i5_7287u-687-vs-intel_core_i7_7660u-681

This shows different benchmarks for single and multi threads and shows that the i7 is between 6% and 1% better, depending on the benchmark.

The difference in price is around 115 USD (list price), but as you can only get as part of a laptop then of course the price of the whole laptop might be different.

In the end only you can decide if the price difference is worth it for you.