Saturday, June 3, 2023

An article about the performance of compact laptops … or is the i7 really that good?


Among people who understand technology at a basic level, there is often an opinion that a computer is better, for example, in which the processor is not i5, but i7, the amount of RAM is not 8 GB, but 16 GB, etc.

In part, yes, this statement is true, but there are some contradictions, as they say the devil is in the details, this will be discussed in this article 🙂

Short description
The article will cover:

About the features of the interaction of laptops with energy-efficient processors
About comparison and test of energy-efficient processors i5 and i7 of the 8th generation
About the mythical superiority of i7 over i5 with the same number of cores and threads
Conclusions and tips for future laptop buyers
Applicants and testing methodology
It so happened that I had at my disposal several very similar laptops with different price tags and reviews about them. These were business models, without discrete graphics (an additional video card) and all these models were purchased for approximately the same range of programming tasks.

HP ProBook 430 G5 i5 8250u with 8GB RAM and 256GB SSD
Lenovo ThinkBook 13s-IWL i5 8265u with 8GB RAM and 256GB SSD
HP ProBook 430 G5 i7 8550u with 16GB RAM and 512GB SSD
HP ProBook 430 G6 i7 8565u with 16GB RAM and 512GB SSD
The average price for modern similar equipment is from 50 thousand rubles.

For comparative tests, I used the following software:

Operating system MS Windows 10 1909
CPUID HW Monitor for monitoring temperature and power consumption
Corona Benchmark 1.3 to test performance under continuous load
All laptops have been updated to the latest drivers available on the manufacturer’s official websites.

I must say right away that for tests I specifically excluded such well-known programs as Cinebench R15 and R20, PCMark 10 and others. Such tests have already been repeatedly conducted and are available on the Internet, and most of these programs show a clear superiority of i7 over i5, but do not reflect reality.

Features of laptop processors
Among people associated with computers, it is not uncommon to hear such words as hyper-trading, multi-threading, turbo-boost, and in general, most of them understand how it works.

The models selected for the test on board have i5 8250U/8265U and i7 8550U/8565U processors.
General features of these processors:

Processor Indices
The numbers listed after the processor line. In our case, these are 8250 and 8550 related to the 8th generation of Intel processors. And 8265 and 8565 are generation 8+, we can say that 9, since after the 8+ generation of energy-efficient processors, Intel had a transition immediately to the 10th generation.
The letter U after the processor index
Means that this is an energy efficient processor, usually limited in power to 15 watts, indicated in the specifications by the TDP item. There are also processors with the letter H, they are usually limited in power to 45 watts. In some cases, this parameter is increased by the laptop manufacturer, for example, in MSI Prestige.
The base frequency of the processors
i5 has 1.6 GHz per core, i7 1.8 GHz per core. We can say that the i7 is superior to the i5, but this is not the case, since these processors have a turbo boost and can allow higher frequencies in terms of power.
Turbo boost
Functionality that allows the processor to operate at a frequency higher than the base. Divided into short and long, where a short (default 28 seconds) increases the power limit up to 90 watts. Long-term limits the power to 15 watts.
A mechanism to protect the processor from overheating. There are two types of throttling, one in terms of power, described above and depends directly on the turbo boost, and the second depends on the temperature of the processor. Most often, throttling occurs at a processor temperature of 95-100 degrees of the processor and is caused by a sharp decrease in the voltage and frequency of the processor. In some cases, laptop manufacturers lower this limit to 90 degrees or less.
Multi-threading/Hyper-threading Processor
functionality that splits the core into two logical threads, allowing for a performance increase of up to 30%, provided that the program supports multi-threading. For example, compiling a project in Microsoft Visual Studio for programmers.
Laptop Testing
Average performance

Notebook average performance was measured using Corona Benchmark 1.3 software and displays an average of ray/sec over 5 test runs. There was a pause of 30 seconds between each run.

Each run was about 7 minutes, which canceled out the laptop performance difference in a short turbo boost and reflects the performance under a longer high load. The difference between the processors is at the level of error. The frequency on all 4 processors was kept at about 2.2 GHz per core and was limited in power to 15 watts.

Time elapsed
In addition to the beams, Corona Benchmark 1.3 software displays the amount of time spent per run.

In terms of average time, the difference is also at the level of error, but there is a certain pattern and it can be seen that the i5 8265U and i7 8550U are slightly better than their counterparts. This pattern is quite clear and I will talk about it later.

Temperature on the processor during testing

To measure this indicator, I used CPUID HWMonitor and took the temperature value under the lid (CPU package indicator) at about 3 minutes of each run.

The results show the cooling efficiency of each laptop, in addition, we can make sure that there is no processor throttling. Based on these indicators, we can assume that the laptop from Lenovo can keep high frequencies for a longer time in a short turbo boost.
Temperature on the processor without load

This indicator was measured after the end of 5 runs ~ 1 minute after the end of the test, it once again reflects the efficiency of cooling systems for different laptops, but the impact on the overall performance in a long load is minimal.

As a conclusion
According to my tests, the difference between processors for i5 8250U/8265U and i7 8550U/8565U laptops is at the level of error, and after the end of a short turbo boost, they become approximately the same performance. Unfortunately, I didn’t have laptops with 10th generation Intel processors on the test, but I’m sure that the performance difference after the end of a short turbo boost between the i5 10210u and i7 10510u in the same laptop models is about the same, that is, at the level of error .
However, the difference in price for laptops of the same models, but with different i5 and i7 processors with the same number of cores and threads, averages about 10 thousand rubles.

If we talk about performance in a short period of time (about 30 seconds), then on paper the i7 really looks better, but it all depends on the system cooling. In the tested models, the model from Lenovo showed higher frequencies in the turbo boost, due to a more thoughtful cooling system and an aluminum case.

I think that overpaying for the i7 sticker in this case is unjustified and makes sense only if the i7 model outperforms the i5 model in terms of the number of cores and threads.

Of the interesting models of processors for laptops from Intel, I note the i7 10710u, as it has 6 cores / 12 threads on board and significantly outperforms the younger models, as well as the i5 1035G4 with a new technical process that allows you to get a higher frequency with the same limitation of 15 watts processor, and therefore performance.

In this article, I didn’t mention AMD’s laptop processor lines because I didn’t meet them, but judging by the reviews on the Internet, they outperform Intel solutions and it would be interesting to check both the 3rd and 4th generations of Ryzen processors.

I will be glad to feedback and your comments under the article.


Please enter your comment!
Please enter your name here



Related Stories