Intel Core i3-8121U vs Intel Core i5-6400

Processor comparisons   20-01-2022
   For example you are thinking about choosing a CPU, you will be able to make a choice after reading the comprehensive tests Intel Core i3-8121U vs Intel Core i5-6400 and decide which is better for games or simple use for video editing, streaming, rendering, programming, machine learning. Here is useful information from real streaming and video editing tests or many benchmarks. A thorough review of all the technical characteristics, so that it can be easier to understand, is summarized in the table.
   From the video comparison, you can get the results of parallel examination in special test applications like Gears 5, 7zip, Handbrake, PCMark 10, Dolphin Emulator, 3DMark, DaVinci Resolve Studio, World of Tanks enCore Benchmark, WPrime, UserBenchmark, Prime95, Blender, SuperPi, GeekBench 6, 5.2, Blender, Cinebench 23 (20, 15), PassMark, VeraCrypt, MATLAB, RealBench, Furmark, AIDA64.
   Gaming performance of CPUs in:

DOOM: Eternal
World of Warcraft: Shadowlands
Overwatch
Fortnite
Borderlands 3
Valheim
Last Man Standing
Valorant
Rainbow Six Siege
Assassin's Creed Valhalla
Fallout 76
Call of Duty: Modern Warfare and Warzone
Cyberpunk 2077
Grand Theft Auto V
Halo Infinite
Death Stranding
Red Dead Redemption 2
Apex Legends
Watch Dogs Legion

After reading the results of all benchmarks and videos, you already be able to figure out which CPU is better to buy for gaming Intel Core i5-6400 or Intel Core i3-8121U.

Summary benchmark results

As a percentage of the maximum value based on a sample from the entire base of all processors
Processor Benchmark

Core i3-8121U

51%

Core i5-6400

51%

Gaming performance
Summary result of all game benchmarks.

Core i3-8121U

51%

Core i5-6400

51%

For the maximum in this test, the results of the most powerful processor in the site database are taken. And of course, this is a server processor, on which no one will play games. Because this processor costs several tens of thousands of dollars. Therefore, if you think that the selected CPU has a small game result, look at the FPS that it produces in real games in the summary table below.
List of other games in which CPU comparisons were performed: PlayerUnknown's Battlegrounds (PUBG), Metro Exodus, DOTA 2A, Hitman 3, Shadow of the Tomb Raider, Horizon Zero Dawn, The Witcher 3: Wild Hunt, League of Legends (LOL), Counter-Strike: Global Offensive (CS GO), Control, Battlefield V, Half-Life: Alyx, Monster Hunter World, Ghostrunner, Microsoft Flight Simulator, Resident Evil 7 Biohazard, NBA 2K20, Forza Horizon 4.

Gaming benchmark

Fortnite	90.1	91.3
Valorant	102.4	103.7
Cyberpunk 2077	57.3	58.1
Apex Legends	96.2	97.5
Call of Duty Warzone	76.8	77.8
Overwatch	82.9	84.0
Red Dead Redemption 2	70.6	71.6
DOOM Eternal	51.2	51.9
Warzone	79.9	80.9
Assassin's Creed	86.0	87.1
Valheim	85.0	86.1

The numbers in this table indicate the maximum FPS that was received on the device with the corresponding processor. Depending on the configuration of the computer (RAM size and Video Card) and graphics quality settings (Ultra, Medium, Normal), the results may differ quite significantly. We recommend that you better study the results of the Cinebench, GeekBench and Passmark becnmarks.
The tested computers not only did they have different amounts of RAM and different video cards. But users also tested them at different screen resolutions: 2K, 4K or FullHD. Therefore, the game benchmark data is approximate. But all video cards met the average system requirements of games. To be sure exactly how much performance the processor will be in games, if you get acquainted with the benchmarks that are made with the same video card that is installed in your computer.

Power consumption

Core i3-8121U

200%

Core i5-6400

49%

To make a finishing decision on which processor is better, you should also consider the generation of its core. The newer the processor generation, the better its performance in games and benchmarks, as well as its energy efficiency. In this case the Core i3-8121U is more energy efficient than the Core i5-6400 since it has less power consumption: 15W vs. 65W. Power consumption is particularly important for laptops. Also, when choosing a processor cooling system, it will be useful to know its TDP. It is necessary to calculate so that the TDP data specified in the cooler specification is greater than the TDP of the compared processor.

Software benchmarks

If you plan to use the processor not only for gaming, but also for machine learning, programming, streaming, video editing or video rendering, then the main parameter for you is its performance in multi-threaded mode. In this mode, the processor uses all threads and cores that it has to the maximum to reach maximum efficiency. You will find out this data from the benchmark tables below. Before using the data from these tests, be sure to check whether the program you are going to use on your computer supports multi-threaded mode. Since there are still many programs that can use only one core to work, and all the benefit of multi-core mode are unused.
Cinebench 23, 20 an 15
The results of this benchmark show Single-threaded and Multi-threaded CPU performance

	Intel Core i3-8121U	Intel Core i5-6400
Cinbench 15 Single-core	139	140
Cinbench 15 Multi-core	305	497
Cinbench 20 Single-core	340	275
Cinbench 20 Multi-core	598	1061
Cinbench 23 Single-core	563	1001
Cinbench 23 Multi-core	2184	3997

Passmark
This popular benchmark displays Multi-threaded and Single-threaded processor performance

	Intel Core i3-8121U	Intel Core i5-6400
Single-Core	1939	1957
Multi-Core	4369	5167

GeekBench 6, 5.2
This benchmark shows Multi-threaded and Single-threaded processor performance

	Intel Core i3-8121U	Intel Core i5-6400
Single-Core	901	959
Multi-Core	2063	3221

Comparison of specifications

In the specification comparison table, the most helpful will be the release date of the processor and the possibility of overclocking it. The newer the processor, the longer it will last you. And the easier it will be to upgrade the system in the future. The same benefits from the presence of overclocking. When the processor can be overclocked, thereby increasing its performance, then it will continue to maintain maximum FPS in the newest games. It turns out that there is no longer a need to buy a new CPU to enjoy the games any longer. The savings are obvious!

	Intel Core i3-8121U	Intel Core i5-6400
Announcement date	July 07, 2018	April 01, 2015
Type	Laptop	Desktop
Socket	Unknown	LGA 1151
Core name	Cannon Lake	Skylake
Architecture	x86	x86
Generation	8	6
Turbo Frequency	3.2 MHz	3.3 MHz
Frequency	2.2 MHz	2.7 MHz
Cores	2	4
Threads	4	4
Bus rate	4 GT/s	8 GT/s
Bit	64	64
Lithography	10 nm	14 nm
Transistors count	1800 millions	2460 millions
Power consumption (TDP)	15 W	65 W
Memory type	DDR4-2400, LPDDR4/x-2400	DDR4-1866/2133, DDR3L-1333/1600 @ 1.35V
Max. Memory	32 Gb	64 Gb
Memory Frequency
Memory bandwidth	37.5 GB/s	34.1 GB/s
L1 cache
L2 cache
L3 cache	4 MB	6 MB
Overclocking	No	Yes
Supports ECC	No	No
Part number

In this comparison block, you should pay attention to the differences in clock speed and the number of cores. Here Core i5-6400 is 18% better than Core i3-8121U in terms of CPU frequency. Another difference is that Core i5-6400 has 2 more core than Core i3-8121U. Also keep in mind that high CPU frequency affects battery life through power consumption (relevant for laptops).

Result:
The number of parameters for which Intel Core i3-8121U is better: 6
The number of parameters for which Intel Core i5-6400 is better: 28
Although it should be realized that all the figures in the text above do not mean that taking them into account you should completely trust a simple quantitative comparison. Better to watch the testing video and read the reviews of of people who bought Intel Core i3-8121U and Intel Core i5-6400 before making a selection which of the processors to buy for gaming.

Intel Core i3-8121U - all data

• Cinebench r15 score
• Cinebench r20 score
• Cinebench r23 score
• GeekBench 6, 5.2 score

• Intel Core i3-8121U specs and review.

• Intel Core i5-6400 specs and review.