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We tested the Core i5-6400, which is the entry model of the Intel sixth-generation (Skylake) Core i5 family. Let’s check how it performs!
The Core i5-6400 is a quad-core CPU with 2.7 GHz base clock, 3.3 GHz turbo clock, TDP of 65 W, and manufactured under 14 nm technology. It has no unlocked multiplier, which means it is not aimed on overclocking and the only way to make it work at higher clock rates is incrementing the reference clock if your motherboard allows it.
The direct competitors of the Core i5-6400 are the FX-8370 (with stock cooler) and the FX-8350 (with Wraith cooler) from AMD. So, we tested the performance of the Core i5-6400 against the FX-8350. We also included on the comparison the Core i3-6100, to check if the price difference between the two models is fair and if the Core i5-6400 is worth the higher price.
We ran the tests using an independent video card, the GeForce GTX 950 from Gigabyte (read this video card review here,) disabling the integrated video on the CPUs with integrated GPU. We make it for two reasons: first, the FX-8350 has no integrated video. Second, because we believe most people who buys a CPU on this price range will use it with an independent video card, since people who uses integrated video usually prefers a more inexpensive CPU.
Figure 1 unveils the box of the Core i5-6400 we used in our tests.

Core i5-6400 ReviewFigure 1: the box of the Core i5-6400

Figure 2 shows the box content: a simple aluminum cooler, the CPU itself, a small manual and a sticker for your case.

Core i5-6400 ReviewFigure 2: content of the Core i5-6400 box

Figure 3 gives a closer view of the Core i5-6400.

Core i5-6400 ReviewFigure 3: the Core i5-6400 processor

Figure 4 shows the bottom of the CPU.

Core i5-6400 ReviewFigure 4: the bottom of the Core i5-6400

Let’s compare the main specs of the reviewed CPUs in the next page.
[nextpage title=”The Reviewed CPUs”]
In the tables below, we compare the main features of the CPUs included in our review.

CPU Cores HT IGP Internal Clock Turbo Clock Core Tech. TDP Socket Price

Core i5-6400

4

No

Yes

2.7 GHz

3.3 GHz

Skylake

14 nm

65 W

LGA1151

USD 190

Core i3-6100

2

Yes

Yes

3.7 GHz

Skylake

14 nm

51 W

LGA1151

USD 125

FX-8350

8

No

No

4.0 GHz

4.2 GHz

Vishera

32 nm

125 W

AM3+

USD 185

Below you can see the memory configuration for each CPU.

CPU L2 Cache L3 Cache Memory Support Memory Channels

Core i5-6400

4 x 256 kiB 6 MiB Up to DDR4-2133 or DDR3L-1600 Two

Core i3-6100

2 x 256 kiB 3 MiB Up to DDR4-2133 or DDR3L-1600 Two

FX-8350

4 x 2 MiB 8 MiB Up to DDR3-1866 Two

[nextpage title=”How We Tested”]During our benchmarking sessions, we used the configuration listed below. Between our benchmarking sessions, the only variable device was the CPU being tested, besides the motherboard and memory, which had to be replaced to match the different CPUs.
Hardware Configuration

Operating System Configuration

  • Windows 7 Home Premium 64-bit
  • NTFS
  • Video resolution: 1920 x 1080 60 Hz

Driver Versions

  • NVIDIA driver version: 358.91

Software Used

Error Margin
We adopted a 4% error margin. Thus, differences below 4% cannot be considered relevant. In other words, products with a performance difference below 4% should be considered as having similar performance.[nextpage title=”PCMark 8″]
PCMark 8 is a benchmarking software that uses real-world applications to measure the computer performance. We ran three tests: Home, which includes web browsing, writing, light gaming, photo editing, and video chat tests; Creative, that includes web surfing, video editing, group video chat, video conversion, and gaming; and Work, which runs tasks such as writing documents, web browsing, spreadsheets, editing, and video chatting. Let’s see the results.
Core i5-6400 Review
On the PCMark 8 Home benchmark, the Core i5-6400 obtained similar performance to the Core i3-6100, and was 14% faster than the FX-8350.
Core i5-6400 Review
On the Creative benchmark, the Core i5-6400 was 8% faster than the Core i3-6100, and 18% faster than the FX-8350.

Core i5-6400 Review

On the Work benchmark, the Core i5-6400 was on technical tie with the Core i3-6100, being 11% faster than the FX-8350.
[nextpage title=”3DMark”]

3DMark is a program with a set of several 3D benchmarks. Fire Strike runs a “heavy” DirectX 11 simulation. Sky Diver also measures DirectX 11 performance, and is aimed on average computers. The Cloud Gate benchmark measures DirectX 10 performance, and the Ice Storm Extreme measures DirectX 9 performance and is targeted to entry-level computers, so we don’t ran it.

Keep in mind that we used a GeForce GTX 950 VGA in this test on all CPUs.

Core i5-6400 Review

On the Fire Strike benchmark, the Core i5-6400 obtained similar performance to the Core i3-6100 and the FX-8350.

Core i5-6400 Review

On the Sky Diver benchmark, the Core i5-6400 was 8% faster than the Core i3-6100, but was 5% slower than the FX-8350.

Core i5-6400 Review

On the Cloud Gate benchmark, the Core i5-6400 was 9% faster than the Core i3-6100, and was 13% slower than the FX-8350.

[nextpage title=”Photoshop CC and Cinebench R15″]

Cinebench R15

Cinebench R15 is based on the Cinema 4D software. It is very useful to measure the performance gain obtained by the presence of several processing cores while rendering heavy 3D images. Rendering is an area where a bigger number of cores helps a lot, because usually this kind of software recognize several processors (Cinebench R15, for example, can use up to 256 processing cores).
We ran the CPU benchmark, which renders a complex image using all the processing cores (real and virtual) to speed up the process. The result is given as a score.
Core i5-6400 Review
On Cinebench R15, the Core i5-6400 was 30% faster than the Core i3-6100, but 19% slower than the FX-8350.

DivX

We used the DivX converter, a tool included in the DivX package, in order to measure the encoding performance using this codec. The DivX codec is capable of recognizing and using all available cores and the SSE4 instruction set.
We converted a Full HD, six-minute long .mov video file into an .avi file, using the “HD 1080p” output profile. The results below are given in seconds, so the lower the better.

Core i5-6400 Review

On the DiVX encoding, the Core i5-6400 had a similar performance compared to the Core i3-6100, and was 27% faster than the FX-8350.

DVDShrink

DVDShrink is an old but still very useful program to “shrink” video DVDs that have more than 4.7 GiB of data to fit single-layer DVD media. We used it to compress the DVD of “The Lord of the Rings: The Fellowship of the Ring” DVD to 4.7 GiB. The results below are given in seconds, so the lower the better.
Core i5-6400 Review
In this test, the Core i5-6400 was 6% faster than the Core i3-6100, and was on tie with the FX-8350.

Media Espresso

Media Espresso is a video conversion program that uses the graphics processing unit of the video engine to speed up the conversion process. We converted a 1 GiB, 1920x1080i, 23,738 kbps, .mov video file to a smaller 320×200, H.264, .MP4 file for viewing on a smartphone. The results below are given in seconds, so the lower the better.

Core i5-6400 Review

Here the Core i5-6400 was 7% slower than the Core i3-6100, but 19% faster than the FX-8350.
[nextpage title=”Gaming Performance”]

Battlefield 4

Battlefield 4 is the latest installment in the Battlefield franchise, released in 2013. It is based on the Frostbite 3 engine, which is DirectX 11. In order to measure performance using this game, we walked our way through the first mission, measuring the number of frames per second three times using FRAPS. We ran this game at Full HD, setting overall image quality at “medium.”
The results below are expressed in frames per second (fps) and they are the mean between the three collected results.
Core i5-6400 Review
On Battlefield 4, the Core i5-6400 obtained similar performance to the do Core i3-6100, being 5% faster than the FX-8350.

Dirt Rally

Dirt Rally is an off-road racing game released in April 2015, using Ego engine. To measure performance using this game, we ran the performance test included in the game, in 1920 x 1080 (Full HD) resolution and image quality configured as “medium” and MSAA off.
The results below are expressed in frames per second (fps).
Core i5-6400 Review

In this game, the Core i5-6400 was 38% faster than the Core i3-6100, and 60% faster than the FX-8350.

Grand Theft Auto V

Grand Theft Auto V, or simply GTA V, is an open-world action game released for PCs in April of 2015, using the RAGE engine. In order to measure the performance on this game, we ran the performance test of the game, measuring the framerate with FRAPS. We ran GTA V at Full HD, with image quality set as “normal” and MSAA off.

The results below are expressed in frames per second.

Core i5-6400 Review

On GTA V, the Core i5-6400 was 24% faster than the Core i3-6100, and 13% faster than the FX-8350.

Mad Max

Mad Max is an open-world action game launched in September of 2015, using the Avalanche engine. In order to measure the performance using this game, we ran its intro, measuring the framerate with FRAPS three times. We ran the game at Full HD, with image quality set as “normal”.

The results below are expressed in fps and they are the mean between the three collected results.Core i5-6400 Review

In this game, all of the CPUs had the same performance.

Rise of the Tomb Rider

Rise of the Tomb Rider is an adventure/action game launched in January of 2016, based on Foundation engine. In order to measure the performance using this game, we ran the benchmark included on it, using Full HD resolution and graphics quality set to “medium”.
The results below are expressed in frames per second.
Core i5-6400 Review
Also on Rise of the Tomb Rider, the performance was the same on all CPUs.
[nextpage title=”Conclusions”]
Comparing the Core i5-6400 to its competitor, the FX-8350, we can say we have a technical tie on performance. On some tests the Intel CPU was faster, and on other ones the AMD model performed better. So, we can say both processors are goog choices for mainstream computers, for gaming or work.
However, comparing the performance of the Core i5-6400 to the Core i3-6100, which is a lower-end model and, thus, less expensive, things change a little.
When we tested the FX-6350, one of the conclusions we achieved was that it has a better cost/benefit ratio that the higher end model, the FX-8350. Regarding to the Intel CPUs, the conclusion is pretty much the same: on several games and programs, the Core i5-6400 is not faster than the Core i3-6100, which costs two thirds of its price.
It happens due to the higher clock used by the Core i3-6100 (3.7 GHz) compared to the Core i5-6400 (from 2.7 GHz to 3.3 GHz, typically 3.1 GHz at full load.) This clock difference is big enough to compensate the advantage of the four real cores of the Core i5.
Compared to the FX-8350, the Core i5-6400 performs similarly, but has the advantage of the significantly lower power consumption. On the other hand, the AMD model is a little less expensive, and has an unlocked multiplier.
Concluding, the Core i5-6400 is a good CPU, but it has a poor cost/benefit ratio due to its relatively low clock rate. Probably the Core i5-6500, which has a significantly higher clock (3.2/3.5 GHz) and costs only USD15 more is a better option. And if your priority is keep the low cost, the Core i3-6100 is a more interesting option.