Most Intel Core processors have integrated core graphics cards. For example, the i5 8400 has a built-in UHD630 core graphics card. Although the performance is not strong, it is enough to light up the host and meet the needs of daily office, entertainment and some entry-level games. Simply put, you can use it without a discrete graphics card.
I5 8400 built-in nuclear display
The i5 9400F named after the new F suffix castrated the core graphics card. Without an independent display, it is impossible to light up the host and drive the display, so it must be used with an independent graphics card.
3. Different prices
I5 9400F boxed or bulk, the price is about 50 yuan cheaper than i5 8400. Because the UHD630 core graphics card is castrated, and the main frequency is slightly improved, the performance is stronger than that of the i5 8400, and the price is cheaper. If nuclear display is not considered, the i5 9400F is more cost-effective only from the relationship between performance and price.
4. Other explanations
It is worth mentioning that although some Intel ninth-generation Core processors have changed the traditional silicon grease heat dissipation to better welding, some shops in the e-commerce platform have adopted i5 9400F as the welding design. However, judging from the opening of i5-9400F, this processor is still not welded, and it still uses traditional silicone grease to conduct heat, which is exactly the same as that of i5 8400, so it needs attention.
I5-9400F still has thermal conductivity when silicone grease is used.
On the whole, there is not much difference between i5 9400F and i5 8400. The core shows castration, the main frequency is slightly improved, and the performance is relatively stronger. However, due to castration of the core display screen, the cost is lower and the price is cheaper than that of 50 yuan.
Second, the performance test comparison:
Test platform configuration:
Processors: Intel 9th Generation Core i5 9400F and i5 8400
Graphics card: RTX2080 8G
Motherboard: ASUS ROG Strix Z390-F game
Memory: 16GB DDR4 3200Mhz
Power supply: pirate ship RM750X
Because the performance of i5 9400F and i5 8400 is not much different, the theory of deviation test is of little significance. Let's simply look at the frame rate differences among GTA5, Watchdog 2 and killer 2 through the test platform.
According to the actual measurement of the game, at the highest picture quality 1080P, the leading range of the i5 9400F is about 2%-6% compared with that of the i5 8400, and the difference is very small, which belongs to the toothpaste upgrade and the CPU performance difference is very small. In fact, the i5 9400F can be regarded as a castrated version of the i5 8500, which is mainly recommended by users with independent display screens, and the performance is slightly improved and the price is lower by sacrificing the nuclear display.
Comparative summary:
Which is better, i5 9400F or i5 8400? If it is a stand-alone user, the nuclear display is of little use. In this case, i5 9400F can improve CPU performance and reduce cost by castrating the core display and increasing the main frequency, and the cost performance will be more prominent. If you are a beginner, you don't plan to go to the independent graphics card or you are not sure whether you need to upgrade the independent monitor in the future. In this case, the i5 8400 is more recommended, mainly because you can use it without the independent monitor at first, and it is more flexible to upgrade later.