Intel Core i5-8400 vs Intel Core i9-11900K

Intel Core i5-8400

The Intel Core i5-8400 is a mid-range 6-core CPU. The processor belongs to the Coffee Lake generation and was presented in September 2017. It does not support Hyper-Threading, which means it can run six threads simultaneously. The base clock rate is 2.8 GHz and the CPU can speed up to 4.0 GHz under high load. Despite belonging to the new generation of CPUs, the Core i5-8400 is manufactured in an improved 14nm process.

Performance

The processor offers a strong performance increase compared to the Core i5-7400 due to its two additional cores. Single-core performance has not improved significantly compared to its Kaby Lake predecessor. As a mid-range model, the Core i5-8400 should be suitable for demanding games and programs.

Graphics

The integrated Intel UHD Graphics 630 iGPU is supposed to offer higher performance as its clock rate has been increased by 50 MHz. The build is identical to that of the Intel HD Graphics 630. We do expect a performance improvement, but as a low-end solution it will probably only display current games smoothly at reduced details - if at all.

Power Consumption

Intel specifies the TDP with 65 watts. Therefore, well-dimensioned cooling systems should easily manage to deal with the created heat. We expect increased efficiency due to the higher performance.

Intel Core i9-11900K

The Intel Core i9-11900K is a high-end desktop CPU based on the Rocket Lake architecture. The CPU offers 8 cores and 16 threads clocked at 3.5 - 5.3 GHz (Turbo Boost 3.0 / TVB). With Turbo Boost 2.0, 5.1 GHz can be reached with a single thread. Using all cores, the CPU can clock up to 4.8 GHz. Adaptive Boost enables even higher multi-core frequencies (5.1 GHz all core Turbo) but uses a lot more power.

The TDP is rated at 125 Watt (PL1, power limit sustained load) but the PL2 is set to around 250 Watt for short term boosts (up to 56 seconds).

The Sunny Cove processor cores (known from the Ice Lake mobile CPUs) offer larger caches and an improved IPC (up to 19%). Furthermore, the chip also includes (partly) integrated WiFi 6E and Thunderbolt 4. The platform supports PCIe 4.0 and Intel DL Boost for AI acceleration.

The faster Rocket Lake-S CPUs also integrate a new Intel UHD Graphics 750 that is based on the current Intel Xe architecture (e.g. mobile Tiger Lake) and offers 32 EUs. In the 11900K, the GPU is clocked from 350 - 1300 MHz.

Performance

The average 11900K in our database is in the same league as the Ryzen 7 5800X3D, as far as multi-thread benchmark scores are concerned. Which is an impressive result, as of mid 2022, and good enough for any task imaginable including content creation and professional gaming.

Power consumption

This Core i9 has a 125 W TDP, also known as the long-term power limit. Intel lets PC manufacturers reduce that value somewhat if required, 95 W being the lower limit, which would result in lower clock speeds and lower performance. The reality is, an 11900K can be much more power hungry than either of the two numbers imply simply because of its sheer might but also because it is manufactured on an old 14 nm Intel process that makes for lower-than-average, as of mid-2022, energy efficiency.