Specs, our gaming estimate and the graphics cards it pairs well with.
The Core i5-6400 is a E-tier gaming processor: #162 of 238 in our list, with 4 cores and 4 threads up to 3.3 GHz. At 1080p it can feed a card like the Radeon RX 5600 XT without a CPU bottleneck above 10%, and at 1440p a GeForce RTX 5050.
Updated October 3, 2026
Gaming index (Ryzen 7 9800X3D = 100) against the processors closest to it.
The Core i5-6400 scores 21 on our gaming index, where the Ryzen 7 9800X3D is 100. That puts it #162 of 238 processors we track, in E tier. It is slow by current standards, and recent games will often run well below what the graphics card can do.
It has 4 cores and 4 threads, boosting to 3.3 GHz. With 4 cores, the newest games will stutter or limit your frame rate, because they are built for six or more.
The Core i5-6400 uses the LGA1151 socket, so it fits motherboards with that socket. The fastest chips we track on the same socket are Core i9-9900K and Core i7-9700K, which would be a drop-in upgrade without changing the motherboard.
It is rated at 65 W. That is easy to cool; a decent tower cooler is enough, and the box cooler works on some models.
At 1080p, where the processor matters most, the Core i5-6400 can feed a card up to the Radeon RX 5600 XT before it starts to hold the card back by more than 10 percent. At 1440p the limit moves to the GeForce RTX 5050. At 4K, where the card does most of the work, it can keep up with the Radeon RX 9060 XT 8GB. The full list of graphics cards for the Core i5-6400 has the options for each resolution.
The Core i5-6400 is old or low power. Expect new games to run poorly, and look at an upgrade before you buy a new graphics card.
Graphics card performance index it keeps up with at each resolution.
The Core i5-6400 is a E-tier gaming processor: #162 of 238 in our list, with 4 cores and 4 threads up to 3.3 GHz. At 1080p it can feed a card like the Radeon RX 5600 XT without a CPU bottleneck above 10%, and at 1440p a GeForce RTX 5050.
At 1080p it can feed a card like the Radeon RX 5600 XT without a CPU bottleneck above 10%. At 1440p, a card like the GeForce RTX 5050 is a reasonable ceiling.