Core i5-6400T vs Core i5-2550K

Both the Core i5-6400T and Core i5-2550K share an identical 4-core/4-thread configuration. Boost clocks reach 2.8 GHz on the Core i5-6400T versus 3.8 GHz on the Core i5-2550K — a 30.3% clock advantage for the Core i5-2550K (base: 2.2 GHz vs 3.4 GHz). The Core i5-6400T uses the Skylake (2015−2016) architecture (14 nm), while the Core i5-2550K uses Sandy Bridge (2011−2013) (32 nm). In PassMark, the Core i5-6400T scores 4,243 against the Core i5-2550K's 4,228 — a 0.4% lead for the Core i5-6400T. Cinebench R23 multi-core: 2,200 vs 4,058 (59.4% advantage for the Core i5-2550K). Geekbench 6 single-core — the metric most relevant to gaming — records 950 vs 707, a 29.3% lead for the Core i5-6400T that directly translates to higher frame rates. Multi-core Geekbench: 2,600 vs 2,010 (25.6% advantage for the Core i5-6400T). L3 cache: 6 MB on the Core i5-6400T vs 6144 kB (total) on the Core i5-2550K.

The Core i5-6400T uses the LGA1151 socket (PCIe 3.0), while the Core i5-2550K uses LGA1155 (PCIe 2.0) — making them incompatible on the same motherboard. Maximum memory speed reaches DDR4-2133 on the Core i5-6400T versus DDR3-1600 on the Core i5-2550K — the Core i5-6400T supports 28.6% faster memory, which can translate to measurable gains in memory-sensitive workloads. The Core i5-6400T supports up to 64 GB of RAM compared to 32 GB — 66.7% more capacity for professional workloads. Both feature 2-channel memory with ECC support. Both provide 16 PCIe lanes. Chipset compatibility: H110,B150,H170,Z170,Z270 (Core i5-6400T) and Z77,Z75,Q77,H77,Q75,B75,Z68,P67,H67,Q67,B65,H61 (Core i5-2550K).

Virtualization support: VT-x, VT-d (Core i5-6400T) vs Yes (Core i5-2550K). The Core i5-6400T includes integrated graphics (HD 530), while the Core i5-2550K requires a dedicated GPU. Primary use case: Core i5-6400T targets Budget. Direct competitor: Core i5-6400T rivals Core i3-7100.

The Core i5-6400T launched at $192 MSRP, while the Core i5-2550K debuted at $235. At current prices ($40 vs $46), the Core i5-6400T is $6 cheaper. In terms of value (PassMark points per dollar), the Core i5-6400T delivers 106.1 pts/$ vs 91.9 pts/$ for the Core i5-2550K — making the Core i5-6400T the 14.3% better value option.