Core i5-8400T vs Core i5-8400H

The Core i5-8400T packs 6 cores / 6 threads, while the Core i5-8400H offers 4 cores / 8 threads — the Core i5-8400T has 2 more cores. Boost clocks reach 3.3 GHz on the Core i5-8400T versus 4.2 GHz on the Core i5-8400H — a 24% clock advantage for the Core i5-8400H (base: 1.7 GHz vs 2.5 GHz). The Core i5-8400T uses the Coffee Lake (2017−2019) architecture (14 nm), while the Core i5-8400H uses Coffee Lake-H (2018−2019) (14 nm). In PassMark, the Core i5-8400T scores 7,426 against the Core i5-8400H's 7,456 — a 0.4% lead for the Core i5-8400H. Cinebench R23 multi-core: 3,737 vs 4,657 (21.9% advantage for the Core i5-8400H). Geekbench 6 single-core — the metric most relevant to gaming — records 1,092 vs 1,493, a 31% lead for the Core i5-8400H that directly translates to higher frame rates. Multi-core Geekbench: 3,816 vs 4,963 (26.1% advantage for the Core i5-8400H). L3 cache: 9 MB (total) on the Core i5-8400T vs 12 MB (total) on the Core i5-8400H.

The Core i5-8400T uses the LGA1151 socket (PCIe 3.0), while the Core i5-8400H uses BGA1440 (PCIe 3.0) — making them incompatible on the same motherboard. Maximum memory speed reaches DDR4-2666 on the Core i5-8400T versus DDR4 2666 MHz on the Core i5-8400H — the Core i5-8400H supports 200% faster memory, which can translate to measurable gains in memory-sensitive workloads. The Core i5-8400T supports up to 128 GB of RAM compared to 64 GB — 66.7% more capacity for professional workloads. Both feature 2-channel memory with ECC support. Both provide 16 PCIe lanes. Chipset compatibility: H310,B360,H370,Q370,Z370,Z390 (Core i5-8400T) and Intel HM370,Intel QM370 (Core i5-8400H).

Virtualization support: Yes (Core i5-8400T) vs true (Core i5-8400H). Both include integrated graphics — UHD Graphics 630 (Core i5-8400T) and Intel UHD Graphics 630 (Core i5-8400H) — useful as a fallback for troubleshooting or display output without a dedicated GPU. Primary use case: Core i5-8400H targets Mobile.