Core i5-9300H vs Core i5-8257U

Both the Core i5-9300H and Core i5-8257U share an identical 4-core/8-thread configuration. Boost clocks reach 4.1 GHz on the Core i5-9300H versus 3.9 GHz on the Core i5-8257U — a 5% clock advantage for the Core i5-9300H (base: 2.4 GHz vs 1.4 GHz). The Core i5-9300H uses the Coffee Lake-H (2018−2019) architecture (14 nm), while the Core i5-8257U uses Coffee Lake-U (2018−2019) (14 nm). In PassMark, the Core i5-9300H scores 7,438 against the Core i5-8257U's 7,427 — a 0.1% lead for the Core i5-9300H. Cinebench R23 multi-core: 4,729 vs 4,017 (16.3% advantage for the Core i5-9300H). Geekbench 6 single-core — the metric most relevant to gaming — records 1,050 vs 1,100, a 4.7% lead for the Core i5-8257U that directly translates to higher frame rates. Multi-core Geekbench: 3,700 vs 4,000 (7.8% advantage for the Core i5-8257U). L3 cache: 8 MB on the Core i5-9300H vs 6 MB on the Core i5-8257U.

The Core i5-9300H uses the BGA1440 socket (PCIe 3.0), while the Core i5-8257U uses FCBGA1528 (PCIe 3.0) — making them incompatible on the same motherboard. Both support up to DDR4-2666 memory speed. The Core i5-9300H supports up to 128 GB of RAM compared to 32 GB — 120% more capacity for professional workloads. Both feature 2-channel memory with ECC support. Both provide 16 PCIe lanes. Chipset compatibility: HM370 (Core i5-9300H) and 300 Series (Core i5-8257U).

Neither processor supports overclocking. Both support VT-x, VT-d virtualization. Both include integrated graphics — Intel UHD Graphics 630 (Core i5-9300H) and Intel Iris Plus Graphics 645 (Core i5-8257U) — useful as a fallback for troubleshooting or display output without a dedicated GPU. Primary use case: Core i5-9300H targets Gaming Laptop, Core i5-8257U targets Ultrabook.