Core i5-8259U vs Core i5-9400H

PassMark CPU Mark evaluates processor speed through complex mathematical computations. It provides a reliable metric to compare multi-core performance, where higher scores indicate faster processing for multitasking, gaming, and heavy workloads.

Core i5-8259U vs Core i5-9400H FPS Benchmarks

Predicted gaming performance across popular games. Tested paired with GeForce RTX 5090 to isolate CPU performance.

Search any supported game below to compare 1080p FPS for both components.

Core i5-8259U vs Core i5-9400H: Pros, Cons & Final Verdict

See where each CPU makes more sense in practice: gaming, heavier work, platform cost, power draw, and upgrade path.

Core i5-8259U

2018

Why buy it

✅+0.6% higher PassMark.
✅Draws 28W instead of 45W, a 17W reduction.

Trade-offs

❌Smaller total L3 cache (6 MB vs 8 MB).
❌No integrated graphics, while Core i5-9400H can still boot and troubleshoot without a discrete GPU.

Core i5-9400H

2019

Why buy it

✅+33.3% larger total L3 cache (8 MB vs 6 MB).
✅100+% more PCIe lanes (16 vs 0) for storage and expansion-heavy builds.
✅Integrated graphics onboard with UHD Graphics 630, while Core i5-8259U needs a discrete GPU.

Trade-offs

❌Lower PassMark (7,794 vs 7,843).
❌Launch MSRP is still $182 MSRP, while Core i5-8259U mostly shows up through inconsistent older-market listings.
❌60.7% higher power demand at 45W vs 28W.

Quick Answers

So, is Core i5-9400H better than Core i5-8259U?

It depends on what you want from the system. For gaming, Core i5-9400H is ahead with a 1.4% average FPS lead across 50 shared CPU game tests in our data. For rendering, compiling, streaming, and heavier multitasking, Core i5-8259U pulls ahead with 0.6% better PassMark. Core i5-9400H also has the bigger cache pool with 33.3% larger total L3 cache (8 MB vs 6 MB).

Which one is better for streaming, content creation, and heavy multitasking?

For streaming, content creation, and heavier multitasking, Core i5-8259U is the stronger fit. You are getting 0.6% better PassMark, backed by 4 cores and 8 threads.

Which one is the smarter buy today, not just the cheaper CPU?

Core i5-9400H is the better buy right now. Core i5-9400H comes in at an unclear MSRP at $182 MSRP versus unclear MSRP, and it still gives you a 1.4% average FPS lead across 50 shared CPU game tests in our data. The compromise is that Core i5-8259U is still stronger for heavier multi-core work with 0.6% better PassMark. It is also 100.0% better value on MSRP (42.8 vs 0.0 PassMark/$), so you are getting the faster CPU without taking a value hit on paper.

Which one is more future-proof for 2026 and beyond?

Core i5-9400H makes more sense long term for 2026 and beyond. You are getting a newer CPU generation (2019 vs 2018) and 33.3% larger total L3 cache (8 MB vs 6 MB). That makes it the safer long-term bet.

Core i5-8259U vs Core i5-9400H Technical Specifications

Side-by-side specs, architecture details, clocks, memory, power, and platform differences.

Core i5-8259U

The Core i5-8259U is manufactured by Intel. It was released in 5 April 2018 (7 years ago). It is based on the Coffee Lake-U (2018−2019) architecture. It features 4 cores and 8 threads. Base frequency is 2.3 GHz, with boost up to 3.8 GHz. L3 cache: 6 MB (total). L2 cache: 256K (per core). Built on 14 nm process technology. Socket: FCBGA1528. Thermal design power (TDP): 28 Watt. Memory support: DDR4. Passmark benchmark score: 7,843 points. Launch price was $320.

Core i5-9400H

The Core i5-9400H is manufactured by Intel. It was released in 23 April 2019 (6 years ago). It is based on the Coffee Lake-H (2018−2019) architecture. It features 4 cores and 8 threads. Base frequency is 2.5 GHz, with boost up to 4.3 GHz. L3 cache: 8 MB. L2 cache: 1 MB. Built on 14 nm process technology. Socket: BGA1440. Thermal design power (TDP): 45 Watt. Memory support: DDR4. Passmark benchmark score: 7,794 points. Launch price was $149.

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Processing Power

Both the Core i5-8259U and Core i5-9400H share an identical 4-core/8-thread configuration. Boost clocks reach 3.8 GHz on the Core i5-8259U versus 4.3 GHz on the Core i5-9400H — a 12.3% clock advantage for the Core i5-9400H (base: 2.3 GHz vs 2.5 GHz). The Core i5-8259U uses the Coffee Lake-U (2018−2019) architecture (14 nm), while the Core i5-9400H uses Coffee Lake-H (2018−2019) (14 nm). In PassMark, the Core i5-8259U scores 7,843 against the Core i5-9400H's 7,794 — a 0.6% lead for the Core i5-8259U. L3 cache: 6 MB (total) on the Core i5-8259U vs 8 MB on the Core i5-9400H.

Feature	Core i5-8259U	Core i5-9400H
Cores / Threads	4 / 8	4 / 8
Boost Clock	3.8 GHz	4.3 GHz+13%
Base Clock	2.3 GHz	2.5 GHz+9%
L3 Cache	6 MB (total)	8 MB+33%
L2 Cache	256K (per core)+25500%	1 MB
Process	14 nm	14 nm
Architecture	Coffee Lake-U (2018−2019)	Coffee Lake-H (2018−2019)
PassMark	7,843	7,794
Geekbench 6 Single	—	1,341

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Memory & Platform

The Core i5-8259U uses the FCBGA1528 socket (PCIe 3.0), while the Core i5-9400H uses BGA1440 (PCIe 3.0) — making them incompatible on the same motherboard.

Feature	Core i5-8259U	Core i5-9400H
Socket	FCBGA1528	BGA1440
PCIe Generation	PCIe 3.0	PCIe 3.0
Max RAM Speed	—	DDR4-2666
Max RAM Capacity	—	128 GB
RAM Channels	—	2
ECC Support	—	No
PCIe Lanes	—	16

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Advanced Features

Virtualization: not specified (Core i5-8259U) / VT-x, VT-d, EPT (Core i5-9400H). The Core i5-9400H includes integrated graphics (UHD Graphics 630), while the Core i5-8259U requires a dedicated GPU. Primary use case: Core i5-9400H targets High Performance Laptop. Direct competitor: Core i5-9400H rivals Ryzen 5 4600H.