Celeron 3865U vs Core i5-10400F

CPU

GPU

Celeron 3865U

2 Cores2 Thrd15 WWMax: 1.8 GHz2017

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Core i5-10400F

6 Cores12 Thrd65 WWMax: 4.3 GHz2020

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Celeron 3865U vs Core i5-10400F Performance Spectrum

Celeron 3865U

2 / 2

1,343

0.0%

13,029

+870.1%

About PassMark

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.

Celeron 3865U vs Core i5-10400F 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.

Celeron 3865U vs Core i5-10400F: Pros, Cons & Final Verdict

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

Celeron 3865U

2017

Why buy it

✅Draws 15W instead of 65W, a 50W reduction.
✅Integrated graphics onboard with Intel HD Graphics 610, while Core i5-10400F needs a discrete GPU.

Trade-offs

❌Worse for gaming: lower average FPS than Core i5-10400F across 50 shared CPU benchmark tests.
❌Lower Geekbench multi-core (674 vs 5,783).
❌Smaller total L3 cache (2 MB vs 12 MB).
❌No boxed cooler included, unlike Core i5-10400F.

Core i5-10400F

2020

Why buy it

✅Better for gaming: +430.6% higher average FPS across 50 shared CPU benchmark tests.
✅+500% larger total L3 cache (12 MB vs 2 MB).
✅60% more PCIe lanes (16 vs 10) for storage and expansion-heavy builds.
✅Includes a boxed cooler (Yes), unlike Celeron 3865U.

Trade-offs

❌Launch MSRP is still $160 MSRP, while Celeron 3865U mostly shows up through inconsistent older-market listings.
❌333.3% higher power demand at 65W vs 15W.
❌No integrated graphics, while Celeron 3865U can still boot and troubleshoot without a discrete GPU.

Quick Answers

So, is Core i5-10400F better than Celeron 3865U?

Yes. Core i5-10400F is the better all-around CPU here. It gives you a 430.6% average FPS lead across 50 shared CPU game tests in our data, 758% better Geekbench multi-core, 870.1% higher PassMark, and the stronger long-term platform, which is enough to make it the stronger overall pick.

Which one is better for gaming?

If gaming is the priority, Core i5-10400F is the better pick. According to our tests, it delivers 430.6% more average FPS across 50 shared CPU game tests.

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

For streaming, content creation, and heavier multitasking, Core i5-10400F is the stronger fit. You are getting 758% better Geekbench multi-core, backed by 6 cores and 12 threads. It also has the larger cache pool with 500% larger total L3 cache (12 MB vs 2 MB).

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

Core i5-10400F is the better buy right now. Core i5-10400F comes in at an unclear MSRP at $160 MSRP versus unclear MSRP, and it still gives you a 430.6% average FPS lead across 50 shared CPU game tests in our data. It is also 100.0% better value on MSRP (81.4 vs 0.0 PassMark/$), 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 i5-10400F makes more sense long term for 2026 and beyond. You are getting a newer CPU generation (2020 vs 2017), 500% larger total L3 cache (12 MB vs 2 MB), and more multi-core headroom with 6 cores / 12 threads instead of 2/2. That extra compute headroom is more likely to matter as games, background tasks, and creator workloads get heavier.

Celeron 3865U vs Core i5-10400F Technical Specifications

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

Celeron 3865U

The Celeron 3865U is manufactured by Intel. It was released in 3 January 2017 (8 years ago). It is based on the Kaby Lake-U (2017) architecture. It features 2 cores and 2 threads. Base frequency is 1.8 GHz, with boost up to 1.8 GHz. L3 cache: 2 MB (total). L2 cache: 256K (per core). Built on 14 nm process technology. Socket: BGA1356. Thermal design power (TDP): 15 Watt. Memory support: DDR3, DDR4. Passmark benchmark score: 1,343 points. Launch price was $107.

Core i5-10400F

The Core i5-10400F is manufactured by Intel. It was released in 30 April 2020 (5 years ago). It is based on the Comet Lake (2020−2025) architecture. It features 6 cores and 12 threads. Base frequency is 2.9 GHz, with boost up to 4.3 GHz. L3 cache: 12 MB (total). L2 cache: 256K (per core). Built on 14 nm process technology. Socket: LGA1200. Thermal design power (TDP): 65 Watt. Memory support: DDR4. Passmark benchmark score: 13,029 points. Launch price was $155.

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Processing Power

The Celeron 3865U packs 2 cores / 2 threads, while the Core i5-10400F offers 6 cores / 12 threads — the Core i5-10400F has 4 more cores. Boost clocks reach 1.8 GHz on the Celeron 3865U versus 4.3 GHz on the Core i5-10400F — a 82% clock advantage for the Core i5-10400F (base: 1.8 GHz vs 2.9 GHz). The Celeron 3865U uses the Kaby Lake-U (2017) architecture (14 nm), while the Core i5-10400F uses Comet Lake (2020−2025) (14 nm). In PassMark, the Celeron 3865U scores 1,343 against the Core i5-10400F's 13,029 — a 162.6% lead for the Core i5-10400F. Geekbench 6 single-core — the metric most relevant to gaming — records 389 vs 1,454, a 115.6% lead for the Core i5-10400F that directly translates to higher frame rates. Multi-core Geekbench: 674 vs 5,783 (158.2% advantage for the Core i5-10400F). L3 cache: 2 MB (total) on the Celeron 3865U vs 12 MB (total) on the Core i5-10400F.

Feature	Celeron 3865U	Core i5-10400F
Cores / Threads	2 / 2	6 / 12+200%
Boost Clock	1.8 GHz	4.3 GHz+139%
Base Clock	1.8 GHz	2.9 GHz+61%
L3 Cache	2 MB (total)	12 MB (total)+500%
L2 Cache	256K (per core)	256K (per core)
Process	14 nm	14 nm
Architecture	Kaby Lake-U (2017)	Comet Lake (2020−2025)
PassMark	1,343	13,029+870%
Cinebench R23 Multi	—	8,191
Geekbench 6 Single	389	1,454+274%
Geekbench 6 Multi	674	5,783+758%

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Memory & Platform

The Celeron 3865U uses the BGA1356 socket (PCIe 3.0), while the Core i5-10400F uses LGA1200 (PCIe 3.0) — making them incompatible on the same motherboard. Maximum memory speed reaches DDR4-2133 / LPDDR3-1866 on the Celeron 3865U versus DDR4-2666 on the Core i5-10400F — the Core i5-10400F supports 25% faster memory, which can translate to measurable gains in memory-sensitive workloads. The Core i5-10400F supports up to 128 GB of RAM compared to 32 GB — 300% more capacity for professional workloads. Both feature 2-channel memory with ECC support. PCIe lanes: 10 (Celeron 3865U) vs 16 (Core i5-10400F) — the Core i5-10400F offers 6 more lanes for additional GPUs or NVMe drives. Chipset compatibility: 100-series,200-series (Celeron 3865U) and H410,B460,H470,Z490,H510,B560,H570,Z590 (Core i5-10400F).

Feature	Celeron 3865U	Core i5-10400F
Socket	BGA1356	LGA1200
PCIe Generation	PCIe 3.0	PCIe 3.0
Max RAM Speed	DDR4-2133 / LPDDR3-1866	DDR4-2666+25%
Max RAM Capacity	32 GB	128 GB+300%
RAM Channels	2	2
ECC Support	No	No
PCIe Lanes	10	16+60%

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Advanced Features

Neither processor supports overclocking. Virtualization support: VT-x / VT-d / EPT (Celeron 3865U) vs VT-x, VT-d (Core i5-10400F). The Celeron 3865U includes integrated graphics (Intel HD Graphics 610), while the Core i5-10400F requires a dedicated GPU. Primary use case: Celeron 3865U targets Entry-level, Core i5-10400F targets Gaming. Direct competitor: Celeron 3865U rivals Pentium Gold 4415U; Core i5-10400F rivals Ryzen 5 3600.