Core i5-8257U vs Core i7-7820HK

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 i5-8257U vs Core i7-7820HK 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 i5-8257U vs Core i7-7820HK: Pros, Cons & Final Verdict

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

Core i5-8257U

2019

Why buy it

✅+0.4% higher PassMark.
✅Draws 1W instead of 45W, a 44W reduction.
✅100+% more PCIe lanes (16 vs 0) for storage and expansion-heavy builds.
✅Integrated graphics onboard with Intel Iris Plus Graphics 645, while Core i7-7820HK needs a discrete GPU.

Trade-offs

❌Worse for gaming: lower average FPS than Core i7-7820HK across 50 shared CPU benchmark tests.
❌Smaller total L3 cache (6 MB vs 8 MB).

Core i7-7820HK

2017

Why buy it

✅Better for gaming: +6.6% higher average FPS across 50 shared CPU benchmark tests.
✅+33.3% larger total L3 cache (8 MB vs 6 MB).

Trade-offs

❌Lower PassMark (7,397 vs 7,427).
❌Launch MSRP is still $378 MSRP, while Core i5-8257U mostly shows up through inconsistent older-market listings.
❌4400% higher power demand at 45W vs 1W.
❌No integrated graphics, while Core i5-8257U can still boot and troubleshoot without a discrete GPU.

Quick Answers

So, is Core i5-8257U better than Core i7-7820HK?

It depends on what you want from the system. For gaming, Core i7-7820HK is ahead with a 6.6% average FPS lead across 50 shared CPU game tests in our data. For rendering, compiling, streaming, and heavier multitasking, Core i5-8257U pulls ahead with 0.4% better PassMark. Core i7-7820HK 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 i5-8257U is the stronger fit. You are getting 0.4% better PassMark, backed by 4 cores and 8 threads.

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

Core i5-8257U is the easy recommendation for a fresh desktop build. Core i5-8257U comes in at an unclear MSRP at unclear MSRP versus $378 MSRP, and it still gives you 0.4% better PassMark. Core i7-7820HK only looks good on raw value math because it is a cheap legacy laptop chip, not because it is a real desktop gaming recommendation. It simply does not keep up in modern games.

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

Core i5-8257U makes more sense long term for 2026 and beyond. You are getting a newer CPU generation (2019 vs 2017) and more multi-core headroom with 4 cores / 8 threads instead of 4/8. That extra compute headroom is more likely to matter as games, background tasks, and creator workloads get heavier.

Core i5-8257U vs Core i7-7820HK Technical Specifications

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

Core i5-8257U

The Core i5-8257U is manufactured by Intel. It was released in 10 July 2019 (6 years ago). It is based on the Coffee Lake-U (2018−2019) architecture. It features 4 cores and 8 threads. Base frequency is 1.4 GHz, with boost up to 3.9 GHz. L3 cache: 6 MB. L2 cache: 1 MB. Built on 14 nm process technology. Socket: FCBGA1528. Thermal design power (TDP): 15 Watt. Memory support: DDR4. Passmark benchmark score: 7,427 points. Launch price was $149.

Core i7-7820HK

The Core i7-7820HK is manufactured by Intel. It was released in 3 January 2017 (8 years ago). It is based on the Kaby Lake-H (2017) architecture. It features 4 cores and 8 threads. Base frequency is 2.9 GHz, with boost up to 3.9 GHz. L3 cache: 8 MB (total). L2 cache: 256K (per core). Built on 14 nm process technology. Socket: BGA1440. Thermal design power (TDP): 45 Watt. Memory support: DDR4. Passmark benchmark score: 7,397 points. Launch price was $378.

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Processing Power

Both the Core i5-8257U and Core i7-7820HK share an identical 4-core/8-thread configuration. Boost clocks reach 3.9 GHz on the Core i5-8257U versus 3.9 GHz on the Core i7-7820HK — identical boost frequencies (base: 1.4 GHz vs 2.9 GHz). The Core i5-8257U uses the Coffee Lake-U (2018−2019) architecture (14 nm), while the Core i7-7820HK uses Kaby Lake-H (2017) (14 nm). In PassMark, the Core i5-8257U scores 7,427 against the Core i7-7820HK's 7,397 — a 0.4% lead for the Core i5-8257U. L3 cache: 6 MB on the Core i5-8257U vs 8 MB (total) on the Core i7-7820HK.

Feature	Core i5-8257U	Core i7-7820HK
Cores / Threads	4 / 8	4 / 8
Boost Clock	3.9 GHz	3.9 GHz
Base Clock	1.4 GHz	2.9 GHz+107%
L3 Cache	6 MB	8 MB (total)+33%
L2 Cache	1 MB	256K (per core)+25500%
Process	14 nm	14 nm
Architecture	Coffee Lake-U (2018−2019)	Kaby Lake-H (2017)
PassMark	7,427	7,397
Cinebench R23 Multi	4,017	—
Geekbench 6 Single	1,100	—
Geekbench 6 Multi	4,000	—

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Memory & Platform

The Core i5-8257U uses the FCBGA1528 socket (PCIe 3.0), while the Core i7-7820HK uses BGA1440 (PCIe 3.0) — making them incompatible on the same motherboard.

Feature	Core i5-8257U	Core i7-7820HK
Socket	FCBGA1528	BGA1440
PCIe Generation	PCIe 3.0	PCIe 3.0
Max RAM Speed	DDR4-2400	—
Max RAM Capacity	32 GB	—
RAM Channels	2	—
ECC Support	No	—
PCIe Lanes	16	—

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Advanced Features

Virtualization: VT-x, VT-d (Core i5-8257U) / not specified (Core i7-7820HK). The Core i5-8257U includes integrated graphics (Intel Iris Plus Graphics 645), while the Core i7-7820HK requires a dedicated GPU. Primary use case: Core i5-8257U targets Ultrabook.