Core i5-8400T 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 i5-8400T 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 i5-8400T 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 i5-8400T

2018

Why buy it

✅+0.4% higher PassMark.
✅Costs $196 less on MSRP ($182 MSRP vs $378 MSRP).
✅Delivers 108.5% more PassMark for each dollar spent, at 40.8 vs 19.6 PassMark/$ ($182 MSRP vs $378 MSRP).
✅Draws 35W instead of 45W, a 10W reduction.
✅100+% more PCIe lanes (16 vs 0) for storage and expansion-heavy builds.

Trade-offs

❌Worse for gaming: lower average FPS than Core i7-7820HK across 50 shared CPU benchmark tests.

Core i7-7820HK

2017

Why buy it

✅Better for gaming: +14.4% higher average FPS across 50 shared CPU benchmark tests.

Trade-offs

❌Lower PassMark (7,397 vs 7,426).
❌Lower PassMark per dollar, at 19.6 vs 40.8 PassMark/$ ($378 MSRP vs $182 MSRP).
❌28.6% higher power demand at 45W vs 35W.
❌No integrated graphics, while Core i5-8400T can still boot and troubleshoot without a discrete GPU.
❌No boxed cooler included, unlike Core i5-8400T.

Quick Answers

So, is Core i5-8400T better than Core i7-7820HK?

It depends on what you want from the system. For gaming, Core i7-7820HK is ahead with a 14.4% average FPS lead across 50 shared CPU game tests in our data. For rendering, compiling, streaming, and heavier multitasking, Core i5-8400T pulls ahead with 0.4% better PassMark.

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

For streaming, content creation, and heavier multitasking, Core i5-8400T is the stronger fit. You are getting 0.4% better PassMark, backed by 6 cores and 6 threads.

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

Core i5-8400T is the better buy right now. Core i5-8400T comes in $196 cheaper on MSRP at $182 MSRP versus $378 MSRP, and it still gives you 0.4% better PassMark. The compromise is that Core i7-7820HK is still the better pure gaming CPU with a 14.4% average FPS lead across 50 shared CPU game tests in our data. It is also 108.5% better value on MSRP (40.8 vs 19.6 PassMark/$), 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 i5-8400T makes more sense long term for 2026 and beyond. You are getting a newer CPU generation (2018 vs 2017) and more multi-core headroom with 6 cores / 6 threads instead of 4/8. That extra compute headroom is more likely to matter as games, background tasks, and creator workloads get heavier.

Core i5-8400T vs Core i7-7820HK Technical Specifications

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

Core i5-8400T

The Core i5-8400T is manufactured by Intel. It was released in 2 April 2018 (7 years ago). It is based on the Coffee Lake (2017−2019) architecture. It features 6 cores and 6 threads. Base frequency is 1.7 GHz, with boost up to 3.3 GHz. L3 cache: 9 MB (total). L2 cache: 256K (per core). Built on 14 nm process technology. Socket: LGA1151. Thermal design power (TDP): 35 Watt. Memory support: DDR4-2666. Passmark benchmark score: 7,426 points. Launch price was $182.

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

The Core i5-8400T packs 6 cores / 6 threads, while the Core i7-7820HK 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 3.9 GHz on the Core i7-7820HK — a 16.7% clock advantage for the Core i7-7820HK (base: 1.7 GHz vs 2.9 GHz). The Core i5-8400T uses the Coffee Lake (2017−2019) architecture (14 nm), while the Core i7-7820HK uses Kaby Lake-H (2017) (14 nm). In PassMark, the Core i5-8400T scores 7,426 against the Core i7-7820HK's 7,397 — a 0.4% lead for the Core i5-8400T. L3 cache: 9 MB (total) on the Core i5-8400T vs 8 MB (total) on the Core i7-7820HK.

Feature	Core i5-8400T	Core i7-7820HK
Cores / Threads	6 / 6+50%	4 / 8
Boost Clock	3.3 GHz	3.9 GHz+18%
Base Clock	1.7 GHz	2.9 GHz+71%
L3 Cache	9 MB (total)+13%	8 MB (total)
L2 Cache	256K (per core)	256K (per core)
Process	14 nm	14 nm
Architecture	Coffee Lake (2017−2019)	Kaby Lake-H (2017)
PassMark	7,426	7,397
Cinebench R23 Multi	3,737	—
Geekbench 6 Single	1,092	—
Geekbench 6 Multi	3,816	—

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Memory & Platform

The Core i5-8400T uses the LGA1151 socket (PCIe 3.0), while the Core i7-7820HK uses BGA1440 (PCIe 3.0) — making them incompatible on the same motherboard.

Feature	Core i5-8400T	Core i7-7820HK
Socket	LGA1151	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: Yes (Core i5-8400T) / not specified (Core i7-7820HK). The Core i5-8400T includes integrated graphics (UHD Graphics 630), while the Core i7-7820HK requires a dedicated GPU.

Feature	Core i5-8400T	Core i7-7820HK
Integrated GPU	Yes	—
IGPU Model	UHD Graphics 630	—
AVX-512	No	—
Virtualization	Yes	—

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Value Analysis

At launch, the Core i5-8400T was priced at $182, while the Core i7-7820HK came in at $378. On launch pricing ($182 vs $378), Core i5-8400T was $196 cheaper. In terms of value on MSRP (PassMark points per dollar), the Core i5-8400T delivers 40.8 pts/$ vs 19.6 pts/$ for the Core i7-7820HK — making the Core i5-8400T the 70.3% better value option.

Feature	Core i5-8400T	Core i7-7820HK
MSRP	$182-52%	$378
Performance per Dollar	40.8+108%	19.6
Release Date	2018	2017

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