Core i5-8400 vs Core i7-9700K

CPU

GPU

Core i5-8400

6 Cores6 Thrd65 WWMax: 4 GHz2017

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Core i7-9700K

8 Cores8 Thrd95 WWMax: 4.9 GHz2018

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Core i5-8400 vs Core i7-9700K Performance Spectrum

Core i5-8400

6 / 6

9,229

0.0%

14,397

+56.0%

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.

Core i5-8400 vs Core i7-9700K 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 i5-8400 vs Core i7-9700K: Pros, Cons & Final Verdict

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

Core i5-8400

2017

Why buy it

✅Costs $203 less on MSRP ($182 MSRP vs $385 MSRP).
✅Delivers 35.6% more PassMark for each dollar spent, at 50.7 vs 37.4 PassMark/$ ($182 MSRP vs $385 MSRP).
✅Draws 65W instead of 95W, a 30W reduction.

Trade-offs

❌Worse for gaming: lower average FPS than Core i7-9700K across 50 shared CPU benchmark tests.
❌Lower PassMark (9,229 vs 14,397).
❌Smaller total L3 cache (9 MB vs 12 MB).

Core i7-9700K

2018

Why buy it

✅Better for gaming: +80.1% higher average FPS across 50 shared CPU benchmark tests.
✅+33.3% larger total L3 cache (12 MB vs 9 MB).

Trade-offs

❌Lower PassMark per dollar, at 37.4 vs 50.7 PassMark/$ ($385 MSRP vs $182 MSRP).
❌46.2% higher power demand at 95W vs 65W.

Quick Answers

So, is Core i7-9700K better than Core i5-8400?

Yes. Core i7-9700K is the better all-around CPU here. It gives you a 80.1% average FPS lead across 50 shared CPU game tests in our data, 56% better 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 i7-9700K is the better pick. According to our tests, it delivers 80.1% 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 i7-9700K is the stronger fit. You are getting 56% better PassMark, backed by 8 cores and 8 threads. It also has the larger cache pool with 33.3% larger total L3 cache (12 MB vs 9 MB).

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

Core i7-9700K is still the much better call for a fresh build. Core i7-9700K comes in 111.5% more expensive on MSRP at $385 MSRP versus $182 MSRP, and it still gives you a 80.1% average FPS lead across 50 shared CPU game tests in our data. Core i5-8400 only looks stronger on raw value math because it is extremely cheap, but that usually means used-market pricing on an obsolete 2017 platform. Even with 35.6% better value on paper (50.7 vs 37.4 PassMark/$), it really only makes sense as a cheap stopgap or a niche existing-platform option for someone already on LGA1151.

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

Core i7-9700K makes more sense long term for 2026 and beyond. You are getting a newer CPU generation (2018 vs 2017), 33.3% larger total L3 cache (12 MB vs 9 MB), and more multi-core headroom with 8 cores / 8 threads instead of 6/6. That extra compute headroom is more likely to matter as games, background tasks, and creator workloads get heavier.

Core i5-8400 vs Core i7-9700K Technical Specifications

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

Core i5-8400

The Core i5-8400 is manufactured by Intel. It was released in 5 October 2017 (8 years ago). It is based on the Coffee Lake-S (2017−2018) architecture. It features 6 cores and 6 threads. Base frequency is 2.8 GHz, with boost up to 4 GHz. L3 cache: 9 MB (total). L2 cache: 256K (per core). Built on 14 nm process technology. Socket: LGA1151. Thermal design power (TDP): 65 Watt. Memory support: DDR3, DDR4. Passmark benchmark score: 9,229 points. Launch price was $182.

Core i7-9700K

The Core i7-9700K is manufactured by Intel. It was released in 19 October 2018 (7 years ago). It is based on the Coffee Lake-R (2018−2019) architecture. It features 8 cores and 8 threads. Base frequency is 3.6 GHz, with boost up to 4.9 GHz. L3 cache: 12 MB (total). L2 cache: 256K (per core). Built on 14 nm process technology. Socket: LGA1151. Thermal design power (TDP): 95 Watt. Memory support: DDR4. Passmark benchmark score: 14,397 points. Launch price was $374.

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Processing Power

The Core i5-8400 packs 6 cores / 6 threads, while the Core i7-9700K offers 8 cores / 8 threads — the Core i7-9700K has 2 more cores. Boost clocks reach 4 GHz on the Core i5-8400 versus 4.9 GHz on the Core i7-9700K — a 20.2% clock advantage for the Core i7-9700K (base: 2.8 GHz vs 3.6 GHz). The Core i5-8400 uses the Coffee Lake-S (2017−2018) architecture (14 nm), while the Core i7-9700K uses Coffee Lake-R (2018−2019) (14 nm). In PassMark, the Core i5-8400 scores 9,229 against the Core i7-9700K's 14,397 — a 43.7% lead for the Core i7-9700K. L3 cache: 9 MB (total) on the Core i5-8400 vs 12 MB (total) on the Core i7-9700K.

Feature	Core i5-8400	Core i7-9700K
Cores / Threads	6 / 6	8 / 8+33%
Boost Clock	4 GHz	4.9 GHz+23%
Base Clock	2.8 GHz	3.6 GHz+29%
L3 Cache	9 MB (total)	12 MB (total)+33%
L2 Cache	256K (per core)	256K (per core)
Process	14 nm	14 nm
Architecture	Coffee Lake-S (2017−2018)	Coffee Lake-R (2018−2019)
PassMark	9,229	14,397+56%

🧠

Memory & Platform

Both processors use the LGA1151 socket with PCIe 3.0. Both support up to DDR4-2666 memory speed. Both support up to 128 GB of RAM. Both feature 2-channel memory with ECC support. Both provide 16 PCIe lanes. Chipset compatibility: Intel 300 series (Core i5-8400) and Intel 300 series (Core i7-9700K).

Feature	Core i5-8400	Core i7-9700K
Socket	LGA1151	LGA1151
PCIe Generation	PCIe 3.0	PCIe 3.0
Max RAM Speed	DDR4-2666	DDR4-2666
Max RAM Capacity	128 GB	128 GB
RAM Channels	2	2
ECC Support	No	No
PCIe Lanes	16	16

🔧

Advanced Features

Only the Core i7-9700K has an unlocked multiplier for overclocking — a significant advantage for enthusiasts seeking extra performance. Both support VT-x, VT-d virtualization. Both include integrated graphics — UHD Graphics 630 (Core i5-8400) and UHD Graphics 630 (Core i7-9700K) — useful as a fallback for troubleshooting or display output without a dedicated GPU. Primary use case: Core i5-8400 targets Desktop, Core i7-9700K targets Desktop.

Feature	Core i5-8400	Core i7-9700K
Integrated GPU	Yes	Yes
IGPU Model	UHD Graphics 630	UHD Graphics 630
Unlocked	No	Yes
AVX-512	No	No
Virtualization	VT-x, VT-d	VT-x, VT-d
Target Use	Desktop	Desktop

💰

Value Analysis

At launch, the Core i5-8400 was priced at $182, while the Core i7-9700K came in at $385. On launch pricing ($182 vs $385), Core i5-8400 was $203 cheaper. In terms of value on MSRP (PassMark points per dollar), the Core i5-8400 delivers 50.7 pts/$ vs 37.4 pts/$ for the Core i7-9700K — making the Core i5-8400 the 30.2% better value option.

Feature	Core i5-8400	Core i7-9700K
MSRP	$182-53%	$385
Performance per Dollar	50.7+36%	37.4
Release Date	2017	2018

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