CPU Comparison
Intel Core i5-8400 vs Intel Core i5-7640X X-series
A side-by-side comparison of specs, performance and value. The Intel Core i5-8400 is a landmark mainstream desktop processor that fundamentally shifted the budget CPU market by bringing six physical cores to the i5 tier for the first time.
The Bottom Line
Overview & Launch
Specifications Compared
Performance Compared
Productivity
Handles office tasks and moderate programming workloads efficiently.
Four cores with no Hyper-Threading limit multi-threaded workloads; better suited to light productivity than heavy rendering or compiling.
Gaming
Capable of smooth 1080p gaming when paired with a mid-range discrete GPU.
Sufficient for high-refresh gaming when paired with a strong GPU, but constrained by lack of Hyper-Threading and limited core count in modern titles.
Virtualization
Good for basic VMs, but 6 threads limit heavy parallel virtualization.
Can run modest VM loads, but core and thread count make it less ideal for multiple concurrent VMs.
Efficiency
Balanced performance within a standard 65W power envelope.
High 112 W TDP for a quad-core design results in lower performance-per-watt than newer mainstream platforms.
Specialized Performance
AI / ML
- No AI-specific hardware
- CPU inference is slow due to lack of threads
- No dedicated AI acceleration; CPU-bound inference only.
- Lacks AVX-512; limited to SSE4.1/4.2 and AVX2 instruction sets.
Content Creation
Gaming
- Excellent for budget gaming builds
- Handles eSports titles flawlessly
- May bottleneck high-end modern GPUs at 1080p
- High clocks help in CPU-bound scenarios, but modern games increasingly benefit from more cores/threads.
- Requires a discrete GPU; no integrated graphics.
- Performance comparable to contemporary mainstream Kaby Lake i5s when GPU-bound.
Industry Impact
Best CPU by Use Case
Target Audience
Strengths & Weaknesses
Pros
- Disruptive price-to-performance ratio
- 6 physical cores for modern gaming
- Includes integrated UHD Graphics 630
- Standard 65W TDP is easy to cool
- Wide compatibility with 300-series motherboards
Cons
- No Hyper-Threading (only 6 threads)
- Locked multiplier prevents overclocking
- End-of-life platform (LGA 1151)
- Officially limited to DDR4-2666
- Not supported by Windows 11 officially
Pros
- High base and boost clock speeds
- Unlocked multiplier for overclocking
- Supports Intel Optane Memory
- VT-x and VT-d virtualization support
- DDR4-2666 dual-channel memory support
Cons
- No integrated graphics requires a discrete GPU
- No Hyper-Threading; only four threads
- Only dual-channel memory on a HEDT platform
- Only 16 CPU PCIe 3.0 lanes
- Discontinued platform with limited upgrade options
Competitors & Alternatives
Intel Core i5-8400
- AMD Ryzen 5 1600Rival
Mainstream Desktop
- Compare head-to-headIntel Core i5-7500Rival
Mainstream Desktop
- AMD Ryzen 5 2600Rival
Mainstream Desktop
- Intel Core i7-7700Rival
Mainstream Desktop
- AMD Ryzen 5 2400GRival
Mainstream Desktop
Slightly newer generation with marginally higher clocks.
Compare head-to-headNewer platform with 8 threads and similar gaming performance.
Compare head-to-headLow power alternative for SFF builds.
Compare head-to-head
Intel Core i5-7640X X-series
- AMD Ryzen 5 1600Rival
Mainstream
- AMD Ryzen 5 1500XRival
Mainstream
- Compare head-to-headIntel Core i5-7600KRival
Mainstream
- Intel Core i7-7700KRival
Mainstream
- RivalCompare head-to-head
Six-core mainstream Coffee Lake with better multi-threaded performance.
Compare head-to-head- AMD Ryzen 5 2600Alt
Six cores, 12 threads on AM4 with superior efficiency and upgrade path.
Later-generation six-core with higher clocks and improved platform longevity.
Compare head-to-head- AMD Ryzen 5 3600Alt
Zen 2 six-core with much higher IPC and efficiency on AM4.
Six-core, 12-thread Comet Lake on modern platform with DDR4 and better connectivity.
Compare head-to-head
Our Verdict on Each
A legendary value CPU that forced the market to adopt 6 cores as the standard. Excellent for budget gaming, though lacking Hyper-Threading.
Best for: Upgrading an older LGA 1151 system on a budget, or building an office/HTPC machine.
Read the full reviewA capable but ill-positioned quad-core for the X299 HEDT platform, offering strong clock speeds yet lacking Hyper-Threading, integrated graphics, and the multi-threaded punch of contemporaries; mainly relevant today for specific upgrades or used-market builds.
Best for: Upgrading an existing X299 system on a tight budget or acquiring used parts at low cost
Read the full reviewFrequently Asked Questions
Which is better, Intel Core i5-8400 or Intel Core i5-7640X X-series?
Based on our editorial ratings, the Intel Core i5-8400 comes out ahead with a score of 8.5/10. That said, the best choice depends on your workload — check the spec and performance breakdown above for gaming, productivity and efficiency differences.
Which is faster for gaming, Intel Core i5-8400 or Intel Core i5-7640X X-series?
For gaming, the Intel Core i5-8400 leads with a gaming performance score of 78/100 among Intel Core i5-8400 and Intel Core i5-7640X X-series.
Which uses less power?
The Intel Core i5-8400 has the lowest rated TDP. Power draw across these chips: Intel Core i5-8400 (65 W), Intel Core i5-7640X X-series (112 W).
Do Intel Core i5-8400 and Intel Core i5-7640X X-series use the same socket?
No. They use different sockets (Intel Core i5-8400: Intel Socket 1151, Intel Core i5-7640X X-series: FCLGA2066), so each needs a compatible motherboard.
Which has more cores?
The Intel Core i5-8400 has the most cores. Core counts: Intel Core i5-8400 (6 cores), Intel Core i5-7640X X-series (4 cores).