CPU Comparison
Intel Core i5-8400 vs Intel Core i3-8100
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.
The lack of Hyper-Threading severely limits performance in heavily threaded office applications compared to newer 8-thread budget chips.
Gaming
Capable of smooth 1080p gaming when paired with a mid-range discrete GPU.
Paired with a strong discrete GPU, it can still handle older eSports titles, but modern AAA games will be heavily CPU bottlenecked.
Virtualization
Good for basic VMs, but 6 threads limit heavy parallel virtualization.
4 threads is the absolute minimum for running a modern OS and a single light virtual machine.
Efficiency
Balanced performance within a standard 65W power envelope.
The 14nm process is power-hungry compared to modern 7nm or 5nm alternatives, drawing 65W for modest performance.
Specialized Performance
AI / ML
- No AI-specific hardware
- CPU inference is slow due to lack of threads
- No AI hardware acceleration
- Lacks AVX-512
- Far too slow for any practical AI inference
Content Creation
Gaming
- Excellent for budget gaming builds
- Handles eSports titles flawlessly
- May bottleneck high-end modern GPUs at 1080p
- Requires a dedicated GPU for any gaming
- Fixed clock speed prevents single-thread boosts
- 4 cores are becoming the bare minimum for modern games
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
- Historically significant for bringing 4 cores to the i3 tier
- Very cheap on the used market
- Low 65W TDP is easy to cool
- UHD 630 iGPU is sufficient for basic display tasks
- Stable, mature platform with abundant used motherboards
Cons
- No Hyper-Threading (4 cores, 4 threads only)
- No Turbo Boost (fixed 3.6 GHz clock)
- DDR4 memory speed artificially capped at 2400 MT/s
- Outdated 14nm architecture with poor efficiency
- Limited to PCIe 3.0
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 i3-8100
- AMD Ryzen 3 1200Rival
Budget Desktop
- AMD Ryzen 3 2200GRival
Budget Desktop APU
- Intel Pentium Gold G5400Rival
Entry Desktop
- AMD Ryzen 5 1400Rival
Mid-Range Desktop
- Compare head-to-headIntel Core i5-7400Rival
Previous Gen Mid-Range
A drop-in replacement (with a BIOS update) that adds Hyper-Threading for 8 threads and much higher clocks.
Compare head-to-head- AMD Ryzen 3 3100Alt
Offers SMT (8 threads) and a modern upgrade path to Ryzen 5000 series.
If staying on the exact same platform, the 8400 offers 6 cores for much better multitasking.
Compare head-to-head- AMD Ryzen 5 3600Alt
A massively faster 12-thread CPU that redefines budget performance.
The current king of budget computing, offering IPC gains that make the 8100 look stationary.
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 landmark chip in 2017 for bringing quad-core computing to the masses, but thoroughly outclassed by modern budget processors in every metric.
Best for: The only justifiable scenario for purchasing an Intel Core i3-8100 today is if you are repairing an existing LGA 1151 v2 system (like an office PC or a hand-me-down) and can find the CPU for under $20 on the used market. Even then, you must consider that the 8100 lacks Hyper-Threading, which severely limits its longevity in modern operating systems that are increasingly optimized for 8 or more threads. If you are building a new system, even the absolute cheapest new motherboard and CPU combo from AMD or Intel's 12th/13th gen will offer exponentially better performance, efficiency, and platform features like PCIe 4.0 or DDR5. Do not buy this CPU for gaming, as the lack of Turbo Boost and Hyper-Threading will cause severe stuttering in modern titles compared to a modern Ryzen 3.
Read the full reviewFrequently Asked Questions
Which is better, Intel Core i5-8400 or Intel Core i3-8100?
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 i3-8100?
For gaming, the Intel Core i5-8400 leads with a gaming performance score of 78/100 among Intel Core i5-8400 and Intel Core i3-8100.
Do Intel Core i5-8400 and Intel Core i3-8100 use the same socket?
No. They use different sockets (Intel Core i5-8400: Intel Socket 1151, Intel Core i3-8100: LGA 1151), 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 i3-8100 (4 cores).