CPU Comparison
Core i5-7640X vs Intel Core i3-8350K
A side-by-side comparison of specs, performance and value. The Intel Core i5-7640X is a unique entry in Intel's 7th generation lineup, blurring the lines between mainstream and high-end desktop (HEDT) platforms. Released on June 26, 2017, it was part of the Kaby Lake-X family, designed for the LGA 2066 socket. Unlike traditional Core i5 processors of its era, the 7640X featured an unlocked multiplier, allowing enthusiasts to push the 3.9 GHz base clock well beyond its 4.3 GHz turbo limit. However, it also carried quirks: it only supported dual-channel memory despite being on a quad-channel platform, and lacked integrated graphics. Aimed at gamers and budget-conscious overclockers wanting access to the X299 chipset, its position in the market was somewhat controversial, as it offered fewer PCIe lanes than its larger siblings. Despite this, it provided excellent single-threaded performance for its time and remains an interesting footnote in Intel's HEDT strategy.
The Bottom Line
Overview & Launch
Specifications Compared
Performance Compared
Productivity
Adequate for basic office tasks and light workloads, but falls behind in heavily multi-threaded applications.
Overclocking does not add threads. For heavily threaded productivity work, a stock 6-core CPU will easily beat an overclocked 4-core i3.
Gaming
Performs well in older or less demanding games due to high IPC and clock speeds, but bottlenecks modern titles due to 4-core/4-thread limitations.
At stock speeds, it is comparable to other 8th-gen i3s. When overclocked to 5.0 GHz+, it can match stock i5s in eSports titles, but the lack of threads hurts in modern AAA games.
Virtualization
Limited utility for virtualization due to the lack of Hyper-Threading and low core count.
4 threads is a hard limit for virtualization, regardless of how fast those threads run.
Efficiency
14nm process and 112W TDP for a 4-core chip result in poor efficiency compared to mainstream alternatives.
Terrible efficiency. Pushing 1.3V+ through 14nm silicon to hit 5.0 GHz results in massive power draw and heat.
Specialized Performance
AI / ML
- No dedicated AI hardware
- Low core count limits CPU-based inference
- No AI acceleration
- High clock speed cannot compensate for lack of AI instructions
Content Creation
Gaming
- High clock speeds benefit high-refresh-rate gaming
- 4 cores struggle with modern CPU-intensive titles
- Requires a dedicated GPU
- Requires heavy overclocking to be relevant
- High clock speeds benefit older eSports titles
- 4 cores/4 threads is a severe limitation for modern AAA gaming
Industry Impact
Best CPU by Use Case
Target Audience
Strengths & Weaknesses
Pros
- Unlocked multiplier for overclocking
- High 4.3 GHz turbo frequency
- Access to X299 chipset features
- Strong single-core performance for its era
Cons
- Only 4 cores and 4 threads
- Limited to dual-channel memory
- Only 16 PCIe lanes
- Lacks integrated graphics
- Poor price-to-performance ratio at launch
Pros
- First unlocked i3, historic significance
- Massive overclocking headroom (5.0 GHz+ on air)
- 8MB L3 cache aids high-frequency stability
- Fun project chip for hardware enthusiasts
- High stock clock of 4.0 GHz
Cons
- No Hyper-Threading (4 cores, 4 threads only)
- Requires expensive Z-series motherboard
- Terrible power efficiency when overclocked
- Outperformed by cheaper locked 6-core CPUs
- Obsolete LGA 1151 v2 platform
Competitors & Alternatives
Core i5-7640X
- AMD Ryzen 5 1500XRival
Mainstream
- Compare head-to-headIntel Core i5-7600KRival
Mainstream
- AMD Ryzen 5 1600Rival
Mainstream
- RivalCompare head-to-head
- Compare head-to-headIntel Core i5-8400Rival
Mainstream
Offers more cores and better platform longevity on Z370.
Compare head-to-head- AMD Ryzen 5 2600Alt
Provides 6 cores and 12 threads for better multi-threaded value.
- AMD Ryzen 5 3600Alt
Significantly faster single and multi-threaded performance on AM4.
Intel Core i3-8350K
- AMD Ryzen 3 1300XRival
Budget Desktop
- AMD Ryzen 5 1600Rival
Mid-Range Desktop
- Compare head-to-headIntel Core i5-8400Rival
Mid-Range Desktop
- Intel Core i3-8350KRival
Budget Enthusiast
- AMD Ryzen 5 2600Rival
Mid-Range Desktop
- AMD Ryzen 5 3600Alt
Offers 12 threads and modern platform features, destroying the 8350K in productivity and gaming for less total cost.
If you want to overclock on LGA 1151 v2, this gives you 6 cores to play with.
Compare head-to-headA modern budget king that doesn't need an expensive motherboard to perform well.
Compare head-to-head- AMD Ryzen 3 3100Alt
Offers 8 threads and PCIe 4.0 on a budget platform, making the 8350K obsolete.
Our Verdict on Each
A peculiar HEDT chip with high clock speeds but limited PCIe lanes and no Hyper-Threading, making it a niche product for overclockers rather than a true workstation CPU.
Best for: Hobbyist overclocking on a used X299 motherboard
Read the full reviewA fun overclocking toy in 2017, but the lack of Hyper-Threading and a high 91W TDP make it a poor value compared to even cheap modern chips.
Best for: You should avoid buying the Intel Core i3-8350K unless you are a dedicated overclocking hobbyist looking for a cheap project chip to practice manual tuning, delidding, or extreme cooling on. If you fall into that niche, buying a used 8350K for $20 and pushing it to 5.0 GHz can be incredibly fun and educational. However, for any practical use case—gaming, work, or productivity—this chip is a poor investment. It requires an expensive Z370 or Z390 motherboard to utilize its only feature (overclocking), yet a locked Ryzen 5 3600 on a cheap B450 board will destroy it in every multi-threaded benchmark while using less power. The lack of Hyper-Threading is a fatal flaw that no amount of frequency can fix. Spend your money on modern hardware.
Read the full reviewFrequently Asked Questions
Which is better, Core i5-7640X or Intel Core i3-8350K?
Based on our editorial ratings, the Core i5-7640X comes out ahead with a score of 6.5/10. 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, Core i5-7640X or Intel Core i3-8350K?
For gaming, the Intel Core i3-8350K leads with a gaming performance score of 40/100 among Core i5-7640X and Intel Core i3-8350K.
Which uses less power?
The Intel Core i3-8350K has the lowest rated TDP. Power draw across these chips: Core i5-7640X (112 W), Intel Core i3-8350K (91 W).
Do Core i5-7640X and Intel Core i3-8350K use the same socket?
No. They use different sockets (Core i5-7640X: LGA 2066, Intel Core i3-8350K: LGA 1151), so each needs a compatible motherboard.