CPU Comparison

Intel Core i5-7640X X-series vs Intel Core i7-7820X

A side-by-side comparison of specs, performance and value. The Intel Core i5-7640X is a quad-core, four-thread desktop processor on the LGA2066 platform with base and boost clocks of 4.0 GHz and 4.2 GHz, respectively, dual-channel DDR4-2666 memory, and 16 PCIe 3.0 lanes.

Intel · Core i5
Intel Core i5-7640X X-series
4C / 4T4.2 GHz112 W
6
Full review
Top pick
Intel · Core i7
Intel Core i7-7820X
8C / 16T4.5 GHz140 W
7.5
Full review

The Bottom Line

Overview & Launch

Brand
Intel
Intel
Market
High-End Desktop (HEDT)
High-End Desktop (HEDT)
Generation
7th Gen Core X-Series
7th Gen X-Series (Skylake-X)
Launched
2017
2017
Status
Discontinued
Discontinued
Codename
Kaby Lake-X
Skylake-X
Series
Core i5
Core i7
Family
X-Series 7th Gen (Core i5)
X-Series 7th Gen (Core i7)
Predecessor
Intel Core i7-6900K
Successor
Platform Discontinued (Kaby Lake-X line)
Platform discontinued; refreshed X299 and later Core X-series succeeded this lineup

Specifications Compared

Cores & Clocks
Cores
4
8
Threads
4
16
Base Clock
4 GHz
3.6 GHz
Boost Clock
4.2 GHz
4.5 GHz
Cache & Power
L3 Cache
6 MB
11 MB
TDP
112 W
140 W
Architecture
Architecture
Kaby Lake-X
Skylake-X
Process Node
14 nm
14 nm
Memory
Memory Type
DDR4
DDR4
Memory Speed
DDR4-2666
DDR4-2666
Memory Channels
Dual (2)
Quad (4)
Max Memory
64 GB
128 GB
Platform & I/O
Socket
FCLGA2066
LGA2066
PCIe Version
3.0
3.0
PCIe Lanes
16
28
Integrated GPU
None
None
Unlocked
Yes
Yes

Performance Compared

Productivity

Intel Core i5-7640X X-series58

Four cores with no Hyper-Threading limit multi-threaded workloads; better suited to light productivity than heavy rendering or compiling.

Intel Core i7-7820XBest88

Strong multi-threaded throughput in CINEBENCH, HandBrake, and similar workloads at launch; still competent for many content creation tasks compared to modern mainstream parts.

Gaming

Intel Core i5-7640X X-series72

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.

Intel Core i7-7820XBest78

Delivers high frame rates in 2017-era titles and remains adequate for modern gaming, but newer gaming-focused CPUs with higher clocks and improved IPC pull ahead.

Virtualization

Intel Core i5-7640X X-series55

Can run modest VM loads, but core and thread count make it less ideal for multiple concurrent VMs.

Intel Core i7-7820XBest85

PCIe and memory bandwidth are helpful for multiple VMs, but core count is moderate for modern heavy virtualization needs.

Efficiency

Intel Core i5-7640X X-series59

High 112 W TDP for a quad-core design results in lower performance-per-watt than newer mainstream platforms.

Intel Core i7-7820XBest60

High 140 W TDP and 14 nm process lead to greater power consumption versus newer 7 nm and smaller nodes.

Specialized Performance

AI / ML

Intel Core i5-7640X X-seriesLimited
  • No dedicated AI acceleration; CPU-bound inference only.
  • Lacks AVX-512; limited to SSE4.1/4.2 and AVX2 instruction sets.
Intel Core i7-7820XLimited
  • No dedicated AI acceleration hardware
  • AVX-512 can help certain CPU-bound inference tasks
  • Most modern AI workloads are better served by GPUs

Content Creation

Intel Core i5-7640X X-seriesLimited
Light Photo EditingBasic Video CutsOccasional 3D
Intel Core i7-7820XVery Good
Adobe Premiere ProDaVinci ResolveBlenderCinema 4DAfter Effects

Gaming

Intel Core i5-7640X X-seriesGood
  • 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.
Intel Core i7-7820XGood
  • Capable of high-refresh gaming with a strong GPU
  • Single-core boost reaches up to 4.5 GHz on favored cores
  • Modern CPUs offer better gaming efficiency and higher IPC

Industry Impact

Gaming
Low
Moderate
Workstations
Low
High
Content Creation
Low
High
Virtualization
Low
High

Best CPU by Use Case

1080p/1440p Gaming
Good (with discrete GPU)
Light Workstation
Adequate
Overclocking Experiments
Very Good
Legacy X299 Upgrades
Good
Virtualization
Limited
Good
4K Video Editing
Very Good
3D Rendering
Very Good
Software Compilation
Very Good
Gaming
Good

Target Audience

Gamers
Targeted
Targeted
Content Creators
Targeted
Developers
Targeted
Workstation Users
Targeted
Streamers
Targeted
Office / Productivity
Students

Strengths & Weaknesses

Intel Core i5-7640X X-series

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
Intel Core i7-7820X

Pros

  • 8 cores and 16 threads for multi-threaded workloads
  • Quad-channel DDR4 memory increases bandwidth
  • 28 PCIe 3.0 lanes plus chipset lanes for expansion
  • Turbo Boost Max 3.0 for higher single-core boosts
  • AVX-512 support for optimized workloads
  • Unlocked multiplier for overclocking

Cons

  • High 140 W TDP and power consumption
  • No integrated graphics
  • Only 28 CPU PCIe lanes, limiting multi-GPU configurations
  • Discontinued platform with limited future upgrades
  • Older 14 nm process versus modern smaller nodes

Competitors & Alternatives

Intel Core i5-7640X X-series

Intel Core i7-7820X

  • AMD Ryzen 7 1800X

    Creator/Gaming

    Rival
  • AMD Ryzen 7 1700X

    Creator/Gaming

    Rival
  • AMD Ryzen Threadripper 1920X

    Workstation

    Rival
  • AMD Ryzen Threadripper 1950X

    Workstation

    Rival
  • Compare head-to-head
  • More cores, higher efficiency, and DDR5 on a modern mainstream platform.

    Compare head-to-head
  • AMD Ryzen 9 7900
    Alt

    Strong multi-threaded performance with excellent efficiency.

  • AMD Ryzen 9 5900X
    Alt

    12-core AM4 option with strong gaming and creator performance.

  • High-performance mainstream platform with good upgrade path.

    Compare head-to-head
  • AMD Ryzen Threadripper 2950X (used)
    Alt

    Higher core and lane count for workstation-class workloads.

Our Verdict on Each

A 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 review

A competent eight-core HEDT chip with strong multi-threaded performance and platform expansion, though high power draw and limited PCIe lanes compared to higher-tier X299 CPUs make it a niche choice today.

Best for: Used-market upgrade for an existing X299 build with quad-channel DDR4 and a need for more cores than mainstream.

Read the full review

Frequently Asked Questions

Which is better, Intel Core i5-7640X X-series or Intel Core i7-7820X?

Based on our editorial ratings, the Intel Core i7-7820X comes out ahead with a score of 7.5/10. 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 i5-7640X X-series or Intel Core i7-7820X?

For gaming, the Intel Core i7-7820X leads with a gaming performance score of 78/100 among Intel Core i5-7640X X-series and Intel Core i7-7820X.

Which uses less power?

The Intel Core i5-7640X X-series has the lowest rated TDP. Power draw across these chips: Intel Core i5-7640X X-series (112 W), Intel Core i7-7820X (140 W).

Do Intel Core i5-7640X X-series and Intel Core i7-7820X use the same socket?

No. They use different sockets (Intel Core i5-7640X X-series: FCLGA2066, Intel Core i7-7820X: LGA2066), so each needs a compatible motherboard.

Which has more cores?

The Intel Core i7-7820X has the most cores. Core counts: Intel Core i5-7640X X-series (4 cores), Intel Core i7-7820X (8 cores).