Quick Verdict
A solid HEDT processor with great PCIe expansion and memory bandwidth, though limited by its 4 cores.
Overview
Launch
2012
Status
End-of-lifeGeneration
2nd Gen (Sandy Bridge-E)
Market
Desktop
The Intel Core i7-3820 is a high-end desktop (HEDT) processor based on the Sandy Bridge-E architecture. Released in early 2012, it features 4 cores and 8 threads, operating at a base clock of 3.6 GHz and a turbo boost of 3.8 GHz. Built on a 32nm process, it is part of the LGA 2011 platform, offering quad-channel DDR3 memory support and 40 PCIe 2.0 lanes. Unlike the smaller Sandy Bridge chips, the i7-3820 lacks integrated graphics, requiring a discrete GPU. It features a massive 10MB L3 cache and a 130W TDP. The processor is partially unlocked, allowing multiplier adjustments up to 45x. Though superseded by Ivy Bridge-E, the i7-3820 remains a capable chip for older workstation builds, providing excellent memory bandwidth and PCIe expansion options.
The Core i7-3820 offers 4 cores, 10MB of cache, and 40 PCIe lanes on the LGA 2011 platform. It is ideal for users needing high memory bandwidth and multi-GPU support.
Specifications
Performance
High clocks and quad-channel memory help with heavy workloads.
Good for VMs, but limited thread count.
Decent for gaming, but limited by 4 cores compared to modern CPUs.
130W TDP is high for a 4-core chip.
- •High clocks help
- •Lacks modern instruction sets
- •PCIe 2.0 limits modern GPUs
- •No AI acceleration
- •PCIe 2.0 limits modern AI accelerators
Architecture
32nm
Process Node
Sandy Bridge-E
Codename
4C / 8T
Core Config
10 MB
L3 Cache
130 W
TDP
Architecture Overview
The Sandy Bridge-E architecture represents the enthusiast and workstation tier of the 2nd generation Intel Core family. The i7-3820 uses a large 294mm² die with 1.27 billion transistors on a 32nm process. Unlike mainstream Sandy Bridge, the E variant drops the integrated graphics to free up die space for a larger L3 cache (10MB) and a quad-channel memory controller. The architecture uses a ring bus to connect the cores to the cache and PCIe lanes. It supports 40 PCIe 2.0 lanes, making it ideal for multi-GPU setups and high-speed storage. The chip is partially unlocked, allowing BCLK multiplier adjustments up to 45x. The 130W TDP reflects its high-performance desktop orientation. This architecture was designed for users needing massive memory bandwidth and I/O connectivity beyond what mainstream consumer platforms offered at the time.
CPU Design
4 cores with Hyper-Threading.
Memory Subsystem
Quad-channel DDR3 support.
PCIe & I/O
40 PCIe 2.0 lanes.
Overclocking
Partially unlocked multiplier (up to 45x).
- Better IPC
- Quad-channel memory
- 40 PCIe lanes
Key Highlights
- 40 PCIe 2.0 lanes
- Quad-channel memory
- 10MB L3 cache
- Partially unlocked
- High 130W TDP
- Only 4 cores
- No integrated graphics
- Obsolete platform
History
Launched on February 13th, 2012, the Core i7-3820 served as the entry point to Intel's premium LGA 2011 platform. While the i7-3930K and 3960X offered 6 cores, the 3820 provided a more affordable 4-core option with the same platform benefits, like quad-channel memory and 40 PCIe lanes. It was popular among enthusiasts building high-end gaming rigs and workstations who didn't need the extra cores but wanted the I/O capabilities.
The chip also featured partially unlocked multipliers, a welcome feature for overclockers. As Intel transitioned to Ivy Bridge-E and eventually Haswell-E, the LGA 2011 platform evolved, but the i7-3820 remained a solid foundation for legacy systems. Today, it is considered obsolete for new builds but holds value for users maintaining older X79-based workstations.
Improvements over Previous Generation
- Better IPC
- Quad-channel memory
- 40 PCIe lanes
Alternatives & Competitors
Should You Buy It?
Not Recommended for the right buyer
Upgrading an old X79 workstation
Avoid if…
- New builds
- Modern gaming
- Power efficiency priority
Use Cases
Interesting Facts
The entry-level chip for the LGA 2011 platform.
Features 40 PCIe 2.0 lanes, rare for a 4-core CPU.
Partially unlocked, allowing multiplier changes up to 45x.
Has a large 10MB L3 cache.
Lacks integrated graphics entirely.
Built on the 32nm Sandy Bridge-E architecture.
Supports quad-channel DDR3 memory.
Has a high 130W TDP.
Uses the massive 294mm² die.
Popular for budget multi-GPU setups in its day.
People Also Ask
Is the Core i7-3820 good for gaming?
It is okay for older games, but 4 cores limit modern gaming performance.
Is the i7-3820 unlocked?
It is partially unlocked, allowing multiplier adjustments up to 45x.
What socket does the i7-3820 use?
It uses the LGA 2011 socket.
Does the i7-3820 have integrated graphics?
No, it requires a discrete GPU.
How many PCIe lanes does the i7-3820 have?
It has 40 PCIe 2.0 lanes.
What is the TDP of the i7-3820?
The TDP is 130 Watts.
Does the i7-3820 support DDR4?
No, it supports quad-channel DDR3 memory.
What is the max turbo of the i7-3820?
It can turbo boost up to 3.8 GHz.
How much cache does the i7-3820 have?
It has 10MB of L3 cache.
Does the i7-3820 support Windows 11?
No, it is not officially supported.
Frequently Asked Questions
What generation is the i7-3820?
It is a 2nd generation Intel Core processor (Sandy Bridge-E).
Can the i7-3820 be overclocked?
Yes, it is partially unlocked up to a 45x multiplier.
What is the base clock of the i7-3820?
The base clock is 3.6 GHz.
Does it support AES-NI?
Yes, it includes hardware encryption support.
What process node is used?
It is built on a 32nm process.
What chipset does it use?
It uses the X79 chipset.
What is the maximum RAM supported?
It supports up to 64GB of DDR3 RAM.
Does it have VT-d support?
Yes, it supports Intel Virtualization Technology.
Is it better than the i7-2600K?
For multi-GPU and memory bandwidth, yes. For gaming, they are similar.
Can I use NVMe drives with the i7-3820?
Yes, via PCIe adapters, but at PCIe 2.0 speeds.