i5-661 vs i7-5820K
Aggregate performance score
Core i7-5820K outperforms Core i5-661 by a whopping 300% based on our aggregate benchmark results.
Primary details
Comparing Core i7-5820K and Core i5-661 processor market type (desktop or notebook), architecture, sales start time and price.
| Place in the ranking | 1076 | 2112 |
| Place by popularity | not in top-100 | not in top-100 |
| Cost-effectiveness evaluation | 1.07 | 0.08 |
| Market segment | Desktop processor | Desktop processor |
| Power efficiency | 4.19 | 1.69 |
| Architecture codename | Haswell-E (2014) | Clarkdale (2010−2011) |
| Release date | 1 September 2014 (10 years ago) | 7 January 2010 (14 years ago) |
| Launch price (MSRP) | $410 | $252 |
Cost-effectiveness evaluation
Performance per price, higher is better.
i7-5820K has 1238% better value for money than i5-661.
Detailed specifications
Core i7-5820K and Core i5-661 basic parameters such as number of cores, number of threads, base frequency and turbo boost clock, lithography, cache size and multiplier lock state. These parameters indirectly say of CPU speed, though for more precise assessment you have to consider their test results.
| Physical cores | 6 (Hexa-Core) | 2 (Dual-core) |
| Threads | 12 | 4 |
| Base clock speed | 3.3 GHz | 3.33 GHz |
| Boost clock speed | 3.6 GHz | 3.6 GHz |
| Bus rate | 0 GT/s | 2.5 GT/s |
| L1 cache | 64 KB (per core) | 64 KB (per core) |
| L2 cache | 256 KB (per core) | 256 KB (per core) |
| L3 cache | 15 MB (shared) | 4 MB (shared) |
| Chip lithography | 22 nm | 32 nm |
| Die size | 356 mm2 | 81 mm2 |
| Maximum core temperature | 67 °C | 70 °C |
| Number of transistors | 2,600 million | 382 million |
| 64 bit support | + | + |
| Windows 11 compatibility | - | - |
| Unlocked multiplier | + | - |
Compatibility
Information on Core i7-5820K and Core i5-661 compatibility with other computer components: motherboard (look for socket type), power supply unit (look for power consumption) etc. Useful when planning a future computer configuration or upgrading an existing one. Note that power consumption of some processors can well exceed their nominal TDP, even without overclocking. Some can even double their declared thermals given that the motherboard allows to tune the CPU power parameters.
| Number of CPUs in a configuration | 1 | 1 |
| Socket | FCLGA2011 | FCLGA1156 |
| Power consumption (TDP) | 140 Watt | 87 Watt |
Technologies and extensions
Technological solutions and additional instructions supported by Core i7-5820K and Core i5-661. You'll probably need this information if you require some particular technology.
| Instruction set extensions | Intel® SSE4.2, Intel® AVX2 | Intel® SSE4.2 |
| AES-NI | + | + |
| AVX | + | - |
| Enhanced SpeedStep (EIST) | + | + |
| Turbo Boost Technology | 2.0 | 1.0 |
| Hyper-Threading Technology | + | + |
| TSX | + | - |
| Idle States | + | + |
| Thermal Monitoring | + | - |
| Smart Response | + | no data |
| Demand Based Switching | - | - |
| PAE | no data | 36 Bit |
| FDI | no data | + |
Security technologies
Core i7-5820K and Core i5-661 technologies aimed at improving security, for example, by protecting against hacks.
| TXT | + | + |
| EDB | + | + |
| Identity Protection | + | - |
Virtualization technologies
Virtual machine speed-up technologies supported by Core i7-5820K and Core i5-661 are enumerated here.
| VT-d | + | + |
| VT-x | + | + |
| EPT | + | + |
Memory specs
Types, maximum amount and channel quantity of RAM supported by Core i7-5820K and Core i5-661. Depending on the motherboard, higher memory frequencies may be supported.
| Supported memory types | DDR4 | DDR3 |
| Maximum memory size | 64 GB | 16.38 GB |
| Max memory channels | 4 | 2 |
| Maximum memory bandwidth | 68 GB/s | 21 GB/s |
Graphics specifications
General parameters of integrated GPUs, if any.
| Integrated graphics card | no data | Intel® HD Graphics for Previous Generation Intel® Processors |
| Clear Video HD | no data | + |
Graphics interfaces
Available interfaces and connections of Core i7-5820K and Core i5-661 integrated GPUs.
| Number of displays supported | no data | 2 |
Peripherals
Specifications and connection of peripherals supported by Core i7-5820K and Core i5-661.
| PCIe version | 3.0 | 2.0 |
| PCI Express lanes | 28 | 16 |
Synthetic benchmark performance
Various benchmark results of the processors in comparison. Overall score is measured in points in 0-100 range, higher is better.
Combined synthetic benchmark score
This is our combined benchmark performance rating. We are regularly improving our combining algorithms, but if you find some perceived inconsistencies, feel free to speak up in comments section, we usually fix problems quickly.
Passmark
Passmark CPU Mark is a widespread benchmark, consisting of 8 different types of workload, including integer and floating point math, extended instructions, compression, encryption and physics calculation. There is also one separate single-threaded scenario measuring single-core performance.
GeekBench 5 Single-Core
GeekBench 5 Single-Core is a cross-platform application developed in the form of CPU tests that independently recreate certain real-world tasks with which to accurately measure performance. This version uses only a single CPU core.
GeekBench 5 Multi-Core
GeekBench 5 Multi-Core is a cross-platform application developed in the form of CPU tests that independently recreate certain real-world tasks with which to accurately measure performance. This version uses all available CPU cores.
Pros & cons summary
| Performance score | 6.20 | 1.55 |
| Recency | 1 September 2014 | 7 January 2010 |
| Physical cores | 6 | 2 |
| Threads | 12 | 4 |
| Chip lithography | 22 nm | 32 nm |
| Power consumption (TDP) | 140 Watt | 87 Watt |
i7-5820K has a 300% higher aggregate performance score, an age advantage of 4 years, 200% more physical cores and 200% more threads, and a 45.5% more advanced lithography process.
i5-661, on the other hand, has 60.9% lower power consumption.
The Core i7-5820K is our recommended choice as it beats the Core i5-661 in performance tests.
Should you still have questions on choice between Core i7-5820K and Core i5-661, ask them in Comments section, and we shall answer.
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