Xeon E5645 vs i7-6900K
Aggregate performance score
Core i7-6900K outperforms Xeon E5645 by a whopping 186% based on our aggregate benchmark results.
Primary details
Comparing Core i7-6900K and Xeon E5645 processor market type (desktop or notebook), architecture, sales start time and price.
| Place in the ranking | 842 | 1618 |
| Place by popularity | not in top-100 | not in top-100 |
| Cost-effectiveness evaluation | 1.04 | 1.38 |
| Market segment | Desktop processor | Server |
| Power efficiency | 6.16 | 3.76 |
| Architecture codename | Broadwell-E (2016) | Westmere-EP (2010−2011) |
| Release date | 31 May 2016 (8 years ago) | 16 March 2010 (14 years ago) |
| Launch price (MSRP) | $1,020 | $294 |
Cost-effectiveness evaluation
Performance per price, higher is better.
Xeon E5645 has 33% better value for money than i7-6900K.
Detailed specifications
Core i7-6900K and Xeon E5645 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 | 8 (Octa-Core) | 6 (Hexa-Core) |
| Threads | 16 | 12 |
| Base clock speed | 3.2 GHz | 2.4 GHz |
| Boost clock speed | 4 GHz | 2.67 GHz |
| L1 cache | 32 KB (per core) | 64 KB (per core) |
| L2 cache | 256 KB (per core) | 256 KB (per core) |
| L3 cache | 20 MB (shared) | 12 MB (shared) |
| Chip lithography | 14 nm | 32 nm |
| Die size | no data | 239 mm2 |
| Maximum core temperature | no data | 76 °C |
| Maximum case temperature (TCase) | 72 °C | no data |
| Number of transistors | no data | 1,170 million |
| 64 bit support | + | + |
| Windows 11 compatibility | - | - |
| Unlocked multiplier | + | - |
Compatibility
Information on Core i7-6900K and Xeon E5645 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 | 2 |
| Socket | FCLGA2011 | FCLGA1366,LGA1366 |
| Power consumption (TDP) | 140 Watt | 80 Watt |
Technologies and extensions
Technological solutions and additional instructions supported by Core i7-6900K and Xeon E5645. You'll probably need this information if you require some particular technology.
| Instruction set extensions | no data | Intel® SSE4.2 |
| AES-NI | + | + |
| AVX | + | - |
| Enhanced SpeedStep (EIST) | + | + |
| Turbo Boost Technology | 2.0 | 1.0 |
| Hyper-Threading Technology | + | + |
| Idle States | + | + |
| Smart Response | + | no data |
| Demand Based Switching | no data | + |
| PAE | no data | 40 Bit |
| Turbo Boost Max 3.0 | + | no data |
Security technologies
Core i7-6900K and Xeon E5645 technologies aimed at improving security, for example, by protecting against hacks.
| TXT | + | + |
| EDB | + | + |
Virtualization technologies
Virtual machine speed-up technologies supported by Core i7-6900K and Xeon E5645 are enumerated here.
| VT-d | + | + |
| VT-x | + | + |
| EPT | + | + |
Memory specs
Types, maximum amount and channel quantity of RAM supported by Core i7-6900K and Xeon E5645. Depending on the motherboard, higher memory frequencies may be supported.
| Supported memory types | DDR4 | DDR3 |
| Maximum memory size | 128 GB | 288 GB |
| Max memory channels | 4 | 3 |
| Maximum memory bandwidth | no data | 32 GB/s |
| ECC memory support | - | + |
Peripherals
Specifications and connection of peripherals supported by Core i7-6900K and Xeon E5645.
| PCIe version | 3.0 | 2.0 |
| PCI Express lanes | 40 | no data |
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 | 9.11 | 3.18 |
| Recency | 31 May 2016 | 16 March 2010 |
| Physical cores | 8 | 6 |
| Threads | 16 | 12 |
| Chip lithography | 14 nm | 32 nm |
| Power consumption (TDP) | 140 Watt | 80 Watt |
i7-6900K has a 186.5% higher aggregate performance score, an age advantage of 6 years, 33.3% more physical cores and 33.3% more threads, and a 128.6% more advanced lithography process.
Xeon E5645, on the other hand, has 75% lower power consumption.
The Core i7-6900K is our recommended choice as it beats the Xeon E5645 in performance tests.
Note that Core i7-6900K is a desktop processor while Xeon E5645 is a server/workstation one.
Should you still have questions on choice between Core i7-6900K and Xeon E5645, ask them in Comments section, and we shall answer.
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