i9-11900K vs Xeon E5645
Aggregate performance score
i9-11900K outperforms Xeon E5645 by a whopping 401% based on our aggregate benchmark results.
Primary details
Comparing Xeon E5645 and Core i9-11900K processor market type (desktop or notebook), architecture, sales start time and price.
| Place in performance ranking | 1571 | 402 |
| Place by popularity | not in top-100 | not in top-100 |
| Cost-effectiveness evaluation | 3.19 | 19.64 |
| Market segment | Server | Desktop processor |
| Architecture codename | Westmere-EP (2010−2011) | Rocket Lake (2021) |
| Release date | 16 March 2010 (14 years ago) | 16 March 2021 (3 years ago) |
| Launch price (MSRP) | $294 | $539 |
Cost-effectiveness evaluation
Performance per price, higher is better.
i9-11900K has 516% better value for money than Xeon E5645.
Detailed specifications
Xeon E5645 and Core i9-11900K 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) | 8 (Octa-Core) |
| Threads | 12 | 16 |
| Base clock speed | 2.4 GHz | 3.5 GHz |
| Boost clock speed | 2.67 GHz | 5.2 GHz |
| Bus rate | no data | 8 GT/s |
| L1 cache | 64 KB (per core) | 80 KB (per core) |
| L2 cache | 256 KB (per core) | 512 KB (per core) |
| L3 cache | 12 MB (shared) | 16 MB (shared) |
| Chip lithography | 32 nm | 14 nm |
| Die size | 239 mm2 | 276 mm2 |
| Maximum core temperature | 76 °C | 100 °C |
| Maximum case temperature (TCase) | no data | 72 °C |
| Number of transistors | 1,170 million | no data |
| 64 bit support | + | + |
| Windows 11 compatibility | - | + |
| Unlocked multiplier | - | + |
Compatibility
Information on Xeon E5645 and Core i9-11900K 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 | 2 | 1 |
| Socket | FCLGA1366,LGA1366 | FCLGA1200 |
| Power consumption (TDP) | 80 Watt | 125 Watt |
Technologies and extensions
Technological solutions and additional instructions supported by Xeon E5645 and Core i9-11900K. You'll probably need this information if you require some particular technology.
| Instruction set extensions | Intel® SSE4.2 | Intel® SSE4.1, Intel® SSE4.2, Intel® AVX2, Intel® AVX-512 |
| AES-NI | + | + |
| AVX | - | + |
| vPro | no data | + |
| Enhanced SpeedStep (EIST) | + | + |
| Turbo Boost Technology | 1.0 | 2.0 |
| Hyper-Threading Technology | + | + |
| TSX | - | + |
| Idle States | + | + |
| Thermal Monitoring | - | + |
| SIPP | - | + |
| Demand Based Switching | + | no data |
| PAE | 40 Bit | no data |
| Turbo Boost Max 3.0 | no data | + |
| Status | Discontinued | Discontinued |
| Deep Learning Boost | - | + |
Security technologies
Xeon E5645 and Core i9-11900K technologies aimed at improving security, for example, by protecting against hacks.
| TXT | + | + |
| EDB | + | + |
| Secure Key | no data | + |
| Identity Protection | - | + |
| SGX | no data | - |
| OS Guard | no data | + |
Virtualization technologies
Virtual machine speed-up technologies supported by Xeon E5645 and Core i9-11900K are enumerated here.
| VT-d | + | + |
| VT-x | + | + |
| EPT | + | + |
Memory specs
Types, maximum amount and channel quantity of RAM supported by Xeon E5645 and Core i9-11900K. Depending on the motherboard, higher memory frequencies may be supported.
| Supported memory types | DDR3 | DDR4 |
| Maximum memory size | 288 GB | 128 GB |
| Max memory channels | 3 | 2 |
| Maximum memory bandwidth | 32 GB/s | 50 GB/s |
| ECC memory support | + | - |
Graphics specifications
General parameters of integrated GPUs, if any.
| Integrated graphics card | no data | Intel UHD Graphics 750 |
| Max video memory | no data | 64 GB |
| Quick Sync Video | - | + |
| Clear Video | no data | + |
| Clear Video HD | no data | + |
| Graphics max frequency | no data | 1.3 GHz |
| Execution Units | no data | 32 |
| InTru 3D | no data | + |
Graphics interfaces
Available interfaces and connections of Xeon E5645 and Core i9-11900K integrated GPUs.
| Number of displays supported | no data | 3 |
Graphics image quality
Maximum display resolutions supported by Xeon E5645 and Core i9-11900K integrated GPUs, including resolutions over different interfaces.
| 4K resolution support | no data | + |
| Max resolution over HDMI 1.4 | no data | 4096x2160@60Hz |
| Max resolution over eDP | no data | 5120 x 3200 @60Hz |
| Max resolution over DisplayPort | no data | 5120 x 3200 @60Hz |
Graphics API support
APIs supported by Xeon E5645 and Core i9-11900K integrated GPUs, sometimes API versions are included.
| DirectX | no data | 12.1 |
| OpenGL | no data | 4.5 |
Peripherals
Specifications and connection of peripherals supported by Xeon E5645 and Core i9-11900K.
| PCIe version | 2.0 | 4.0 |
| PCI Express lanes | no data | 20 |
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 | 3.26 | 16.33 |
| Recency | 16 March 2010 | 16 March 2021 |
| Physical cores | 6 | 8 |
| Threads | 12 | 16 |
| Chip lithography | 32 nm | 14 nm |
| Power consumption (TDP) | 80 Watt | 125 Watt |
Xeon E5645 has 56.3% lower power consumption.
i9-11900K, on the other hand, has a 400.9% higher aggregate performance score, an age advantage of 11 years, 33.3% more physical cores and 33.3% more threads, and a 128.6% more advanced lithography process.
The Core i9-11900K is our recommended choice as it beats the Xeon E5645 in performance tests.
Be aware that Xeon E5645 is a server/workstation processor while Core i9-11900K is a desktop one.
Should you still have questions on choice between Xeon E5645 and Core i9-11900K, ask them in Comments section, and we shall answer.
Similar processor comparisons
We picked several similar comparisons of processors in the same market segment and performance relatively close to those reviewed on this page.
