Athlon II X4 645 vs Xeon 6521P
Aggregate performance score
Xeon 6521P outperforms Athlon II X4 645 by a whopping 2620% based on our aggregate benchmark results.
Contents
Primary details
Comparing processor market type (desktop or notebook), architecture, sales start time and price.
| Place in the ranking | 104 | 2432 |
| Place by popularity | not in top-100 | not in top-100 |
| Cost-effectiveness evaluation | 33.98 | 3.30 |
| Market segment | Server | Desktop processor |
| Power efficiency | 17.50 | 1.52 |
| Designer | Intel | AMD |
| Manufacturer | Intel | no data |
| Architecture codename | Granite Rapids (2024−2025) | Propus (2009−2011) |
| Release date | 24 February 2025 (less than a year ago) | 21 September 2010 (15 years ago) |
| Launch price (MSRP) | $1,250 | $80 |
Cost-effectiveness evaluation
Performance per price, higher is better.
Xeon 6521P has 930% better value for money than Athlon II X4 645.
Performance to price scatter graph
Detailed specifications
Xeon 6521P and Athlon II X4 645 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 | 24 (Tetracosa-Core) | 4 (Quad-Core) |
| Threads | 48 | 4 |
| Base clock speed | 2.6 GHz | 3.1 GHz |
| Boost clock speed | 4.1 GHz | 3.1 GHz |
| L1 cache | 112 KB (per core) | 128 KB (per core) |
| L2 cache | 2 MB (per core) | 512 KB (per core) |
| L3 cache | 144 MB (shared) | 0 KB |
| Chip lithography | Intel 3 nm | 45 nm |
| Die size | 598 mm2 | 169 mm2 |
| Maximum case temperature (TCase) | 82 °C | no data |
| Number of transistors | no data | 300 million |
| 64 bit support | + | + |
| Windows 11 compatibility | no data | - |
Compatibility
Information on Xeon 6521P and Athlon II X4 645 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 | FCLGA4710 | AM3 |
| Power consumption (TDP) | 225 Watt | 95 Watt |
Technologies and extensions
Technological solutions and additional instructions supported by Xeon 6521P and Athlon II X4 645. You'll probably need this information if you require some particular technology.
| Instruction set extensions | Intel® SSE4.2, Intel® AVX, Intel® AVX2, Intel® AVX-512, Intel® AMX | no data |
| AES-NI | + | - |
| AVX | + | - |
| Enhanced SpeedStep (EIST) | + | no data |
| Speed Shift | + | no data |
| Turbo Boost Technology | 2.0 | no data |
| Hyper-Threading Technology | + | no data |
| TSX | + | - |
| Deep Learning Boost | + | - |
Security technologies
Xeon 6521P and Athlon II X4 645 technologies aimed at improving security, for example, by protecting against hacks.
| TXT | + | no data |
| EDB | + | no data |
| SGX | + | no data |
| OS Guard | + | no data |
Virtualization technologies
Virtual machine speed-up technologies supported by Xeon 6521P and Athlon II X4 645 are enumerated here.
| VT-d | + | no data |
| VT-x | + | no data |
| EPT | + | no data |
Memory specs
Types, maximum amount and channel quantity of RAM supported by Xeon 6521P and Athlon II X4 645. Depending on the motherboard, higher memory frequencies may be supported.
| Supported memory types | DDR5(6400MT/s) | DDR3 |
| Maximum memory size | 4 TB | no data |
| Max memory channels | 8 | no data |
| ECC memory support | + | - |
Graphics specifications
General parameters of integrated GPUs, if any.
| Integrated graphics card | N/A | no data |
Peripherals
Specifications and connection of peripherals supported by Xeon 6521P and Athlon II X4 645.
| PCIe version | 5.0 | 2.0 |
| PCI Express lanes | 136 | no data |
Synthetic benchmarks
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.
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. Other than that, Passmark measures multi-core performance.
Pros & cons summary
| Performance score | 36.72 | 1.35 |
| Recency | 24 February 2025 | 21 September 2010 |
| Physical cores | 24 | 4 |
| Threads | 48 | 4 |
| Power consumption (TDP) | 225 Watt | 95 Watt |
Xeon 6521P has a 2620% higher aggregate performance score, an age advantage of 14 years, and 500% more physical cores and 1100% more threads.
Athlon II X4 645, on the other hand, has 136.8% lower power consumption.
The Intel Xeon 6521P is our recommended choice as it beats the AMD Athlon II X4 645 in performance tests.
Be aware that Xeon 6521P is a server/workstation processor while Athlon II X4 645 is a desktop one.
Other comparisons
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