Pentium D 840 vs Athlon II X4 651
Primary details
Comparing Athlon II X4 651 and Pentium D 840 processor market type (desktop or notebook), architecture, sales start time and price.
| Place in the ranking | 1817 | not rated |
| Place by popularity | not in top-100 | not in top-100 |
| Market segment | Desktop processor | Desktop processor |
| Power efficiency | 2.14 | no data |
| Architecture codename | Llano (2011−2012) | Smithfield (2005) |
| Release date | 14 November 2011 (13 years ago) | May 2005 (19 years ago) |
Detailed specifications
Athlon II X4 651 and Pentium D 840 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 | 4 (Quad-Core) | 2 (Dual-core) |
| Threads | 4 | 2 |
| Base clock speed | 3 GHz | 3.2 GHz |
| Boost clock speed | 3 GHz | 3.2 GHz |
| L1 cache | 128 KB (per core) | 28 KB |
| L2 cache | 1 MB (per core) | 2 MB |
| L3 cache | 0 KB | 0 KB |
| Chip lithography | 32 nm | 90 nm |
| Die size | 228 mm2 | 206 mm2 |
| Maximum core temperature | no data | 70 °C |
| Number of transistors | 1,178 million | 169 million |
| 64 bit support | + | + |
| Windows 11 compatibility | - | - |
| VID voltage range | no data | 1.2V-1.4V |
Compatibility
Information on Athlon II X4 651 and Pentium D 840 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 | FM1 | PLGA775 |
| Power consumption (TDP) | 100 Watt | 130 Watt |
Technologies and extensions
Technological solutions and additional instructions supported by Athlon II X4 651 and Pentium D 840. You'll probably need this information if you require some particular technology.
| Enhanced SpeedStep (EIST) | no data | + |
| Turbo Boost Technology | no data | - |
| Hyper-Threading Technology | no data | - |
| Idle States | no data | + |
| Demand Based Switching | no data | - |
| PAE | no data | 32 Bit |
| FSB parity | no data | - |
Security technologies
Athlon II X4 651 and Pentium D 840 technologies aimed at improving security, for example, by protecting against hacks.
| TXT | no data | - |
| EDB | no data | + |
Virtualization technologies
Virtual machine speed-up technologies supported by Athlon II X4 651 and Pentium D 840 are enumerated here.
| AMD-V | + | - |
| VT-d | no data | - |
| VT-x | no data | - |
Memory specs
Types, maximum amount and channel quantity of RAM supported by Athlon II X4 651 and Pentium D 840. Depending on the motherboard, higher memory frequencies may be supported.
| Supported memory types | DDR3 | DDR1, DDR2, DDR3 |
Pros & cons summary
| Physical cores | 4 | 2 |
| Threads | 4 | 2 |
| Chip lithography | 32 nm | 90 nm |
| Power consumption (TDP) | 100 Watt | 130 Watt |
Athlon II X4 651 has 100% more physical cores and 100% more threads, a 181.3% more advanced lithography process, and 30% lower power consumption.
We couldn't decide between Athlon II X4 651 and Pentium D 840. We've got no test results to judge.
Should you still have questions on choice between Athlon II X4 651 and Pentium D 840, ask them in Comments section, and we shall answer.
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