i5-8400T vs Athlon II X2 255
Aggregate performance score
Core i5-8400T outperforms Athlon II X2 255 by a whopping 534% based on our aggregate benchmark results.
Primary details
Comparing Athlon II X2 255 and Core i5-8400T processor market type (desktop or notebook), architecture, sales start time and price.
| Place in the ranking | 2665 | 1270 |
| Place by popularity | not in top-100 | not in top-100 |
| Cost-effectiveness evaluation | 0.02 | 5.07 |
| Market segment | Desktop processor | Desktop processor |
| Series | no data | Intel Core i5 |
| Power efficiency | 1.08 | 12.68 |
| Architecture codename | Regor (2009−2013) | Coffee Lake (2017−2019) |
| Release date | 25 January 2010 (14 years ago) | 2 April 2018 (6 years ago) |
| Launch price (MSRP) | $60 | $182 |
Cost-effectiveness evaluation
Performance per price, higher is better.
i5-8400T has 25250% better value for money than Athlon II X2 255.
Detailed specifications
Athlon II X2 255 and Core i5-8400T 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 | 2 (Dual-core) | 6 (Hexa-Core) |
| Threads | 2 | 6 |
| Base clock speed | 3.1 GHz | 1.7 GHz |
| Boost clock speed | 3.1 GHz | 3.3 GHz |
| Bus type | no data | DMI 3.0 |
| Bus rate | no data | 4 × 8 GT/s |
| Multiplier | no data | 17 |
| L1 cache | 128 KB | 64K (per core) |
| L2 cache | 1 MB | 256K (per core) |
| L3 cache | 0 KB | 9 MB (shared) |
| Chip lithography | 45 nm | 14 nm |
| Die size | 117 mm2 | 149 mm2 |
| Maximum core temperature | no data | 100 °C |
| Maximum case temperature (TCase) | no data | 72 °C |
| Number of transistors | 410 million | no data |
| 64 bit support | + | + |
| Windows 11 compatibility | - | + |
Compatibility
Information on Athlon II X2 255 and Core i5-8400T 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 (Uniprocessor) |
| Socket | AM3 | FCLGA1151 |
| Power consumption (TDP) | 65 Watt | 35 Watt |
Technologies and extensions
Technological solutions and additional instructions supported by Athlon II X2 255 and Core i5-8400T. You'll probably need this information if you require some particular technology.
| Instruction set extensions | no data | Intel® SSE4.1, Intel® SSE4.2, Intel® AVX2 |
| AES-NI | - | + |
| AVX | - | + |
| Enhanced SpeedStep (EIST) | no data | + |
| Turbo Boost Technology | no data | 2.0 |
| Hyper-Threading Technology | no data | - |
| Idle States | no data | + |
| Thermal Monitoring | - | + |
Security technologies
Athlon II X2 255 and Core i5-8400T technologies aimed at improving security, for example, by protecting against hacks.
| TXT | no data | - |
| EDB | no data | + |
| Secure Key | no data | + |
| MPX | - | + |
| Identity Protection | - | + |
| SGX | no data | Yes with Intel® ME |
| OS Guard | no data | + |
Virtualization technologies
Virtual machine speed-up technologies supported by Athlon II X2 255 and Core i5-8400T 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 Athlon II X2 255 and Core i5-8400T. Depending on the motherboard, higher memory frequencies may be supported.
| Supported memory types | DDR3 | DDR4-2666 |
| Maximum memory size | no data | 128 GB |
| Max memory channels | no data | 2 |
| Maximum memory bandwidth | no data | 42.671 GB/s |
Graphics specifications
General parameters of integrated GPUs, if any.
| Integrated graphics card | no data | Intel UHD Graphics 630 |
| Max video memory | no data | 64 GB |
| Quick Sync Video | - | + |
| Clear Video | no data | + |
| Clear Video HD | no data | + |
| Graphics max frequency | no data | 1.05 GHz |
| InTru 3D | no data | + |
Graphics interfaces
Available interfaces and connections of Athlon II X2 255 and Core i5-8400T integrated GPUs.
| Number of displays supported | no data | 3 |
Graphics image quality
Maximum display resolutions supported by Athlon II X2 255 and Core i5-8400T integrated GPUs, including resolutions over different interfaces.
| 4K resolution support | no data | + |
| Max resolution over HDMI 1.4 | no data | 4096x2304@24Hz |
| Max resolution over eDP | no data | 4096x2304@60Hz |
| Max resolution over DisplayPort | no data | 4096x2304@60Hz |
Graphics API support
APIs supported by Athlon II X2 255 and Core i5-8400T integrated GPUs, sometimes API versions are included.
| DirectX | no data | 12 |
| OpenGL | no data | 4.5 |
Peripherals
Specifications and connection of peripherals supported by Athlon II X2 255 and Core i5-8400T.
| PCIe version | 2.0 | 3.0 |
| PCI Express lanes | no data | 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 | 0.74 | 4.69 |
| Recency | 25 January 2010 | 2 April 2018 |
| Physical cores | 2 | 6 |
| Threads | 2 | 6 |
| Chip lithography | 45 nm | 14 nm |
| Power consumption (TDP) | 65 Watt | 35 Watt |
i5-8400T has a 533.8% higher aggregate performance score, an age advantage of 8 years, 200% more physical cores and 200% more threads, a 221.4% more advanced lithography process, and 85.7% lower power consumption.
The Core i5-8400T is our recommended choice as it beats the Athlon II X2 255 in performance tests.
Should you still have questions on choice between Athlon II X2 255 and Core i5-8400T, ask them in Comments section, and we shall answer.
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