Athlon II X2 255 vs Phenom II X4 840

Place in performance ranking	2030	2558
Place by popularity	not in top-100	not in top-100
Cost-effectiveness evaluation	3.08	0.02
Market segment	Desktop processor	Desktop processor
Architecture codename	Propus (2009−2011)	Regor (2009−2013)
Release date	4 January 2011 (13 years ago)	25 January 2010 (14 years ago)
Launch price (MSRP)	$90	$60
Current price	$40 (0.4x MSRP)	$16.55 (0.3x MSRP)

Cost-effectiveness evaluation

Performance per price, higher is better.

Phenom II X4 840 has 15300% better value for money than Athlon II X2 255.

Detailed specifications

Phenom II X4 840 and Athlon II X2 255 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	3.2 GHz	3.1 GHz
Boost clock speed	3.2 GHz	3.1 GHz
L1 cache	128 KB (per core)	128 KB
L2 cache	512 KB (per core)	1 MB
L3 cache	0 KB	0 KB
Chip lithography	45 nm	45 nm
Die size	169 mm²	117 mm²
Number of transistors	300 million	410 million
64 bit support	+	+
Windows 11 compatibility	-	-
Unlocked multiplier	No	No

Compatibility

Information on Phenom II X4 840 and Athlon II X2 255 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	AM3	AM3
Power consumption (TDP)	95 Watt	65 Watt

Memory specs

Types, maximum amount and channel quantity of RAM supported by Phenom II X4 840 and Athlon II X2 255. Depending on the motherboard, higher memory frequencies may be supported.

Supported memory types

DDR3

Peripherals

Specifications and connection of peripherals supported by Phenom II X4 840 and Athlon II X2 255.

PCIe version

2.0

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.

Phenom II X4 840 1.55
+104%

Athlon II X2 255 0.76

Phenom II X4 840 outperforms Athlon II X2 255 by 104% based on our aggregate benchmark results.

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.

Benchmark coverage: 68%

Phenom II X4 840 2404
+105%

Athlon II X2 255 1170

Phenom II X4 840 outperforms Athlon II X2 255 by 105% in Passmark.

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.

Benchmark coverage: 42%

Phenom II X4 840 325
+0.3%

Athlon II X2 255 324

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.

Benchmark coverage: 42%

Phenom II X4 840 889
+66.5%

Athlon II X2 255 534

Phenom II X4 840 outperforms Athlon II X2 255 by 66% in GeekBench 5 Multi-Core.