Athlon II X2 255 vs Athlon X4 840

Primary details

Comparing Athlon X4 840 and Athlon II X2 255 processor market type (desktop or notebook), architecture, sales start time and price.

Place in the ranking	1873	2662
Place by popularity	not in top-100	not in top-100
Cost-effectiveness evaluation	no data	0.02
Market segment	Desktop processor	Desktop processor
Series	4x Athlon	no data
Power efficiency	3.04	1.07
Architecture codename	Kaveri (2014−2015)	Regor (2009−2013)
Release date	August 2014 (10 years ago)	25 January 2010 (14 years ago)
Launch price (MSRP)	no data	$60

Cost-effectiveness evaluation

Performance per price, higher is better.

Detailed specifications

Athlon 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	3.1 GHz	3.1 GHz
Boost clock speed	3.8 GHz	3.1 GHz
L1 cache	256K	128 KB
L2 cache	4 MB	1 MB
L3 cache	no data	0 KB
Chip lithography	28 nm	45 nm
Die size	245 mm2	117 mm2
Maximum case temperature (TCase)	72 °C	no data
Number of transistors	2,411 million	410 million
64 bit support	+	+
Windows 11 compatibility	-	-
Unlocked multiplier	+	-

Compatibility

Information on Athlon 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	Socket FM2+	AM3
Power consumption (TDP)	65 watt	65 Watt

Technologies and extensions

Technological solutions and additional instructions supported by Athlon X4 840 and Athlon II X2 255. You'll probably need this information if you require some particular technology.

AES-NI	+	-
FMA	+	-
AVX	+	-

Virtualization technologies

Virtual machine speed-up technologies supported by Athlon X4 840 and Athlon II X2 255 are enumerated here.

AMD-V

+

-

Memory specs

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

Supported memory types

DDR3

DDR3

Peripherals

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

PCIe version	3.0	2.0
PCI Express lanes	16	no data

Synthetic benchmark performance

Various benchmark results of the processors in comparison. Overall score is measured in points in 0-100 range, higher is better.

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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.

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Pros & cons summary

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Performance score	2.13	0.75
Recency	on August 2014	25 January 2010
Physical cores	4	2
Threads	4	2
Chip lithography	28 nm	45 nm

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Should you still have questions on choice between Athlon X4 840 and Athlon II X2 255, ask them in Comments section, and we shall answer.

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