Xeon X5647 vs E5645

Primary details

Comparing Xeon E5645 and Xeon X5647 processor market type (desktop or notebook), architecture, sales start time and price.

Place in the ranking	1618	1684
Place by popularity	not in top-100	not in top-100
Cost-effectiveness evaluation	1.38	1.78
Market segment	Server	Server
Power efficiency	3.76	2.04
Architecture codename	Westmere-EP (2010−2011)	Westmere-EP (2010−2011)
Release date	16 March 2010 (14 years ago)	14 February 2011 (13 years ago)
Launch price (MSRP)	$294	$175

Cost-effectiveness evaluation

Performance per price, higher is better.

Xeon X5647 has 29% better value for money than Xeon E5645.

Detailed specifications

Xeon E5645 and Xeon X5647 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	6 (Hexa-Core)	4 (Quad-Core)
Threads	12	8
Base clock speed	2.4 GHz	2.93 GHz
Boost clock speed	2.67 GHz	3.2 GHz
L1 cache	64 KB (per core)	64 KB (per core)
L2 cache	256 KB (per core)	256 KB (per core)
L3 cache	12 MB (shared)	12 MB (shared)
Chip lithography	32 nm	32 nm
Die size	239 mm2	239 mm2
Maximum core temperature	76 °C	80 °C
Number of transistors	1,170 million	1,170 million
64 bit support	+	+
Windows 11 compatibility	-	-

Compatibility

Information on Xeon E5645 and Xeon X5647 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	2	2
Socket	FCLGA1366,LGA1366	FCLGA1366,LGA1366
Power consumption (TDP)	80 Watt	130 Watt

Technologies and extensions

Technological solutions and additional instructions supported by Xeon E5645 and Xeon X5647. You'll probably need this information if you require some particular technology.

Instruction set extensions	Intel® SSE4.2	Intel® SSE4.2
AES-NI	+	+
Enhanced SpeedStep (EIST)	+	+
Turbo Boost Technology	1.0	1.0
Hyper-Threading Technology	+	+
Idle States	+	+
Demand Based Switching	+	+
PAE	40 Bit	40 Bit

Security technologies

Xeon E5645 and Xeon X5647 technologies aimed at improving security, for example, by protecting against hacks.

TXT	+	+
EDB	+	+

Virtualization technologies

Virtual machine speed-up technologies supported by Xeon E5645 and Xeon X5647 are enumerated here.

VT-d	+	+
VT-x	+	+
EPT	+	+

Memory specs

Types, maximum amount and channel quantity of RAM supported by Xeon E5645 and Xeon X5647. Depending on the motherboard, higher memory frequencies may be supported.

Supported memory types	DDR3	DDR3
Maximum memory size	288 GB	288 GB
Max memory channels	3	3
Maximum memory bandwidth	32 GB/s	25.6 GB/s
ECC memory support	+	+

Peripherals

Specifications and connection of peripherals supported by Xeon E5645 and Xeon X5647.

PCIe version

2.0

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.

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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	3.18	2.80
Recency	16 March 2010	14 February 2011
Physical cores	6	4
Threads	12	8
Power consumption (TDP)	80 Watt	130 Watt

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Should you still have questions on choice between Xeon E5645 and Xeon X5647, ask them in Comments section, and we shall answer.

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