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AMD Athlon II X4 645 3.1GHz Socket AM3 Quad-Core Processor Review

AMD Athlon II X4 645 3.1GHz Socket AM3 Quad-Core Processor Review - PCSTATS
Price Check: $/£/€
Abstract: In this review PCSTATS is testing AMD's latest mainstream quad-core chip, the 3.1GHz Athlon II X4 645 processor. Architecturally speaking the Athlon II X4 645 is identical to the preceding Athlon II X4 635 model, except for a modest clock speed increase.
 80% Rating:   
Filed under: CPU / Processors Published:  Author: 
External Mfg. Website: AMD Sep 22 2010   A. Edmond  
Home > Reviews > CPU / Processors > AMD Athlon II X4 645

In this review PCSTATS is testing AMD's latest mainstream quad-core chip, the 3.1GHz Athlon II X4 645 processor. Architecturally speaking the Athlon II X4 645 is identical to the preceding Athlon II X4 635 model, except for a modest clock speed increase. If you're familiar with the preceding few Athlon II X4 6-series CPUs you'll know what to expect so jump ahead to the overclocking results and benchmark tables.

Bringing the AII X4's four cores past the 3GHz threshold affords incremental gains of course, and the Athlon II X4 continues to be an ideal CPU for media PCs, particularly when paired an AMD 890GX motherboard. If faced off against an Intel Core i5 or AMD Phenom II X4 chip the Athlon II X4 family will bring up the rear, but if you're in need of a good all-around home PC system and don't have much cash to splash around the platform offers exceptional value.

AMD's Athlon II X4 645 is a native socket AM3 processor and is backwards compatible with older socket AM2+ motherboards, an element that is clearly missing from Intel's expanding circus of sockets. Just like the flagship processors, the Athlon II X4 645 will support 32-bit or 64-bit versions of Microsoft Windows 7/Vista/XP operating system, but best of all it's priced at an economical $122USD.

On the spec front, AMD's 3.1GHz Athlon II X4 645 processor features 512KB of L2 cache for each of its four cores, for a total of 2MB. Unlike the Phenom II quad-core designs, the Athlon II X4 lacks any L3 cache. Platform compatibility is broad thanks to both DDR2 and DDR3 onboard memory controllers, making it possible to install this processor on motherboards that support DDR2-1066 or DDR3-1333 memory. For this review PCSTATS has selected the ASUS Crosshair IV Forumla (890FX) motherboard and 4GB of Corsair XMS3-1600C9 DDR3 RAM. If you're building a new PC it's wise to go the DDR3-route as DDR2 is being phased out.

AMD Athlon II X4 645 Processor
Tech Specs

Athlon II X4 645
(4 core / 4 thread)

Clock: 3.11GHz
L1: (4x) 128KB
L2: (4x) 512KB
L3: none
Multiplier: 15.5x
Package: 938-pin
Socket: AM3 mPGA
Core: 45nm DSL SOI
Transistor: ~300M
Die Size; 169mm2
Power: 95W
Codename: 'Propus'
Cost: $122 USD



Manufactured on a 45nm SOI process at the Global Foundries Fab 1 module in Dresden Germany, the Athlon II X4 645 is built on AMDs "Propus" core - essentially a slimmed-down version of "Deneb" that's been around since first Phenom II processor. This core design consists of four individual computational cores (4-core, 4-thread) with 512KB of L2 cache for each. The monolithic silicon die measures 169mm2 and contains 300 million transistors. Thermal Design Power (TDP) sits at a moderate 95W.

As you might expect, the 3.1GHz Athlon II X4 645 processor supports full hardware virtualization, so individual cores can be assigned to virtual machines. Built in virtualization is one of the big features of Microsoft Windows 7, and it is this that makes running Windows XP Mode inside of the Windows 7 operating system possible.

Retailing at launch for$122 CDN ($122 USD, £75 GBP) , the Athlon II X4 645 processor continues to be one of the most affordable quad-core CPUs on the market. Its primary competition will be coming from AMD's own Phenom II X3 processors and Intel's Core i5 processors.

Athlon II = No L3 Cache

Fast L3 cache is important for communication between processor cores and multi-threading efficiency. When all four cores are busy processing threads the L3 cache acts as sort of a pool that feeds the individual L2 caches. Ultimately the absence of L3 cache in the Athlon II family of processors increases the frequency that the chip has to fetch information from system memory or virtual memory (hard drive), both of which are orders of magnitude slower than accessing quick on-die L3 cache.

In applications which rely on streaming a lot of data into all four cores of the computer processor from memory, the lack of L3 cache will hamper the AMD Athlon II X4 645 processor's performance compared to equivalently paced quad-core Phenom II chips.

Let's see how this Athlon II compares in the very competitive mainstream processor field. First up a quick look at power consumption then PCSTATS will head straight into overclocking and then our extensive benchmark set.

Core-by-Core CPU Power Draw

CPU power draw (expressed in Watts) can be easily measured by way of total system power if you have a simple electrical power meter. To determine how much juice the CPU is consuming, we only need to compare power draw with the processor resting at idle, and with each core at 100% CPU utilization. For an accurate measurement it's necessary to disable power saving features and CPU clock speed throttling technologies like Cool 'n' Quiet, EIST (speedstep) and C1E power states, etc. To stress each core in the processor individually, PCSTATS uses a free program called Stress Prime SP2004).

The power draw for the entire PC system is measured with an Extech Power Analyzer Datalogger (model 380803). Given that motherboards vary across these test systems this is not a pure measure of CPU power draw alone, but rather a measurement of the total computer system power draw, which we can compare for each specific platforms between the CPU idle and CPU stressed states

Total System Idle Power Draw
Processor Total System Power Draw
Intel Pentium 4 540 150 Watts
Intel Pentium D 840 165 Watts
Intel Pentium D 940 168 Watts
Intel Core 2 Duo E6600 117 Watts
Intel Core 2 Duo E6750 123 Watts
Intel Core 2 Duo E8400 131 Watts
Intel Core 2 Duo E8500 114 Watts
Intel Core i5 750 124 Watts
Intel Core i7 920 144 Watts
AMD Sempron 3600+ 120 Watts
AMD Athlon64 4000+ 163 Watts
AMD Athlon64 FX-60 127 Watts
AMD Athlon64 X2 4800+ 143 Watts
AMD Athlon64 X2 5000+ 156 Watts
AMD Athlon64 FX-62 168 Watts
AMD Athlon II X2 240e 122 Watts
AMD Athlon II X2 250 128 Watts
AMD Athlon II X3 435 128 Watts
AMD Athlon II X4 620 130 Watts
AMD Athlon II X4 635 127 Watts
AMD Athlon II X4 645 120 Watts
AMD Phenom II X2 550 BE 145 Watts
AMD Phenom II X2 555 BE 143 Watts
AMD Phenom II X3 720 BE 155 Watts
AMD Phenom II X4 910e 131 Watts
AMD Phenom II X4 955 BE (125W) 148 Watts
AMD Phenom II X4 965 BE (125W) 150 Watts
AMD Phenom II X4 965 BE (140W) 150 Watts
AMD Phenom II X4 BE 970BE 134 Watts
AMD Phenom II X6 BE 1075T 129 Watts
AMD Phenom II X6 BE 1090T 130 Watts

Even with a couple hundred extra MHz under the hood, the Athlon II X4 645 PC system idles at 120 Watts, a hair lower than the AII X4 635 and 620 models. We'll see where the power draw figures stand once the system is under stress, for each of the Athlon II X4 645's four processing cores...

Total System Stressed Power Draw - All Cores/Threads
Processor Total System Power Draw (All Cores)
Intel Pentium 4 540 223 Watts
Intel Pentium D 840 (2 Core ) 240 Watts
Intel Pentium D 940 (2 Core Load) 253 Watts
Intel Core 2 Duo E6600 (2 Core Load) 156 Watts
Intel Core 2 Duo E6750 (2 Core Load) 163 Watts
Intel Core 2 Duo E8400 (2 Core Load) 158 Watts
Intel Core 2 Duo E8500 (2 Core) 149W
Intel Core i5 750 (4 Core Load) 169 Watts
Intel Core i7 920 (8 Thread Load) 213 Watts
AMD Sempron 3600+ 148 Watts
AMD Athlon64 4000+ 172 Watts
AMD Athlon64 FX-60 (2 Core Load) 196 Watts
AMD Athlon64 X2 4800+ (2 Core Load) 173 Watts
AMD Athlon64 X2 5000+ (2 Core Load) 207 Watts
AMD Athlon64 FX-62 (2 Core Load) 235 Watts
AMD Athlon II X2 240e (2 Core Load) 153 Watts
AMD Athlon II X2 250 (2 Core Load) 163 Watts
AMD Athlon II X3 435 (3 Core Load) 183 Watts
AMD Athlon II X4 620 (4 Core Load) 195 Watts
AMD Athlon II X4 635 (4 Core Load) 211 Watts
AMD Athlon II X4 645 (1 Core Load) 139 Watts
AMD Athlon II X4 645 (2 Core Load) 158 Watts
AMD Athlon II X4 645 (3 Core Load) 177 Watts
AMD Athlon II X4 645 (4 Core Load) 193 Watts
AMD Phenom II X2 550 Black Edition (2 Core Load) 181 Watts
AMD Phenom II X2 555 Black Edition (2 Core Load) 187 Watts
AMD Phenom II X3 720 (3 Core Load) 213 Watts
AMD Phenom II X4 910e (4 Core Load) 176 Watts
AMD Phenom II X4 955 (4 Core Load) 236 Watts
AMD Phenom II X4 965 - 125W TDP
(4 Core Load)
243 Watts
AMD Phenom II X4 965 - 140W TDP
(4 Core Load)
264 Watts
AMD Phenom II X4 970 BE ( 4 Core Load) 214 Watts
AMD Phenom II X6 1075T (6 Core) 228 Watts
AMD Phenom II X6 1090T (6 Core) 263W

The power draw for the Athlon II X4 645 PC increases to 193 Watts with all four cores 100% stressed. Compared to the considerably faster Core i5 750 system (169W), the Athlon II X4 645 system demands a lot. AMD really needs to move its Athlon II processors to 32nm.

Next up, PCSTATS overclocks the Athlon II X4 645 chip towards 4GHz, then it's onto the processor benchmarks!

© 2014 PCSTATS.com Next Page >

 

Contents of Article: AMD Athlon II X4 645
 Pg 1.  — AMD Athlon II X4 645 3.1GHz Socket AM3 Quad-Core Processor Review
 Pg 2.  AMD Athlon II X4 645 CPU Overclocking Report
 Pg 3.  CPU System Benchmarks: Sysmark 2007
 Pg 4.  CPU System Benchmarks: PCMark Vantage
 Pg 5.  CPU Synthetic Benchmarks: SiSoft Sandra Processor
 Pg 6.  CPU Synthetic Benchmarks: SiSoft Sandra Memory
 Pg 7.  CPU Calculation Benchmarks: Super Pi
 Pg 8.  CPU Calculation Benchmarks: wPrime2.0
 Pg 9.  CPU Calculation Benchmarks: ScienceMark2.3, WinRAR
 Pg 10.  CPU Rendering Benchmarks: Cinebench R10, Bibble 5
 Pg 11.  CPU Rendering Benchmarks: POV-Ray 3.7
 Pg 12.  CPU Rendering Benchmarks: SPECviewPerf 10
 Pg 13.  CPU Synthetic Gaming Benchmarks: 3DMark Vantage, 3DMark 06
 Pg 14.  CPU Gaming Benchmarks: Crysis, FEAR
 Pg 15.  Incremental Clock Boost, Minor Gain?

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