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Review: AMD Athlon II X4 620 and 630: introducing the budget quad-core CPUs

by Tarinder Sandhu on 16 September 2009, 05:00 4.1

Tags: Athlon II X4 620, AMD (NYSE:AMD)

Quick Link: HEXUS.net/qatyg

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Where do these new quad-core chip fit in?

Processors Cores Architecture Process Form factor Clock speed L2 cache (total) L3 cache Memory-controller speed (up to) Voltage TDP etailer pricing
AMD Phenom II X4 965 Black Edition 4 K10 45nm AM3 3.4GHz 2MB 6MB 2.0GHz 0.875-1.5V 125W £175
AMD Phenom II X4 955 Black Edition 4 K10 45nm AM3 3.2GHz 2MB 6MB 2.0GHz 0.875-1.5V 125W £145
AMD Phenom II X4 910 4 K10 45nm AM3 2.6GHz 2MB 6MB 2.0GHz 0.875-1.5V 125W £120
AMD Athlon II X4 620
4 K10 45nm AM3 2.6GHz 2MB N/A 2.0GHz 0.90-1.425V 95W £75
AMD Athlon II X4 630
4
K10
45nm
AM3
2.8GHz
2MB
N/A
2.0GHz
0.925-1.425V
95W
£95











AMD Phenom II X3 720 Black Edition 3 K10 45nm AM3 2.6GHz 1.5MB 6MB 2.0GHz 0.875-1.425V 95W £90











AMD Phenom X2 550 Black Edition 2 K10 45nm AM3 3.1GHz 1MB 6MB 2.0GHz 0.85-1.42V 80W £75
AMD Athlon X2 7850 Black Edition  2 K10 65nm AM2+ 2.8GHz 1MB 2MB 1.8GHz 1.2-1.25V 95W £46
AMD Athlon II X2 250  2 K10 45nm AM3 3.0GHz 2MB N/A 2.0GHz 0.85-1.42V 65W £55
AMD Athlon X2 6400+ BE 2 K8 65nm AM2 3.2GHz 2MB N/A 1GHz 1.35-1.4V 125W N/A
AMD Athlon X2 6000+ 2 K8 65nm AM2 3.1GHz 1MB N/A 1GHz 1.1-1.4V 89W N/A

Analysis

We've listed various AMD processors segregated in terms of number of cores. Take a look at the Phenom II X4 910, operating at 2.6GHz and equipped with the full complement of 2MB of L2 cache and 6MB of L3 cache. The cache arrangement is the same on all Phenom II X4s, and models are differentiated by clock-speed above all else.

The chopping machine cometh

The method that AMD is using to launch the cheapest-ever quad-core CPU is to harness the 45nm AM3 'Deneb' architecture but decrease costs by lopping-off the die-increasing 6MB of L3 cache. The removal of the cache also results in a lower TDP - 95W from 125W - yet all other Phenom II X4 features are kept intact. In effect, then, the Athlon II X4 620, codenamed Propus, is a Phenom II X4 910 but without the 6MB of L3 cache.


Athlon II X4 620 die-shot, courtesy of AMD

Cacheless in Dresden

See, no mass of L3 cache that dominates the bottom half of the Deneb core. As a consequence, reducing the die-size from the Phenom II X4's 258mm² to 169mm² enables AMD and its partners to etail the '620 chip at $99 (£75, including VAT, we hope), thus making it the cheapest quad-core CPU available. Transistor count drops from Deneb's 758m to 'just' 300m for Propus.

Bolstering the nascent cacheless quad-core range is the higher-clocked Athlon II X4 630, operating at 2.8GHz and likely to etail at £95 ($122) or so. Got this far and still wondering why they're called Athlon and not Phenom? It's all to do with the cache, or lack thereof: Athlon chips don't feature any L3.

Putting it together

Clearly, AMD's aim is to facilitate system builders and enthusiasts into specifying low-cost PCs with quad-core CPU processing. It makes implicit sense for either Athlon II X4 chip to be paired with the 785G chipset, released in August 2009 and toting DX10.1 integrated graphics and either DDR2 or DDR3 compatibility.

As a pair, then, Athlon II X4 620 and a decent 785G should cost less than £150.

Multi-pronged competition

The vagaries of current CPU architecture - cores, caches, clock-speed, etc - mean that the same £75-£100 can be spent on dual-, triple, or quad-core chips. AMD's own dual-core Phenom X2 550 comes in at around the same price, as does the triple-core Phenom II X3 720.

Looking farther afield, to the blue team, Intel currently lists a trio of 7-series dual-core chips - Core 2 Duo E7400, E7500, E7600 -  which etail under £100. The faster 8-series models start at £120, but jumping straight up to quad-core, the £100 Core 2 Quad Q8200 (95W) is the obvious cores-to-cores competitor for the X4 620 and 630.

* update 16/09/09. AMD has informed HEXUS that a number of Athlon II X4 620 and 630 chips will use the existing Deneb architecture but with the L3 cache disabled. For all intents and purposes, the Deneb and Propus chips will appear as identical models to the system.