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
|AMD Athlon II X4 630
|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|
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.
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.