AMD Phenom II: Competition is Back!

Here comes another processor from AMD's stable, which has heated up the battle for supremacy in the Quad core CPU space

Sunday, February 01, 2009

When AMD first launched the Phenom line of processors a couple of years ago, it couldn't manage to gain too much attention. It was re-launched the following year in 2008 with a slightly better reception, but not enough to make people switch from Intel. Now, Phenom II is the latest addition in the family and an updated brand name for AMD's 45nm multicore central processing units.

Previous desktop class processors from AMD were manufactured on a 65nm process while Intel was out with their 45nm ones. But this time, alongside a new CPU with smaller transistor elements, this release introduces some brand-new technology. With it's launch, the new processor also gives birth to a new platform which is gaining attention rapidly in the world of enthusiasts for its overclocking capabilities.

The new platform is called the Dragon and it consists of the Phenom II and the latest Radeon HD 4800-series graphics cards. We got the X4 940 Processor for review. Let's now have a look at some of the features that these new AMD engines boast of.

Higher clock rates
As the die shrinks, the voltage needed to drive Phenom II is down significantly. The new smaller size in combination with an improved micro-architecture gave AMD a chance to increase the clock rates. Whereas the first-generation Phenoms topped out at 2.6 GHz, the latest Phenom IIs starts at 2.8 and goes as high as up to 3.0 GHz.

6 MB of L3 cache
It just wasn't an option for AMD simply to arm the first-generation Phenom with a larger L3 cache. The power requirements of those 65 nm transistors would have undoubtedly boosted consumption past the 140 W mark. But current draw was sufficiently reduced in switching to 45 nm technology to enable AMD to augment the L3 cache size from 2 MB to 6 MB. In any case, the separate 512 KB caches provided for each individual core did not change with this redesign, nor did the 64 KB L1 instruction and data cache areas.

Cold bug removed
The 'Cold Bug' as it is known is a physical phenomenon which causes the processors to cease functioning below a certain temperature. As weird as it may sound, the problem is serious for extreme overclockers. The bug prevents the use of extreme cooling methods such as Liquid Nitrogen or Dry Ice. With the elimination of the bug, the CPUs are expected to give overclocking a whole new definition.

Compatible and cost efficient
AMD has always taken great pains to stress their backward compatibility as a selling point. For a consumer, upgrading the processor should not always mean buying a new motherboard and RAM. Now true to it's promises, AMDs new line of processors are compatible with earlier AM2 as well as the AM2+ sockets. Motherboard vendors have already published compatibility lists, and using them to provide information about which of their motherboards will work with the Phenom II,

Power management: A better Cool'n'Quiet
Due to performance drops when Cool'n'Quite was enabled, the feature was not used much often. The new Phenom ll introduces a better Cool'n'Quiet. If one specific core needs to work on full frequency, CPU doesn't allow independent change of frequency of other cores. Then all 4 cores are operating at full speed (frequency). With Cool'n'Quiet enabled performance drop is minimal and is much lower than on a 65nm Phenom.

The benefit
Though the Intel Core i7 965 is the fastest processor available in the market, it is also insanely expensive. The Phenom ll has been competitively priced near the Intel's Core 2 Quad range of processors but has a better performance. Though the price of the Phenom ll X4 940 and the cheapest of the Core i7 family have a similar price, the Phenom has an advantage. Core i7 can only work with a new motherboard, one which has the X58 chipset. Plus it only supports the triple channel DDR3 memory which is still quite expensive as compared to the affordable DDR2 which the Phenom lls use.The Phenom ll 940 enjoys a performance level in between the Core 2 Quad and the Core i7 at an affordable price. At least till the time Intel cuts prices and DDR3 memory is cheaper.