AMD unveils Phenom CPU and ‘Spider’ platform

Posted at: 12:52pm 19th November 2007 by Ben Hardwidge

Four cores plus four graphics cards CrossFire equals eight legs of a spider. You’ll need a Phenom CPU, a Radeon HD 3800-series graphics card and an AMD 790 motherboard chipset

Spiders have loaned their names to everything from Google bots to the drummer in Bad News. As well as affording you the opportunity to make references to webs, naming something after man’s most famously feared arachnid also allows references to groups of ‘eight’ in a slightly more credible way than an octopus might. It’s the latter that AMD’s betting on with its new ‘Spider’ platform, combining four CPU cores with four Radeon HD 3800-series graphics cards.

The CPU

Let’s start with the quad-core CPU, which AMD has now officially launched today. Called the Phenom, it’s based on AMD’s 65nm Barcelona core, which differs from Intel’s quad-core Core 2 CPUs in that all four cores are on a single die, as opposed to being two dual-core CPUs stuck together. As such, the Phenom also has a more comprehensive approach to cache, with each core having its own set of Level 2 cache, as well as a single shared pool of Level 3 cache.

By comparison, Intel’s quad-core chips have two pools of Level 2 cache, because they’re basically two Core 2 Duo chips sandwiched together. So, if Core 0 wants to communicate with Core 2, then the data has to travel via the front side bus, and then back to the CPU again. AMD argues that this creates latency, and clogs up the front side bus bandwidth, which is unnecessary. As well as this, the Level 2 cache system gives each core its own space in which to store data, and it can always move that data down to the Level 3 cache if it needs to be retrieved by another core. There’s no chance of one core taking up most of the cache and starving its neighbour of resources, and less danger that one core can overwrite data that’s been carefully cached by the other.

Three models have been launched today. The first is the Phenom 9700, which is clocked at 2.4GHz, has a TDP of 125W, and has 2MB of Level 3 cache, with 512KB of Level 2 cache for each core. Below this is the Phenom 9600, which is clocked at 2.3GHz and has a TDP of 95W, while the 9500 is clocked at 2.2GHz and has an identical TDP to the 9600. All three CPUs feature Hyper Transport 3, and have a memory controller that can handle 1,066MHz DDR2 RAM.

AMD claims to have improved the floating point performance of Phenom CPUs over their Athlon 64 predecessors by adding 128-bit floating point units, and says that it’s also improved the branch prediction for Visual Basic, C++ and Java applications. AMD hasn’t announced exact UK pricing yet, but the company told Custom PC that the Phenom 9700 would be priced similarly to Intel’s Core 2 Quad 6600.