A booted architecture
In terms of performances, K10 architecture improves upon K8 in various domains in addition to the increase from 2 to 4 cores. In the processing of SSE, the IPC has been boosted via the integration of two SSE 128 bit processing units which in theory will allow it to attain speeds twice as fast as the K8 and be equivalent to a Core 2. Caches were adapted to these new capabilities and their speeds were doubled to identical frequencies.
The branching predictor unit was improved in order to be able to process indirect branches, while the DDR2 and DDR3 memory controller (on the AM2 and AM3) gained increased buffers, an improvement of prefetch and can work in ganged (1x128 bits) or unganged mode (2x64 bits, which can, for example, enable simultaneous reading and writing).
AMD also included improvements in terms of whole number division speed compared to the K8 (for example, IDIV r32 goes from 40 to 22 cycles) and memory reading instructions are now managed "out of order". Finally, there is a unit devoted to stack management.
As for power use, on the AM2+ platform a Phenom separately controls the power of each core and memory controller allowing finer energy management. In addition, the frequency of the 4 cores can be set independently however power levels remain identical and equivalent to that which is required by the core that is most in use. We were able to confirm this desynchronisation of cores in tests via adjusting their coefficient via AMD Overdrive software.
2.3 GHz to start with
To start with, AMD launches two Phenoms, the 9600 and 9500. Set at 2.3 and 2.2 GHz, respectively, they were announced at around $283 and $251 or 240 € and 215 €. As you can see, AMD is aggressive on prices and Intel simply does not offer a Quad core in the 9500’s price range (the Q6600 being at around 240 €). Of course, beyond prices there is the question of performance, something we will look at further on in this article.
While we are on the subject, it’s unfortunate that AMD hasn’t managed to go beyond 2.3 GHz. Up until a week ago, a 2.4 GHz model, the Phenom 9700, was also to be launched at the same time. At the release event for European tech journalists, AMD had even organized the possibility to benchmark this CPU in a controlled environment (impossible to install any other benchmarks other than those present, amongst other things). Unfortunately, this version didn’t prove to be too stable and AMD justifiably decided to not launch it for the moment. It goes without saying that the relatively weak increase in frequency could be problematic if not resolved rapidly especially given AMD’s intent on attaining 2.6 GHz in the first quarter of 2008.
The Spider platform
AMD took advantage of the release of the Phenom to launch not just a processor but a complete platform called the Spider. It is composed of three elements:
- An AMD Phenom processor
- An AMD 790FX chipset motherboard
- A Radeon 38x0 GPU graphic card
While Intel already tried imposing its Centrino platform concept on the desktop via ViiV, AMD is better equipped to do so given that their acquisition of ATI gives them an entire foundation for a PC desktop destined for games. At the moment, Intel is in fact absent from the GPU market while NVIDIA isn't currently offering any CPUs.
The 790FX sets itself apart with expanded PCI-Express management as it can control 4 PCI Express x16 ports, two being cabled with 16 PCI-E lanes and with 8 lanes. CrossFire X, which will allow running 3 or even 4 graphic cards at the same time (did someone say Crysis ?), will need a motherboard of this type, but it will not arrive before the end of 2008. On the other hand, the southbridge is rather standard with the number of SATA being limited to 4 and network management has to be confined to additional chips.
As for the GPU, a short while ago we published a
complete test of the Radeon 38x0 if you want to brush up on the details.
In order to underline that it wasn’t just a processor that was launched but rather an entire platform, we obtained a complete « Spider » configuration that will be on sale starting Monday. Of course, for our test we only used the motherboard and processor in order to be able to integrate everything to our CPU test protocol.
