As I wrote above, the described notebook is unique as it incorporates not two but three processors. Besides the traditional CPU and GPU, the Qosmio F50-10K is equipped with a Quad Core HD processor. I have not seen this chip before in desktop or mobile computers. The processor is Toshiba’s own innovation and incorporates technologies found in the Cell processor which is, by the way, developed by a joint venture of Toshiba, Sony and IBM.
The Quad Core HD chip is also known as SpursEngine, and Toshiba is promoting its use in computers as well as consumer electronics. Without delving deep into details, I can tell you that the SpursEngine is a special-purpose coprocessor intended for real-time processing of video (including high-definition video). Especially interesting is that the SpursEngine uses Synergistic Processing Elements, borrowed from the Cell micro-architecture, as main computing components. Thus, SpursEngine is just one more application of the Cell micro-architecture which has been mostly limited to same-name processors installed into the popular game console Sony PlayStation 3.
To remind you, the classic Cell processor consists of eights SPEs and a Power Processor Element (PPE) that serves as a coordination center. These components are all joined together with a ring bus. This design allows using Cells as general-purpose processors not only in gaming consoles but even in special-purpose servers. However, the SpursEngine is not a full-featured processor, even though it uses the same micro-architecture. It is an additional coprocessor that cannot solve any tasks without being controlled by the main CPU. In other words, the SpursEngine chip lacks a PPE. It only incorporates four SPEs and a few auxiliary subunits.
The SPEs are in fact miniature RISC processors with 128-bit SIMD architecture. Each SPE can perform operations with sixteen 8-bit, eight 16-bit or four 32-bit integers or with four single-precision real numbers per one clock cycle. Besides 128-bit registers for storing operands and data, each SPE has a dedicated 256 kilobytes of SRAM. Theoretically, the SpursEngine offers excellent capabilities for processing of large arrays of data in parallel. Processing video is an example of such a task, so Toshiba suggests that the SpursEngine be used for it in the first place.
Targeting this application, Toshiba endowed the SpursEngine with hardware video codecs of H.264 and MPEG-2 formats. Thus, the SpursEngine is an ideal device for analyzing and applying various effects to the video stream being played or exported in real time. It means the SpursEngine can be used in a wide range of devices, not only computers (computers don’t actually need much help in this area because they have advanced multi-core CPUs and high-performance GPUs that can process video with their own shader processors).
Anyway, even though Toshiba has announced a number of home appliances with SpursEngine, this technology began to be promoted in PCs. The integration into the existing Centrino 2 platform made it necessary to equip the SpursEngine with additional interfaces. Particularly, this coprocessor supports a PCI Express x4 bus to connect to the system chipset and has an XIO interface for 64 or 128 megabytes of dedicated XDR DRAM (developed by Rambus). This is how the SpursEngine or Quad Core HD processor is implemented in the discussed notebook.
The SpursEngine SE1000 is clocked at a frequency of 1.5GHz, which is only half the frequency of the original Cell processor. However, the developer tried to reduce the chip’s heat dissipation keeping in mind its applications in consumer electronics. Therefore the clock rate is not set too high. The SpursEngine has a peak performance of 48 gigaflops anyway, easily copying with tasks intended for it, while its heat dissipation is only about 10-20W.
Besides Toshiba’s Qosmio F50, G50 and G55 series notebooks, the SpursEngine can be found on standalone PCI Express cards offered by Leadtek and Thompson as well as in the new 42- and 46-inch TV-sets Toshiba Regza.