IT'S ALL BECOMING A PLAY STATION |
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(THE 'SWINGS AND SLIDES' IN THE PLAYSTATION 3) |
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The latest ‘play toy’ from Sony is the new Playstation 3 (aka PS3). It is not enough to just call it a game console, a lot of reviews about it has considered it as a ‘multi-function’ entertainment system (Microsoft MSN), some has even gone to the extent of describing it as a form of super computer (The EE Times UK, talking about a statement made by Andrew Rassweiler) . |
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The main processing unit and perhaps the most complicated part of the PS3 is its main processing unit. It is known as the Cell broadband engine, designed jointly by Sony (yes, you read it right), Toshiba and IBM (the alliance was called ‘STI’, formed in 2000). The Cell processor has over 234 million transistors onto a single die manufactured on a 90nm silicon-on-insulator process. The cell has nine processing cores. So imagine nine processors working together on one chip, this is extending the current trend of multi-core processing.
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The picture above is taken from the IBM site (Cell Broadband Architecture). It shows a brief overview of all the processors working together on one chip. Its shows the SPEs interconnected by the Element interconnect Bus (EIB). One can also notice that they all operate on a common memory space even though the both the PPE and the SPEs have different functions. The PowerPC PPE (64-bit power architecture) is a very powerful processor. Although it is powerful enough to run on its own, or even run a computer (How stuff works: “Playstation 3 cell processor”) it acts as a controller/manager to the SPEs, thereby making the Cell flexible enough to support various operating systems. The PPE consists of a processing unit connected to a 512KiB level 2 cache. Every task that needs to be done goes through the core, which in turn assigns the different tasks to each of the SPEs, taking into consideration the need to achieve the maximum level of performance from the processor. There are eight SPEs (running at 3.2GHz) in the cell, each of them a 128 x 128-bit vector processor. However, only seven of them are used, the other one is used as a spare, and its disabled to improve production yields. It only comes into use if one of the other SPEs stops working or in the case of wear and tear. However, only 6 from the remaining seven are used for intense tasks, the seventh one is to deal with aspects of the operating system and security. From the diagram above, it is easy to see that each of the SPEs are capable of working independent of each other, or they can work in collaboration as well, if need be; this gives the cell the advantage of being able to multitask as well. The SPE contains 256KB of non cached memory for local storage (LS in the diagram above), which means that for every instruction the SPE executes, it is directly placed there by the programmer, which might however mean that rather than the whole complexity of the system being placed on the processor, it is entirely up to the programmer; thereby there really can’t be any room for mistakes from the programmer whatsoever, although this process seems to be faster than having a general cache (Dailytech: The Playstation 3 dissected). However, I am a little surprised as to why the SPE needs to be non-cached in the first place, there is always bound to be human errors, so I personally think leaving the processor to handle the complexity of the system would have been a better idea, since the cell itself was built for complex processing (I guess it leaves room for future developments??) The Element Interconnect Bus (EIB) connects all the other elements together in a ring-style bus. Although the EIB does not actually deal with any sort of processing itself, but since it connects the different elements in the cell together, it has to deal with the constant data flow going through it to different destinations in the system. |
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Brief overview of the Graphics The GPU (Graphics processing unit) that was created for the PS3 is the RSX (Reality Synthesizer). Personally, I can say this happens to be one of the most interesting parts of the PS3, as it is what you see on the screen, and probably what most gamers would enjoy more. This is the part of the system that makes you feel like you are actually present ‘live’ in a game whilst playing a particular a game. The RSX was manufactured by Nvidia.
The RSX is a 550MHz graphics chip, with over 300 million transistors in total (that is more than there is on the main processing unit of the PS3). It has independent pixel/vertex shader architecture, making it a very high level of graphics. |
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The PS3 has finally been launched here in the UK (almost 4 months after the rest of the world got the unit). However, only the 60GB one has been released here in the UK so far, which obviously means we only have the expensive one available to us, and from price comparisons, it seems Europe is paying the most money for the PS3 ( a reason I am still trying to understand). |
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References
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