Thursday, November 26, 2009

End of the Cell Broadband Engine?!

Yesterday the InternetNews.com released a piece of news about the end of the Cell Broadband Engine. David Turek the VP of deep computing at IBM said during an interview with the German site Heise Online that the power XCell-8i will be the last of the Cell line. IBM will be focusing on power7 processor, which is due mid 2010.

In this news article, it is mentioned, by Jon Peddie, that Cell processor had many shortcomings that became apparent, such as lack of direct access to the global memory by its computing engines (the SPEs) and wrongly mentioned that everything has to go through its powerPC core, which creates a bottleneck. This is technically not true. The PowerPC core is not handling any of the requests initiated by the other compute engines (the SPEs). Also, it might be noted by some researchers that its cache should be bigger, but its performance still noted by many to be the best compared to other multi-core processors fall within its category. In addition, the Cell processor taught a lot of developers and researchers the best parallel programming practices for multi-core processors. The fact that everything is controlled by the developer forced all its programmers to think better of the best ways to optimize their algorithm's execution time.

Although I may somehow believe that IBM may do changes to the Cell processor. It is very difficult to believe that IBM will end its Cell processor line that soon. IBM invested a lot of money and time and also many of its customers invested tons of money adopting the Cell processor.

I think IBM is trying to produce its own line away from Sony and Toshiba without giving away $500 million worth of investment and five years of engineering. It is about business. The cell processor is one of the master pieces in the multi-core processors. And as mentioned by David Turk the future is for hybrid multi-core processors, for a very simple reason: they provide great ratio of processing speed to consumed power.

I think IBM will reuse the SPEs instruction set along with their traditional PowerPC architecture but the change might be in how the cache will be organized and managed. Also, I think IBM is rethinking the cores interconnect network. They may use either dynamic networks or a mix between on-chip-network and shared cache architecture.