AMD recently launched FX-Series processors based on the Bulldozer architecture haven't managed to deliver the performance everybody expected them to, and an ex-AMD engineer has recently come out to share its vision regarding the Bulldozer performance issues.
Cliff A. Maier has worked as a member of AMD's technical staff until a few years ago, when it left the company at about the same time as AMD has started to use automated design tools for its chips.
According to the engineer, the fact that Bulldozer arrived later than everybody expected it has little to do with its performance problems, as the main issue that affected the architecture was the chip makers adoption of automated design techniques.
Compared to the traditional design techniques that rely on hand-crafting performance-critical parts of the processor, automated tools speed up the design process, but cannot ensure maximum performance and efficiency.
"The management decided there should be such cross-engineering [between AMD and ATI teams within the company] ,which meant we had to stop hand-crafting our CPU designs and switch to an SoC design style,” said Maier in a forum post on Insideris.com.
“This results in giving up a lot of performance, chip area, and efficiency. The reason DEC Alphas were always much faster than anything else is they designed each transistor by hand. Intel and AMD had always done so at least for the critical parts of the chip.
“That changed before I left - they started to rely on synthesis tools, automatic place and route tools, etc.," continued the engineer.
According to Maier, automatically-generated designs can be 20% bigger and slower that hand-crafted silicon, leading to an increased transistor count, increased die space and low energy-efficieny.
"I had been in charge of our design flow in the years before I left, and I had tested these tools by asking the companies who sold them to design blocks (adders, multipliers, etc.) using their tools. I let them take as long as they wanted.
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