"I come from the world of software, and we need to talk," said Herb Sutter, a software architect with Microsoft, in his opening remarks to a hardware-heavy audience today at In-Stat/MDR's Fall Processor Forum here.
The software development community recognizes that processor makers have been forced to adopt multicore designs in order to deal with the heat problems caused by fast chips, Sutter said, but the community isn't sure that hardware designers understand just how much work they've created for the software industry.
"The free lunch is over," Sutter said. For a long time now, PC software performance has improved as PC processors from Intel and Advanced Micro Devices ran faster and faster. Developers could make minor changes to existing software programs and watch their performance increase as the hardware engineers figured out ways to improve processor performance, he said.
But multicore designs five of which were showcased by their creators here today, are forcing the client software world to deal with concurrency--the ability to break a single task into multiple parts that can be processed separately and reassembled later--Sutter said.
Developers who create applications for servers have already cleared this hurdle, since multicore processors and multiple-processor systems have been common in the server market for several years, Sutter said. Many of these apps were designed with multiple software threads to take advantage of the parallelism of these systems, he said. Client application developers, however, have been stuck for years in a single-thread world, creating what Sutter called "sequential applications."
As a result, software developers need to come up with new ways of creating software, Sutter said. Just as the rise of object-oriented programming added a layer of complexity to assembly languages, concurrent programming requires a new level of abstraction.
Microsoft is working on this problem through the Concur Project, an internal development group headed by Sutter that seeks to define those abstractions and tie them to hardware to "re-enable the free lunch," he said. But all software developers must recognize that, going forward, PC software needs to be developed with concurrency in mind, he said.
Chip designers can help by remembering the software developer as they create their products, Sutter said. "Hardware should focus on programmability first, speed second. Don't assume that us OS guys and compiler guys and...the end application developer guys will just figure this out," he said.