Virginia Tech talks up the G5

Macworld - Link 1,100 Power Mac G5s together and it will make the news. Link 1,100 Power Mac G5s together to create the third most powerful academic computing facility in the world, and it will make headlines worldwide and earn project director Dr. Srindhi Varadarajan adulation from Macintosh enthusiasts.

To close the first night of the O'Reilly Mac OS X Conference, Varadarajan gave a presentation on how his team settled on the G5 for their system and what they had to do to get it running. To begin, Varadarajan told the audience why they wanted to build a Terascale Computing Facility at Virginia Tech.

"To use one of the Department of Energy computers, you have to write a grant to get time," Varadarajan said. "You use it, usually in about a month, and then you have to start again, essentially retarding the process of research."

Since Virginia Tech has a world-class computational sciences and engineering program, Varadarajan said that he wanted to build world-class computational facilities to compliment that program. The problem is that, while he wanted a world-class system, academia generally doesn't have a budget to match. So, Varadarajan envisioned a system based on off-the-shelf processors bound together with an extremely fast off-the-shelf backbone.

To build the system, Varadarajan said that he and his team began by working with Dell to supply 64-bit Intel Itanium 2 processors. The key for Varadarajan was price versus performance. After going back and forth with Dell, Varadarajan said that the negotiations fell through. He then evaluated 64-bit processors from Advanced Micro Devices Inc. (AMD), IBM Corp. and Hewlett-Packard Co. (HP). But IBM said that the PowerPC 970 would be months away, and AMD and HP gave Varadarajan quotes in the $9 million to $11 million range, well over his budget. Before Apple announced the G5, Varadarajan was in a tough spot.

On June 23, Apple unveiled the G5. Varadarajan said he contacted Apple on June 26 about the possibility of using the G5 for the Terascale Computing Facility. While talking with Apple, representatives from the company asked Varadarajan how long he had been a Mac user.

"I had to tell them I'd never used the Mac," Varadarajan said. "I'm probably one of the few people who came to the platform by reading the kernel manual."

Nevertheless, the G5 had exactly what Varadarajan was looking for. In addition to being a 64-bit processor, the PowerPC 970 processor has two floating point units allowing the processor to complete two double precision floating point calculations per clock cycle.