Original URL: http://www.theregister.co.uk/2003/07/10/intels_tanglewood_pumped_full/

Intel's Tanglewood pumped full of DEC Alpha goodness

Bannon's dream lives on

By Ashlee Vance

Posted in Servers, 10th July 2003 21:32 GMT

Intel's recent hiring of Alpha guru Peter Bannon has helped provide a clearer picture as to what the Tanglewood processor will look like.

A old Compaq presentation (.PPT) authored by Bannon gives a nice indication of where Tanglewood's future may lie. Bannon, after all, is Mr. Tanlgewood so his interests in integrated memory controllers, integrated networking and support for multithreaded software have alarms starting to sound.

The Register was the first to report on Compaq's Tanglewood work. The chip appears to have been a follow on the to EV8, which was killed when Compaq sold its Alpha IP and engineers to Intel. Bannon was intimately involved with the EV8 and later designs and is carrying that work to Intel's version of Tanglewood.

With the EV8, Bannon integrated a Rambus memory controller in Alpha as a way of improving bandwidth and lowering latency. It's doubtful that Rambus will make it onto Intel's roadmap, but Intel execs indicate some type of integrated memory controller is on its way.

"We obviously have looked at it and haven't done it yet, because the memory technology evolves faster than the micro core - and when you get out of synch, that is a problem," Intel's Mike 'The Fist' Fister told CNET. "And I think that somebody in the industry will figure out that that is a problem - somebody who has already done it."

So you are slagging off AMD's use of an integrated memory controller in Opteron right, Mike?

No.

"We haven't said whether we would or wouldn't do it, but it is a natural thing to think about. Just like putting cache on a die is something we said we would do - or multi-core integration," he continued.

Just to be clear: only an insane vendor would go the integrated memory controller route, but Intel is considering it. OK, thanks, Mike.

While The Fist may seem a tad confused on the issue, Bannon and his old Alpha chums working on Tanglewood are not. Unlike the hulking Itanics currently on Intel's roadmap, Tanglewood is designed to be an elegant multicore chip that gives all of the processor cores ample access to memory and that can handle multithreaded software well. Using an integrated memory controller would be a nice way to pull off these goals.

"The integrated memory controller is obviously closer to the CPU, so latency tends to be lower," said Gordon Haff, an analyst at Illuminata. "In a multicore design, it also lets all the cores share the memory controller which adds another incremental benefit."

Haff noted that memory controllers are usually left off the chip to make room for more cache and core logic. With Tanglewood, however, Intel is moving away from its cache crushing chips and toward a more throughput oriented design.

Along with the memory controller, Bannon's attention has been focused on adding multithreading support to high end chips, speeding up processor to processor communication and integrated networking.

It's safe to assume that most if not all of these technologies will appear in Tanglewood.

The old Alpha team is pulling its weight over at Intel. One has to wonder what happened to the Intel folks behind the first Itanic design. They messed up so badly that HP took McKinley into its own hands.

Most insiders say Intel did the grunt work on Madison, but high-end chip-making does not appear to be Chipzilla's forte.

It's lucky Mr. Tanglewood is around. ®

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