Intel Defends Front Side Bus

SAN FRANCISCO — If there were any doubt that AMD has Intel’s attention, it was dashed in a technical session at the Intel Developers Conference here today.

AMD, which uses a direct connect architecture, regularly harps on Intel’s use of the front side bus in its processors.

Steve Pawlowski, an Intel veteran of some 24 years and one of the original designers of the front side bus,
took a moment to defend Intel’s decision to stick with the design during his overview of the company’s multi-core plans.

“It was a simple bus we expected to be around for a few generations,”
said Pawlowski. “But its ability to scale has been a great benefit. We
[understand] how the bus works and it’s easy to manage.”

Pawlowski said the benefits of switching to a direct-connect architecture
are largely outweighed by many other technologies Intel employs, including
caching.

“Memory on the processor looks very good, but if you double the
cache size, and we have really good cache technology, you can dramatically
increase the frequency of the bus.

“We’re still not getting completely out of
the way of the processor, but overall we have a lot of leg room [to improve
performance].”

Intel is spending a lot of time at IDF providing details of its Core Microarchitecture technology, the design for desktop, mobile
and servers due out later this year.

One element of Core is what Intel calls
a smart shared memory cache that either core in a dual- or multi-processor
system can use.

“It’s a dramatic improvement because you don’t have to go
multiple times to the bus; it’s a higher efficiency cache,” said Ofri
Wechsler, and Intel Fellow and director of its mobility microprocessor
architecture.

“I think what Intel’s saying is the cost of switching out to a direct
connect architecture wouldn’t bear out as a benefit to the customer,”
Charles King, principal analyst with Pund-IT Research, told
internetnews.com.

“But AMD’s on-chip memory communication seems to
have been a real differentiation point for them and the proof is they’ve
doubled their market share in X86 servers the past year. I expect Intel to
catch up [with AMD’s technology], but we’ll have to see this summer if they
can surpass them. AMD’s not sitting still.”

Intel’s Core Microarchitecure is based on work done at Intel’s research
facility in Israel that initially focused on mobile platforms. With the
increasing interest and demand for systems that consume less power, Intel saw
an opportunity to leverage the same energy-efficient technologies for mobile
to other platforms.

“Cranking the frequency isn’t an option because you pay too dearly on
power [requirements],” said Wechsler. “Power [savings] is now the most
important item for us in design.”