Breaking the 100mhz bus Barrier
Kelly Spang
Waltham, Mass. -- While chip makers hype ever-increasing CPU speeds,
VARs actually expect bigger performance leaps from a faster system
bus, as the industry moves to a 100MHz bus design.
Intel Corp., Santa Clara, Calif., will be first in the channel
supporting the faster bus. However, rivals-such as Advanced Micro
Devices Inc. and National Semiconductor Corp.-will likely reap more
of the performance benefits, at least in the short term, industry
observers said.
Components and systems supporting the 100MHz platform will be
available from Intel by April. Systems from some of Intel's rivals
will be available this summer.
Overall, the transition from a 66MHz system bus to 100MHz will
nearly double the bandwidth between the processor and system
components, including main memory and Level 2 (L2) cache.
Chip makers can "pump up the megahertz of the microprocessors, but
to improve the overall [system performance] we need to increase the
[system] bus from 66MHz to 100MHz," said Jamal Haider, director of
marketing at Centaur Technology Inc., a subsidiary of Integrated
Device Technology Inc. (IDT), a Santa Clara, Calif.-based chip
maker.
In overall system performance, VARs can expect a 10 percent or
greater increase with the move to the 100MHz bus, OEMs and component
suppliers said.
A key performance difference between Slot 1, Intel's Pentium II
architecture, and Socket 7, the design used by several rivals, lies
in the fact that Slot 1 more closely knits the packaging of the
processor and the L2 cache.
The impact of moving to the 100MHz system bus could serve as "an
equalizer" between Socket 7 and Slot 1 designs, said John Howland,
owner of Specialty Tech, a VAR in Lake Forest, Calif.
"By going to 100MHz, [Socket 7] will make up a lot of that
[performance difference]," he said.
Nathan Brookwood, microprocessor analyst at Dataquest Inc., San
Jose, Calif., agreed.
"The introduction of [the 100MHz system bus] should benefit Socket 7
more than Slot 1 because with Slot 1 the access to [L2] cache has
never been constrained by the bus," Brookwood said.
While the L2 cache sits on the motherboard with the Socket 7 design,
running at 66MHz, Intel incorporates its L2 cache into the Single
Edge Contact cartridge housing the CPU. As a result, L2 cache for
Slot 1 processors run at half the speed of the processor.
"One of the reasons we're very excited to push the Super 7 platform
with the 100MHz is because it is going to mean a lot more for us
than it's going to mean for the Slot 1 infrastructure," said Michael
Steele, AMD K6-3D product manager.
In the third week of April, Intel plans to deliver its Slot 1 350MHz
and 400MHz processors and its 440BX chipset to support the 100MHz
for Pentium II. Volume pricing on the new processors is expected to
be approximately $650 for the 350MHz and around $850 for the 400MHz.
Intel executives said Slot 1 will reach 350MHz, 400MHz and 450MHz by
the end of the year but would not comment on pricing or delivery.
While Cyrix Corp., a subsidiary of National Semiconductor based in
Richardson, Texas, declined to comment, AMD, Sunnyvale, Calif., said
it expects to unveil its 300MHz K6-3D, the first of its processors
to support the 100MHz system bus.
IDT expects to ship a 240MHz and 266MHz version of WinChip C6+ by
summer, Haider said.
Socket 7 systems based on the 100MHz design will carry a 10 percent
to 15 percent premium, said chip makers. For Pentium II systems, the
100MHz bus could add as much as $300 to $500 to the Slot 1 price
tag, component makers said.
Copyright (c) 1998 CMP Media Inc. |
