Intel Redesigns P2 Case For Higher Speeds

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August 14, 1998 (4:28 PM EDT)

By Andy Patrizio,

Intel will begin shipping Pentium II CPUs with a new casing designed to improve signal transmission and cooling, letting Intel crank up the speed of the chips well beyond the 500-MHz mark.

Intel will begin using this new housing for the chips in the fourth quarter of this year on Pentium II chips running at 350 MHz or higher, according to Manny Vara, a spokesman for Intel. The 350-MHz, 400-MHz, and even 450-MHz chips don't really need it, he said, but above 500 MHz, this new casing will be important.

Heat sinks, or fans, are now connected directly to the CPU and its covering. The CPU covering, which wraps the bare CPU die and Level 2 cache, is also new. Intel is replacing the old Plastic Land Grid Array (PLGA) wrap with a wrapper called Organic Land Grid Array (OLGA), an organic substrate that uses copper.

The new design is for Pentium II chips only. The high-end Xeon chips will also get the OLGA substrate, but the casing will remain the same, said Vara.

The copper in OLGA conducts the electrical signal in the CPU far better than the PLGA's plastic substrate. The OLGA substrate also allows for connecting the heat sink directly to the substrate, rather than requiring the metal plate like the old systems.

The new casing is called Single Edge Contact Cartridge 2 (SECC), and will still fit in Slot 1 Pentium II motherboards, but will be thinner than the current form factor. The major change in SECC 2 over the previous generation is Intel has removed the thermal plate on the back of the casing, where the heat sink was attached. "As we crank up the MHz, the thermals go back up," said Vara. "Beyond 500 MHz next year, there are changes you need to make [to the design] to deliver those kind of MHz."

The old design never made any sense, according to Keith Deifendorff, editor in chief of The Microprocessor Report, a newsletter in Sunnyvale, Calif.

"I never understood the purpose of the heat plate, because it does get in the way of cooling," he said. "This was an obvious good thing to do. It's something I wondered why they haven't done before."