Intel Chip Puts Pentium II in Overdrive

When Intel Corp. added MMX and its 57 new instructions to its line of Pentium processors, the technology quickly became a staple. Shortly thereafter, Intel promised to offer to Pentium Pro processor-based systems that shipped before the advent of MMX an upgrade path to the new multimedia technology. To follow through with that, the company released the Pentium II OverDrive Processor.

The OverDrive chip upgrades existing 150- and 180-MHz Pentium Pro processor-based systems to 300 MHz and upgrades 166- and 200-MHz chips to 333 MHz. Intel claims that, along with larger cache, the OverDrive chip will enhance system performance for desktops, workstations and servers. "Business users today demand more power from their PCs than ever before," says Jim Yasso, vice president, Intel Architecture Business Group. "Now owners of Pentium Pro processor-based systems can bridge to Intel’s MMX technology."

The OverDrive chip is built on Intel’s 0.25 micron process and shares the same processor core as Pentium II and the newer Pentium II Xeon processors. Because it is built with Pentium II technology, the OverDrive processor has many of the same features, including Dual Independent Bus Architecture, Dynamic execution, 32-KB L1 cache, and a closely coupled 512-KB L2 cache. The L2 cache bus runs at the full speed of the processor, thus enabling the CPU to process faster. "The OverDrive is a Xeon by any other name," says Rob Enderle, senior analyst, Giga Information Group (Santa Clara, Calif.). "It’s a cheaper way to get the megahertz power and cache of the Xeon."

However, upgrading with the OverDrive does not provide all the advantages of the Xeon chip. Processing power is increased, but the OverDrive does not change the motherboard, and it does not provide the core speed and improvements in the chipset that makes the Xeon valuable.

Given that even some corporate PCs have fallen below $1,000, and even low-end machines ship with MMX technology, this chip may not find a home in many desktop systems. After all, if MMX is what you’re after, a new machine may be inexpensive enough that it’s easier and more economical to simply buy a whole new system than it is to upgrade via the OverDrive.

But servers are not so easily replaced. With the OverDrive, administrators can inexpensively upgrade servers to have MMX, faster processors and more L2 cache, all of which enhance performance. "Typically, MMX is not important to servers. But L2 cache and a faster processor are," says Enderle. He points out that upgrading servers with the OverDrive chip is not unrealistic. "This is not a new concept. This is known technology, so upgrading is relatively safe."

Not all servers need to be upgraded, though. File and print servers, for instance, won’t gain much from the OverDrive processor. Application servers are where this chip is most likely to earn its keep.

However, the real sweet spot for the OverDrive chip will probably be for the power workstation user, a market in which Intel is fighting to establish a presence. "The workstation is more technically inclined than the desktop market, so the chip is more likely to be used in workstations," says Enderle.

Since workstations are typically $4,000 to $6,000 apiece, upgrading for $600 is attractive. "The chip will allow companies to delay replacing equipment for a year and a half. There’s a value because the workstation market is not so hot now, so companies may want to wait until next year to buy new machines," says Enderle.

But upgrading and delaying the purchasing of equipment are not the only reasons the company created this chip. "Intel basically built this chip because the company promised it would. If they didn’t, Intel would probably be sued," says Enderle. "I don’t know if they’ll ever do something like this again."