Long-Awaited "Foster" Xeon MP Chips Announced

by Timothy Prickett Morgan

The Fosters are similar in some ways to the "Prestonia" Pentium 4 Xeon chips that Intel debuted a few weeks ago at its developer's conference. (See the February 27 edition of Guild Companies for detailed information on the Prestonia Xeons and their associated "Plumas" E7500 chipset for dual-processor workstations and servers.) Intel started delivering two-way capable Foster processors for workstations last May using its i860 processors; the Prestonias are similarly engineered to support only dual-processor capable machines. But the new Xeon MPs can support four-way servers, and can also be used in more scalable servers from IBM, Unisys, and others who have designed their own chipsets to use these four-way Intel processors as the basic component to create machines with anywhere from 8 to 32 processors in a single system image. (I will profile the server announcements made by the major server vendors as it relates to the Foster chips in next week's issue.)

Like the Prestonia, the Foster MP processors support a technology that Intel calls Hyper-Threading, which is a sophisticated trick of chip electronics that virtualizes the instruction pipelines in the Pentium 4 Xeon processor and allows Intel to re-jigger them so a single processor chip looks like two processors as far as the operating system is concerned. Hyper-Threading technology can boost processor performance between 15 percent and 30 percent, and it will be a welcome addition to the technologies that server customers want to exploit. The Foster Xeon MPs are also the first chips from Intel to include an on-chip Level 3 cache. All modern Intel processors (and many of these from competitors have on-chip L2 caches) and all chips sold in servers have long since included on-chip L1 cache to boost performance. The Foster Xeon MP processors have the same 256 KB L2 caches that were on the original Foster Xeon chips from last year and the current Prestonia Xeon chips. However, the Foster Xeon MP chip has either 512 KB or 1 MB of L3 cache also integrated on the chip. Many server vendors who are extending their server designs beyond four-way SMP are adding yet another layer of cache memory, Level 4, to their machines to help boost performance and keep those hungry Foster chips well fed with data.

The Foster Xeon MPs come in three speeds, 1.4 GHz, 1.5 GHz, and 1.6 GHz. The 1.4 GHz and 1.5 GHz versions of the chip have 512 KB of L3 cache and the 1.6 GHz version has 1 MB of L3 cache. Right now, IBM's XA-32 Summit, Unisys' CMP, and ServerWorks' Grand Champion chipsets are the only ones supporting the Foster Xeon MP processors. There will be additional chipsets for Foster MPs coming from Intel, Compaq, and possibly others. Server vendors expect Intel to have the Foster Xeon MP chips shipping in appreciable volumes by this time next month in their products, pushing out toward the end of the month. The 1.4 GHz Foster Xeon MP processor sells for $1,177 in 1,000-unit quantities. The 1.5 GHz version costs considerably more at $1,980, and the 1.6 GHz version with the larger L3 cache costs $3,692. While the price of that fastest Foster Xeon MP seems high relative to the only moderately slower 1.4 GHz version (at least in terms of clock speeds), similar RISC processors used in Unix servers that have half the clock speed or less of the Foster MPs and deliver roughly the same performance in midrange servers that sell for anywhere from three to six times that price. Incidentally, those Foster Xeon MP prices are identical to the prices Intel has been charging for its 700 MHz and 900 MHz Pentium III Xeon processors.