Xeon Replaces Pentium Pro: 7/13/98
Total Page：16
File Type：pdf, Size：1020Kb
1997 COMPUTER PRESS ASSOCIATION WINNER ♦ BEST COMPUTER NEWSLETTER VOLUME 12, NUMBER 9 JULY 13,1998 MICROPROCESSOR REPORT THE INSIDERS’ GUIDE TO MICROPROCESSOR HARDWARE Xeon Replaces Pentium Pro Intel Targets Servers and Workstations by Keith Diefendorff sure applied on the low end by AMD, Cyrix, and IDT. The problem for Intel is that it needs a high ASP to fuel the semi- Intel has plugged the gaping hole at the top end of its conductor R&D and fab improvements that keep it ahead of product line—previously served by the aging Pentium Pro— its competitors. with a Deschutes-based processor module the company Having so far failed to stimulate demand for higher labels Pentium II Xeon. As Figure 1 shows, the new processor performance (and higher priced) processors in PCs, Intel family will serve the midrange to high-end server and work- will try to take a larger share of the higher-margin worksta- station markets until the 64-bit Merced processor enters ser- tion and server markets. While these markets are each about vice in 2000. only 1% of the size of the PC market in unit volume, they can Pentium Pro was previously the only processor in easily bear 10 times the processor price. This fact makes these Intel’s lineup capable of addressing this high-end segment, markets immensely profitable and gives Intel an opportunity because it’s the only processor that supports four-way multi- to increase revenue and ASP. processing (MP), memories larger than four gigabytes, and Beyond the desire to prop up revenue and ASP, Intel fast ECC L2 caches larger than 512K—all minimum require- realizes that strategically it needs to own the markets on both ments of the high-end market. But Pentium Pro, still in 0.35- sides of its core desktop-PC business to guard against com- micron technology, tops out at a paltry 200 MHz and sup- petitors gaining a foothold and attacking from above or ports only a 66-MHz system bus. These factors saddle it with below. Having already made the mistake of allowing that to anemic performance relative to its RISC competitors. Xeon matches Pentium Pro’s MP, memory, and L2 capa- 3Q98 4Q98 1H99 2H99 Xeon bilities, plus it raises the system-bus speed to 100 MHz and dra- 400 MHz 450 MHz 500 MHz 700 MHz matically boosts CPU speed to 400 MHz and beyond. Xeon is Midrange to 512K, 1M 512K–2M 512K–2M 1M, 2M High-end 0.18µ supported by two new chip sets (see MPR 7/13/98, p. 11) and Workstations & Deschutes Deschutes Tanner Tanner by an Intel-built L2 SRAM that runs at the processor’s full core Servers frequency. Xeon and its companion SRAM(s) are packaged Pentium II 400 MHz 450 MHz 500 MHz 600 MHz 512K 512K 512K 512K together on the new Slot 2 module (see MPR 3/30/98, p. 14), Performance 0.18µ Desktop which uses the same bus protocol as Slot 1 but supports four- Deschutes Deschutes Katmai Katmai way SMP systems, has greater cooling capacity, and is physi- cally larger (to accommodate more L2 cache). Celeron 300 MHz 333 MHz 333 MHz 400 MHz 128K* 128K* 128K* The new processor is available now at 400 MHz. With Basic PC Desktop 512K and 1M L2 caches, it is offered at essentially the same Covington Mendocino Mendocino Mendocino $1,100 and $2,800 price points as the Pentium Pro it replaces. Later this year, a 450-MHz version will become available, Mobile 266 MHz 300 MHz 333 MHz 366 MHz probably at similar price points. We expect the 2M cache ver- Pentium II 512K 512K 256K* 256K* 0.18µ sion of this processor, however, to command a stratospheric Mobile PC Deschutes Deschutes Dixon Katmai price (relative to PC processors) close to $3,500! Available Source: Intel Source: MDR Xeon Challenges RISCs at the High End Figure 1. Intel divides the market into four segments, with Xeon Lately, Intel’s overall average selling price (ASP) has taken a taking the high ground. Shown are the fastest processors Intel will beating from declining PC prices and from competitive pres- field in each segment over the next year. (*indicates on-chip L2) Inside: Xeon Chip Sets ♦ IBM C54xDSP ♦ Savage3D ♦ MGA-G200 ♦ Banshee 2 XEON REPLACES PENTIUM PRO happen on the low end, Intel cannot afford to repeat the error neither is suitable for the other’s market allows Intel to ask on the high end. Actually, it may already have done so by fail- completely different prices for them. ing to field a viable RISC processor. But, thankfully, its RISC Second, Intel is attempting to stratify the market seg- competitors failed to capitalize, and Intel now has a second ments in the minds of customers with a strong branding opportunity to avoid that mistake. campaign. Branding, Intel hopes, will obscure the underlying Intel also recognizes that technology flows downhill. microprocessor, thus freeing its products to follow the pric- Now that Intel has usurped most of the good ideas from the ing models appropriate for their respective segments. A sec- mainframes, it must create its own technology. Bleeding- ondary benefit of branding is that it gives Intel cover for edge technology is best developed in the context of a high- migrating from one generation of processor to the next. Cus- end business, because the loftier prices make it easier to tomers, other than geeks who pry off lids or read this newslet- fund, and the lower volumes make it less challenging to ter, may never know what microprocessor is in a future deploy. Celeron or Xeon. Intel’s long-range plan is to capture the high-end mar- Considering the competitive workstation and server kets with its new IA-64 architecture. But the first implemen- landscape, Intel seems justified in demanding high prices for tation, Merced, has now been delayed to mid-2000 (see MPR Xeon. Competitor Sun, for example, charges $3,961 for its 6/22/98, p. 1). Neither Pentium Pro nor Slot 1 Pentium IIs are 360-MHz Ultra-2 module (see MPR 5/11/98, p. 5). Also, the strong enough to capture a significant share of these markets market appears capable of supporting such prices. After all, if from the RISCs. Xeon represents Intel’s interim attack on a $1,500 PC can use a $300 processor, then surely a $15,000 these markets. workstation or server can support a $3,000 processor.Viewed in this way, the Xeon prices do not seem excessive. Intel Segments the Market by Branding Significant obstacles block Intel’s attack on both the low- and Pentium II Patched for Server Duty high-end markets. On the low end, Intel’s competitors have Within the workstation and server markets, Intel differenti- successfully built competitive processors on Socket 7. To ates between midrange-to-high-end systems and “volume” avoid further legitimizing Socket 7, Intel has been forced to systems. The volume systems, generally those below about push the market to Slot 1 and abandon Pentium. $5,000, will continue to be served by Pentium II. Xeon is Without Pentium, Intel is left with one processor, aimed at systems above $5,000. In fact, Intel has taken spe- Deschutes, to serve the entire market spectrum. This is not cific marketing and product actions to prevent crossover. just a technical challenge, it’s a business challenge: how is it To encourage companies to use (pay for) Xeon instead possible to charge $100 on the low end yet justify $3,500 on of Pentium II in the high-end markets, Intel left a few key fea- the high end—for exactly the same microprocessor? To tures out of Pentium II, as Table 1 shows. Chief among them charge less on the high end would just be leaving money on is its inability to go above two-way SMP. the table—not something Intel likes to do. While Deschutes implements the full cache-coherence The company has two solutions: repackaging and brand- protocol for n-way SMP operation, the 242-pin Slot 1 inter- ing. First, Intel will repackage Deschutes to target specific mar- face has signal-integrity limitations that prevent Intel from ket segments. For example, Celerons today are packaged with certifying its operation above two-way. High-end servers, no L2 and limited to 300 MHz for the low end, whereas Xeons however, require four-way SMP capability. The additional 58 have large, fast L2s and run at 400 MHz for the high end. power and ground pins on Xeon’s 330-pin Slot 2 interface, Although the manufacturing-cost or performance differences and its use of AGTL+ (assisted Gunning transistor logic) sig- between them do not justify a huge price delta, the fact that naling, provide the additional signal integrity necessary for 100-MHz four-way SMP systems. Feature Pentium Pro Pentium II Xeon AGTL+ is similar to Pentium II’s GTL+, but AGTL+ sig- CPU Frequency 200 MHz 400 MHz 400 MHz nals are driven to VCC for one clock cycle after a low-to-high System Bus 66 MHz 66 or 100 MHz 100 MHz transition to improve rise times and reduce noise. As with Interface Socket 8 Slot 1 Slot 2 GTL+, the input receivers are differential for good noise Package 387 PGA 242 SECC 330 SECC Max L2 Size 1M 512K 1M (2M 4Q98) immunity, but with Xeon the VREF generator was moved onto L2 Speed 200 MHz 200 MHz 400 MHz the processor. Since AGTL+ is electrically compatible with Chip Set 450GX 440BX 440GX, 450NX GTL+, it is possible that all Pentium IIs could go to AGTL+.