A Chip War of EPIC Proportions

FEATURE: The age-old debate between x86 and RISC chips for servers has taken a turn with the advent of the EPIC-based Itanium and the return of CISC-style chips like the Opteron.

Once, RISC-based server machines were faster and more powerful. But now many IT buyers now are abandoning the once-popular UNIX architecture because of their proprietary nature and instead opting for advanced x86 architectures, which are starting to match UNIX in computing power but are cheaper to maintain.

But instead of a two-horse race, the development of Intel's EPIC-based Itanium family and AMD's CISC-style Opteron is giving server customers more choices and forcing vendors to take cutthroat measures.

Tainted Love
It was back in the mid-1980s, when a number of computer manufacturers such as Sun Microsystems , IBM Digital Computer's Alpha (now owned by Hewlett-Packard) decided to build CPUs capable of executing only a very limited set of instructions, referred to as a reduced instruction set computer (RISC). Prior to that, computer makers built increasingly complex chips that had ever-larger sets of instructions, commonly known as a CISC.

It was during this time that Intel continued to improve its x86 line of chips, which had been primarily made for desktop PCs, and begin to win much of the mid-range market with its Xeon processors. Recently, AMD has challenged that thinking with its 64-bit Opteron. That processor, launched in April, is backwards compatible with 32-bit based systems and is considered more of a CISC than a RISC chip.

To some extent, some say the argument between architectures is becoming moot because each of the processor's implementations is becoming more and more alike. For example, many of today's RISC chips support as many instructions as yesterday's CISC chips. And today's x86 chips use many techniques formerly associated with RISC chips.

All of which has analysts wondering which technology will be the choice of customers once IT spending returns in full.

"The difference is that the x86 architecture evolved, while RISC chips never got into the mainstream market," InStat/MDR analyst Kevin Krewell told internetnews.com. "With Intel you get a new server architecture design every two years with a speed difference. In the server business, things don't move that fast. Legacy is a wonderful thing, however. IT guys don't like ripping out systems that work."

Alpha Dog

Keeping legacy around and keeping what is working is a concept that has played well through the tough times but does not sell well with companies trying to sell chips or servers. Hence, HP's decision to team up with Intel to build a completely new chip in the Itanium.

"When we went down the EPIC path to look at the past 20 years in computing be it the CISC or RISC product lines and decided to build a better architecture," Intel Itanium product line manager Mike Graf said. "We think we have a better mouse trap."

Based on HP's Explicitly Parallel Instruction Computing (EPIC) design, the chip looks at instruction level parallelism to tackle separate problems at the same time.

Despite being on the market for two years, Itanium migration has been slow.

"The companies that are mostly on Itanium are HP SGI and to some extent Unisys," said Krewell. "It has x86 compatibility, but it needs new software and software has been very slow coming. In the midst of a recession, it was hard to migrate to a new spending."

Krewell says more Itanium adoption will probably kick in with the release of low-voltage versions of the chips currently codenamed Madison and Deerfield. Due out this year, the processors are similar to current McKinley structures but shrunk down in size and running cooler. The suggestion is that the chip could find its way into blades or thin clients, which had previously been a barrier.

There is also some speculation into how many Itanium chips have been sold. Intel gave away many of its chips to its partners and the company has a policy not to release specific numbers about how many chips it sells.

Sources at the Inquirer estimate Intel has sold 370 Itaniums in 2001, 2700 in 2002 and expects to sell 7,000 of the chips by the end of this year.

The chip has made some rumblings in classic RISC circles. Most notably a recent TPC-C benchmark that put HP's Superdome running Microsoft Windows Server 2003 Data Center Edition over Itanium 2 chips. The combination upset IBM's rule with its AIX/RISC/DB2 stack.

Down, But Not Out
While the RISC manufacturers seem to be on the ropes, they are certainly not dying out any time soon.

Sun is currently working on a UltraSPARC chip that takes 6 to 8 cores and puts them on one die. That means that each of the chips will be able to handle up to 32 threads simultaneously. The chip is part of Sun's Throughput computing initiative, currently code-named Niagara.

IBM is also looking at doing multi-core processing with its upcoming PowerPC 5 and PowerPC 6 lines.

"I don't see Sun giving up on UltraSPARC and people thought IBM was going to jump on the Itanium bandwagon, which they haven't," said Krewell. "Certainly they see their Z-series, which is their flagship mainframe processor, as just as good or better than anything that Itanium can offer."

Krewell says Intel's benefit is that they now have the team that designed the Alpha chip under its wing.

"They were widely admired from an engineering standpoint, it's just that DEC never knew what to do with the technology and Compaq had so many products, that it wasn't able to market the line," Krewell said.

Ultimately, it is up to the customer to decide what types of computing they want.

"Take for example, what they are doing over at Google," Krewell said. "They've taken a volume technology approach with PC platforms, hundreds and hundreds of vanilla boxes broken up over a large area so that when one dies it is replaced without losing the data. If you are dealing with a banking system, I don't think you would want to do it over a bunch of PC platform in a warehouse somewhere but if you are trying to run a huge data center or solve complex problems like NEC's global climate simulator, you would want faster chips that are scalable and more reliable."






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