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64-bit computing, Power, and the iSeries: History foreshadows the future

      In 1995, the iSeries was the first server to debut IBM’s 64-bit chip. In 2004, the iSeries was the first to debut the Power5 architecture. Looking into the future of 128-bit computing, the iSeries is expected to lead the market once again.

      “Today (with Power4 and Power5) we have a single chip that has two 64-bit processors on it. It would be very easy to have a single 128-bit processor on that chip, because it is essentially the same. 128-bit [computing] is probably the end of the decade at the earliest, and that is just a guess,” says Frank Soltis, iSeries chief scientist, IBM, Rochester, MN.

The iSeries fit the bill in the past

      As 64-bit computing and IBM’s Power architecture have evolved over the past decade, the iSeries has played an integral part in the rollout of these technologies. Back in the mid 1990s, why did IBM decide to debut the first 64-bit chip on the AS/400? Soltis says the timing was just common sense to IBM.

      “One of the things that we [at IBM, Rochester] noticed in the early 1990s was that there were a number of new types of applications that [AS/400] customers were starting to use. Many of these were very numeric, computing-intensive applications. A good example would be the whole world of business intelligence involving data mining and data warehousing. We also saw that there were new languages being used — a prime example of that is Java. We started work on a new processor shortly after we announced the AS/400, and it was just logical for us to move to a 64-bit implementation for Power,” says Soltis.

      The history. “In late 1990 and leading into 1991, we (in Rochester) were looking at a new processor for the AS/400. One that we looked at was the Power processor, and we quickly concluded that it wouldn’t work in its current [32-bit] implementation [in the RS/6000], because it was missing a lot of things that we needed for the server [AS/400]. So, I was asked to lead an effort within IBM to take the Power architecture and extend it to a full 64-bit server architecture. We built the first implementation of chips that supported 64-bit and shipped it in 1995 in the AS/400,” says Soltis.

      He continues, “A lot of people missed the point of what it meant to go from 32-bit to 64-bit. People were saying that it was just to get a larger address. That is part of the reason, certainly, but there is a bigger reason for it, and that is throughput. That means that when it [the address] is extended to 64-bit, the amount of data that can actually be pushed through in a single cycle is doubled.”

      The iSeries reaped the benefits once again by being the first eServer to debut Power5 technology (IW 5/10/04). “The Power processor has given the iSeries the long-standing recognition of being a flexible and scalable server, and the new Power5 capabilities play well into that tradition. The 64-bit processor enables applications on the iSeries that require a great deal of intense support data and large databases to run smoothly,” says Charles King, research director, Sageza Group, Mountain View, CA.

How will the iSeries fit the bill in the future?

      As these technologies continue to evolve, the iSeries is expected to continue to play a leading role in the advance of 64-bit to 128-bit computing and IBM’s Power architecture — but not until 64-bit computing catches on in the overall market.

      “You are not going to see 128-bit for a while, because the industry is going to spend some time getting to 64-bit — but I am a big fan of 128-bit computing. When I did the design of the original AS/400, the team of people that I was working with had to decide what the size of the address would be. We, as engineers at the time, anticipated that by now we would be at 128 bits. So, the address carried along in every AS/400 and iSeries is 128 bits — only 64 are used today, but we carry 128. So, at some point in the future, when the hardware world jumps beyond 64-bit, the iSeries is already capable of going to 128-bit computing,” says Soltis.

      Even though the capability to extend to 128-bit is already built into the iSeries, the capability and need will have to be present in the market before the iSeries sees this technology. “Ten to 20 years from now, 64-bit will not be enough for enterprise applications. Then, we can start talking about 128-bit,” says Wayne Kernochan, president, Infostructure Associates, Wellesley, MA.

      For more information on 64-bit computing and IBM’s Power architecture, see the Sageza Group reports “Welcome to the Revolution: Disruptive Technologies and 64-bit Computing,” and “IBM POWER as an Industry Standard,” authored by Charles King in March and June 2004, respectively.