The Big Bang in Hardware

The past decade was very exciting as far as computer hardware goes. Lots of new technologies were introduced, and computing power grew by leaps and bounds. To name a few significant trends, processor speeds crossed the Gigahertz barrier; hard drive and RAM capacities went through the roof; and all basic functionalities such as sound, networking, modem and graphics were integrated in the motherboard. That’s why everyone noticed the individual technology changes, but not what it did to computing overall. So the ‘wow’ effect comes only when we look at the computers of today, and compare them to those a decade ago. But it seems that things are going to change this year.

A lot of technological development in hardware will be seen towards the second half of this year. It’s likely to have a major impact on the computers of the future, so it makes sense for everyone to be aware of what to expect, right from the home users to large enterprises. We’ll talk about the technology trends that wil shape tomorrow’s PCs in this article. Subsequent articles in this section will cover the specific technologies that will make it happen.

From shared to switched





The first notable effect of this trend was seen on Ethernet networks, which was originally a shared network. In other words, it used a hub to connect clients, so, whenever a client wanted to comcate with another, its packets were broadcasted across all ports of the hub. If there were too many clients connected to a hub, it resulted in packet collisions, thereby reducing performance. Things changed with the introduction of a network switch, which provided a direct and dedicated connection between any two clients connected to its ports. A 10 Mbps switch ensured that it gave dedicated bandwidth on each of its ports.

A similar situation exists in a computer with a PCI bus, which is a parallel architecture offering a maximum throughput of 133

MB per sec. It’s a shared bus, ie, all devices that connect via this bus, such as sound, network and IDE hard drives, share the same bus and amount of bandwidth. Till now things had been fine, because none of these devices were powerful enough to overload the bus, even collectively. However, now that throughput intensive technologies such as Gigabit Ethernet, SCSI and RAID have emerged, this bus will prove to be a bottleneck. Enter PCI-Express. While the standard for this bus was approved in April 2002, products supporting this bus are only expected to come out this year. The bus adds a new element called a switch into the motherboard architecture. This switch creates point-to-point links between various devices, and offers serial communication between them, with each point-to-point link capable of delivering a data rate of 2.5 Gb per sec. Since the shared bus is eliminated, it will mean better throughputs, and hence better per-

formance.

From parallel to serial



This is another interesting trend noticed in the hardware industry. We’ve already talked about PCI-Express, which basically creates serial point-to-point links to different devices. The result of this is that throughputs can be scaled up significantly, because the circuitry required to do that on a serial link is far simpler and less expensive to make, compared to a parallel link. The evolution of Ethernet from 10 to 100 to 1000 Mbps is a classic example of this. The other classic example is SerialATA, which was introduced sometime last year. SerialATA is meant to replace the current parallel ATA interface in IDE hard drives. Reason for that is again the same. Parallel ATA had reached its throughput limit. With SerialATA, there’s a well-defined roadmap to scale the throughput up significantly. SerialATA I based hard drives can support up to 150 MB per sec throughput, while those based on SerialATA II, expected to appear sometime this year, will offer double that throughput.

DDR II is the successor to DDR memory

This is expected to go up further in the future. A similar thing is happening on the SCSI front, which was also a parallel interface. The new technology is Serial Attached SCSI or SAS, which is the next upgrade to Ultra360 SCSI, and offering throughputs up to 300 MB per sec. The standard for this was ratified sometime in January this year, and already companies are planning to launch their products based on this standard. Fujitsu for instance, plans to introduce a 73.5 GB hard drive some time this year.

Faster memory



Another component that’s seen a radical evolution is the memory. From asynchronous EDO RAM (Extended Data Output RAM) a decade ago, we moved to Synchronous SDRAM, which then evolved into Double Data Rate or DDR SDRAM, which could pump data twice as fast as the original SDRAM. The next logical evolution is towards DDR II, which doubles the throughput of DDR memory and can be scaled up further. In simple English, SDRAM pumped a bit of data on every clock cycle. DDR RAM managed to send two bits per clock, one on the rising and other on the falling edge of the clock. DDR II will double the throughput of DDR by doubling the clock frequency itself.

New motherboards and processors



The last logical connection to these trends is the playground for all these technologies, which is the motherboard. Significant changes have to be made to the motherboard architecture in order to accommodate these new technologies. The chipset has to change to support PCI-Express, and since this will also reduce the trace routes on the board, the motherboard design will become more compact. This year, a new form factor is being introduced, called BTX (Balanced Technology Extended), which is the next version of ATX. BTX based boards will take care of some of the deficiencies found in ATX board, related to the cooling, noise level and compactness. So BTX boards would have a more logical placing of components, simplified circuitry with PCI-Express, which would result in more compact motherboards.

As we can see, there will be some radical architectural changes in computer hardware, most of which is slated to happen sometime this year. If you’re interested in knowing more about these technologies, then read the next few pages. We’ve discussed them in

detail.

Anil Chopra