Answering the question "What's of most interest in the Power Mac G5?", Macworld readers are firm in their conviction that IBM's PowerPC 970 (dubbed the G5 by Apple) is the most important part of a machine that's stuffed full of next-generation technologies and components.
1,202 of the 1,984 voters - 61 per cent of those polled – said the 64-bit G5 was the most exciting new component.
Way back in second place is the Power Mac G5's faster frontside bus speed (up to 1GHz), which garnered 18 per cent of the vote. Each PowerPC G5 processor has its own dedicated bidirectional interface to the system controller offering up to 16GBps of total bandwidth – which Apple claims is more than twice the 6.4GBps maximum bandwidth of Pentium 4-based systems using the latest PC architecture. In addition to providing fast access to main memory, this high-performance frontside bus architecture enables each PowerPC G5 processor to discover and access data in the other processor’s L1 and L2 caches for ultra-fast performance.
Cool dude Four per cent of the vote went to Apple's smart cooling system that allows the Power Mac to run so fast – and remain relatively quiet. The Power Mac G5’s enclosure houses four discrete thermal zones to compartmentalize the primary heat-producing components. Fans in the zones spin at very low speeds resulting in a system three times quieter than the Power Mac G4.
The new HyperTransport interconnect technology won 3 per cent of all the votes. The HyperTransport protocol integrates the Power Mac G5’s I/O subsystems and connects them to the system controller. Serial ATA, Gigabit Ethernet, FireWire, USB 2.0 and optical digital and analogue audio are all integrated through two bidirectional 16-bit, 800MHz HyperTransport interconnects for a maximum throughput of 3.2GB per second.
Just 1 per cent of the readers were adamant that the Power Mac's 400MHz dual-channel memory was the most interesting aspect of the system architecture. Apple argues that this effectively doubles the bandwidth, enabling the Power Mac G5 to reach a maximum memory throughput of up to 6.4Gbps.
An equal percentage voted for Apple's inclusion of 480Mbps USB 2.0, which is rather eclipsed by the 800Mbps FireWire 800 – although there are more USB 2.0 devices available at the present time.
Forgotten techs Serial ATA, PCI-X, and AGP 8x technologies registered the fewest votes. Designed to meet the demands of digital video editing, 3D modelling and other data-intensive applications, Serial ATA is the next-generation industry-standard storage interface that replaces the typical (Parallel) ATA interface. Since each Serial ATA drive is on an independent bus, there’s no competition for bandwidth as with Parallel ATA. The PCI-X protocol increases the PCI bus speed from 33MHz to 133MHz, and the throughput from 266MBps to a combined total of 2GBps. PCI-X also operates more efficiently, giving you more usable bandwidth at any clock frequency. he 66MHz AGP 8X Pro bus strobes eight times per clock cycle, resulting in a 533MHz data rate and blistering bandwidth of 2.1GB per second.
That said, 11 per cent of Macworld readers weren't interested in the interior components at all. They voted for the G5 Power Mac's "funny cheese-grater looks".
Read the whole Power Mac G5 poll debate here.