Although most software in the market is still 32-bit-based, an increasing number of applications such as databases need more power to drive them, and 64-bit processors are a solution.
AMD was the first to offer its Opteron processors working in 32-bit and 64-bit mode, and Intel recently followed up with the announcement that its Itanium and Xeon processors will support dual working in the future.
Both firms are using chipset modifications or "extensions" to the processors to allow this.
HP, which has in the past relied on Intel chips for its server line, is now offering its Proliant server family with AMD andIntel chips with extensions.
The way HP has packaged the re-launch of the Proliant range has drawn criticism from analysts concerned about user confusion. For instance, HP said AMD 800 series processors with extensions on its Proliant 500 series server would be targeted at "high bandwidth/low latency applications" and "mid-tier databases".
Rakesh Kumar, an analyst at Meta Group, said, "This approach by HP does cause confusion among users. This marketing should be replaced by discussions behind the scenes with technical people at customer sites."
Martin Hingley, an analyst at IDC, agreed. "Users do not really know what 64-bit is, but they do know they are running out of memory," he said.
Thomas Ulrick, HP's Emea director of marketing for the enterprise group, said, "Some firms have requirements for using AMD processors and we wanted to address that. Where there is a choice, some customers may need help, but many will not."