Hewlett-Packard continues to develop plans to transition its customers from systems based on its proprietary CPU to servers built around Intel's IA-64 processors.
But the company is hedging its bets by continuing to develop PA-RISC, giving IT managers the option to stick with the technology through 2003 and beyond.
If Merced and its follow-on IA-64 chips gain a performance advantage over PA-RISC, Alpha, or Sparc, users of those CPUs will switch quickly, according to Nathan Brookwood, principal analyst at Insight 64, a consultancy in California.
In the meantime, users have to buy what is available.
"People have problems to solve today," Brookwood said. "They can't wait for IA-64."
HP, for its part, is continuing its development of PA-RISC and recently introduced a 360MHz PA-8500.
This chip is expected to run at 440MHz next year, and HP will offer a working technology demonstration of a 500MHz PA-8500 at the San Francisco International Solid-State Circuits Conference (ISSCC) in February.
Beyond that, HP has planned a PA-8600, which will debut in mid-2000 and run at about 560MHz, according to Scott Emo, technology marketing manager at HP.
The PA-8700, on the road map for 2001, will offer 720MHz speeds, and the PA-8800, ready in 2002, will run at about 900MHz. HP will break the 1GHz level in 2003 with the PA-8900.
"IA-64 eventually will be the way to go," Emo said, "but we want to have a parallel path [with PA-RISC]."
HP will use dynamic translation to run PA-RISC software on IA-64, eliminating the need to recompile, according to Emo.
For best performance, though, users will have to recompile PA-RISC programs on IA-64.
To improve the performance of the PA-RISC architecture, the PA-8500 uses a 1MB Level 1 (L1) data cache memory and a 500KB L1 instruction cache memory.
With this much L1, "you don't need L2 cache", Emo said.
Operations are accelerated because they don't have to go through L1, L2, or even sometimes L3, Emo explained.
"You do not have to go through a hierarchy," Emo said.
At the same ISSCC session, Intel will offer a technology demonstration of a 600MHz Katmai processor.
Katmai will debut early next year at 450MHz and 500MHz, and while faster versions will follow, it is unlikely that commercial versions will ever reach 600MHz, an Intel representative said.
Instead, the IA-32 family will pass 600MHz with the introduction of the Cascades and Coppermine processors, around mid-1999.