John Chamberlain
Developer Diary
 Developer Diary · You Heard It Here First · 22 November 2003
The Multi-Gig Memory Potential Behind 64-bit Computing
An important change occurring in the hardware market is the switchover to 64-bit chips. Sun has showed some energy in adopting the new AMD Opteron chips as a possible standard offering for their servers. Sun has had the 64 UltraSPARC architecture for years now, but what should have been its hey-day has in fact been a period of dwindling profitability. The reason for this is that the 64-bit machines are signficantly more expensive but do not offer much greater performance than a clone box. Also, they tend to be more difficult to manage in a number of ways. An even more fundamental question is whether that performance is important at all anyway. Nowadays a scientist can easily do 3D renderings and visualizations on clone boxes that would have required an expensive workstation only a few years before. Why even bother with 64-bit?

The reasons why 64-bit is not significant to standard performance are that if your application is moving around 32-bit words which 99% of them do, the 64-bit does not help you all. Unless you are the Federal Reserve most people are working with numbers below a billion. Where 64-bit becomes important is not performance directly so much as the ability to access more than 4 gigabits of memory. Since there are currently few applications or hardware configurations, Sun's included, that use more than 4 gigabits this key ability of 64-bit processing has gone wasted.

The Hope for 64-Bit: Multi-Gig Memory on the Horizon

The wasted and useless 64-bit chip may be about to experience a Phoenix-like rebirth because of the emergence of multi-gigabit memories. It is now becoming economically feasible to have more than 1 or 2 gigabits of memory in a machine and software is being written to reflect this fact. These new programs will require 64-bit processors to achieve full functionality. This is why the Opteron has such a great potential.

For Sun, however, the question still remains whether it will be better for users to simply buy clone PCs with Opteron running UltraLinux rather than buy an expensive Sun box. If Sun could make a superior port of 64-bit Linux that was cheap and better than anything else standing that would suddenly make a compelling reason reason to buy a Sun box in a multi-gigabit world. Will it happen? Time will tell.

Developer Diary · · bio · Revised 22 November 2003 · Pure Content