In terms of architectural changes, the most noticeable is the Opteron’s integrated memory controller — a 128-bit, dual-channel design supporting DDR266 and DDR333 SDRAM. Both the Opteron’s memory controller and the Athlon 64’s — a single 72-bit channel — take that job away from its traditional place in the system chipset’s external Northbridge, greatly reducing the latency of read/write requests. This essentially controls the system at, or yields a front-side bus speed matching, the clock speed of the CPU.
With the new Opteron comes a gutsy new numbering scheme. AMD says the first digit in the model number communicates scalability, and represents the maximum number of processors supported by that model number:
- AMD Opteron processor 100 Series (Example: Model 1XX) = 1-way server
- AMD Opteron processor 200 Series (Model 2XX) = 2-way server
- AMD Opteron processor 800 Series (Model 8XX) = supports up to 8-way servers
The second and third digits communicate relative performance within each product line. In this case an Opteron Model 244 will offer higher performance than an Opteron chip Model 242.
AMD started numbering the last two digits at 40. The company also says the Model numbers are not directly related to frequency.
It seems obvious that Intel will continue to hold the clock-speed advantage (its Xeon currently peaks at 3.06GHz), while AMD might well win the performance race — it’s shown estimated 32-bit benchmark results that show a 2.0GHz Opteron comfortably ahead of the 2.8GHz Xeon.
Partners Line Up
Already jumping on the bandwagon is Microsoft, which has pledged to support the architecture for its upcoming Windows Server 2003 release.
SuSE has promised a full 64-bit version of Linux as soon as the Opteron ships, with Red Hat committed to follow a bit later. IBM is promising new servers based on Opteron technology. Even Sun Microsystems is reportedly ready to use Opterons in its blade servers (define).
Sun’s already has a 64-bit processor in use — the UltraSPARC. Other 64-bit product brands already available include Hewlett-Packard’s PA RISC and Alpha chips as well as and IBM’s PowerPC processors.
Many smaller vendors have licensed designs from Newisys, an Austin, Texas, startup headed by former IBM and Dell execs that’s offering a complete dual-processor 1U rackmount server, configurable with 512MB to 16GB of DDR333, paired Ultra320 SCSI or IDE hard drives, dual embedded Gigabit Ethernet adapters, and two PCI-X expansion slots.
No one denies that AMD faces an uphill fight against Intel, but there has never been so much buzz surrounding an AMD server processor, nor such promise for truly competitive performance and scalability — both for entry-level and midrange servers, and for four- and eight-way systems in the $10,000-and-up segment that today’s Athlon MP has had to cede to Intel’s Xeon MP and Itanium 2.