Physical Architecture

Like other Athlon XP models, the Athlon XP sticks with the enhanced Palomino core and does not represent a move to the 0.13-micron Thoroughbred. Although the processor itself features a 2000+ rating, it runs at 1.67 GHz, rather than 2.0 GHz. We're starting to really move far beyond basic Athlon speeds and these newer Athlon XP processors are significantly faster even based on straight clock speed. The Palomino core also translates into enhancements such as SSE-support (through 3DNow! Professional!) and a Data Prefetch function that can speed CPU data transfers quite significantly.

The internal design of the Athlon XP 2000+ also remains unchanged from previous models, and features the same 128K of L1 cache and 256K of full-speed, on-die L2 cache as it predecessors. Before the release of the Pentium 4 Northwood, this cache level put the Athlon XP ahead of the Pentium 4, but today's comparison is a bit different. The Pentium 4-2.0A and 2.2 GHz models now include a full 512K of L2 cache, or double that of the Athlon XP. Just how this impacts overall performance will be answered a bit later on, but obviously Intel has hit the ball back into AMD's court.

The other basic specs of the Athlon XP 2000+ also remain consistent. This new chip is only found in 266 MHz parts, has a 1.75V voltage requirement and runs on the current Socket A platform. In fact, our review Athlon XP 2000+ featured the exact same core revision and stepping as the Athlon XP 1900+ so overclockers shouldn't expect any added bonus with the new model. To help differentiate between the various Athlon XP model numbers, here's a chart outlining their true core speeds and clock multipliers.