Enthusiasts love to know which “core” their processor is based on. “Core” is the silicon chip version used inside the CPU. Even in some ads you may find a reference to which core the CPU uses. To the regular user the core reference looks like Greek, so we decided to post a quick guide to all Athlon 64 cores released to date.
| Core | Socket | L2 Cache | Manufacturing Process | SSE3 Instructions | Note |
| ClawHammer | Socket 754 or 939 | 1 MB | 130 nm | No | |
| NewCastle | Socket 754 or 939 | 512 KB | 130 nm | No | |
| Winchester | Socket 939 | 512 KB | 90 nm | No | |
| Venice | Socket 939 | 512 KB | 90 nm | Yes | Enhanced Memory Controller |
| San Diego | Socket 939 | 1 MB | 90 nm | Yes | Enhanced Memory Controller |
SSE3 instructions were first launched with Pentium 4 processor and are MMX-like instructions, created to accelerate multimedia applications.
About the memory controller, what happens is that Athlon 64 processors have a limitation. When four DDR400/PC3200 memory modules are installed on the system, they are accessed at 333 MHz and not at 400 MHz. This was corrected on Venice and San Diego cores: on CPUs based on these cores the processor accesses the four memory modules at 400 MHz.