Specifications for AMD's 64-Bit Sledgehammer
As of today, AMD offers the specifications for the processor architecture x86-64 for the 64-bit processor (code name: Sledgehammer). It seems that AMD is building on Intel's 128-bit Streaming SIMD Extension (SSE) and of course the 3DNow extension.
It is not certain whether the SSE version is that of the Pentium III or the Pentium 4. AMD builds three different operating modes into the 'Hammer', the reason for this is the downward compatibility intended by AMD:
- 64-bit mode in 64-bit operating system
- 32 -Bit mode (Compatibility Mode) in 64-bit operating system
- 32-bit mode (Legacy Mode) in 32-bit operating system
Intel, however, is based on a pure 64-bit architecture that cannot cope with 32-bit software or only with considerable loss of performance. AMD's operating modes should ensure that the OS is recognized and the mode is then switched to 32 or 64 bit.