The ‘No Execute’ Feature in AMD Sempron

The AMD Sempron is a line of CPUs that use different technologies and CPU sockets and that have replaced the AMD Duron processors and competes with the Celeron series of processors from Intel. The first of the AMD Sempron processors was based on the Athlon XP architecture and had a Socket A interface and a 166MHz Front side bus. Its L2 cache was 256 Kilobytes. The Thorton CPU had an L2 cache of 512 KB that was disabled but could be reactivated by a slight modification to the chip. Apart from a few differences, the AMD Sempron CPUs and the Athlon 64 CPUs were essentially identical in their architecture, power and features as can be seen in their similarity of having an integrated on-die memory controller, the use of the Hyper Transport link and the addition of the ‘NX bit’ AMD feature.

The AMD Sempron technology uses the AMD64 technology core to offer leading edge performance for both the 32-bit and the 64-bit computing platforms with the 64-bit offering additional computing performance over the previous 32-bit generation. The chip also comes with an enhanced virus protection capability with the added ‘No Execute’ feature that is supported by the Data Execution Protection (DEP) technology on Microsoft XP SP2 and Vista operating systems. This Data Execution Protection feature is supported by having buffer overflow memory locations restricted for any executable code. Running code from these locations allows attackers to control the computer by either loading a virus from different location or other attack instructions. The fact that there are more developed tools for creating sophisticated attacks are available means that network management and security should likewise be given higher priority and the ‘No Execute’ feature takes security measures to the hardware level.

The complexity of networked application architectures also continues to increase and as platforms such as .Net, J2EE and Web Services continue to grow in popularity, the need for flexible support that can be easily integrated into business processes becomes increasingly important. The AMD Sempron line of processors offers such a comprehensive approach by offering, not just server security solutions, but also desktop security solutions from where most of the security breaches originate. In addition, to the above, online transactions continue to grow rapidly and many enterprises will continue to automate their business processes across connected remote computers. A single vulnerability to such systems can thus result in high losses. AMD Sempron solution of DEP will thus go a long way in offering the extra security necessary to contain any sophisticated malware that takes advantage of hardware vulnerabilities.