AMD Confidential

User Manual

November 21st, 2008

A.5 Known Issues

A.5.1 FSAVE/FRSTOR and FSTENV/FLDENV

When the simulator is executing FSAVE/FRSTOR and FSTENV/FLDENV in real-mode it is using the 16-bit protected-mode memory format.

A.5.2 Triple Faulting

If the processor encounters an exception while trying to invoke the double fault (#DF) exception handler, a triple fault exception occurs. This can rarely occur, but is possible. For example, if the invocation of a double fault exception causes the stack to overflow, then this would cause a triple fault. When this happens, the CPU will triple fault and cause a shutdown-cycle to occur. This special cycle should be interpreted by the motherboard hardware, which then pulls RESET, which ultimately resets the CPU and the computer.

However, the simulator does not simulate triple faults. In case a triple fault occurs, the simulator stops the simulation. The simulation cannot be restarted until a reset is asserted but the simulation state can be inspected with the simulator‟s debugger.

A.5.3 Performance-Monitoring Counter Extensions

Setting CR4.PCE (bit 8) to 1 allows software running at any privilege level to use the RDPMC instruction. Software uses the RDPMC instruction to read the four performance- monitoring MSRs, PerfCTR[3:0]. Clearing PCE to 0 allows only the most-privileged software (CPL=0) to use the RDPMC instruction.

The simulator does support the RDPMC instruction but there is no logic behind the simulated performance counter MSRs.

A.5.4 Microcode Patching

Microcode patches do not affect the simulated machine behavior. This may have unintended consequences.

A.5.5 Instruction Coherency

Instruction coherency does not work when code pages have multiple virtual-mappings. Here is an example that would not work right:

1.There is an x86 physical page that has code on it.

2.This page is mapped by two different virtual addresses, A and B

3.There is a store to virtual page A

4.We execute code from page B

5.We store again to A, modifying some of the x86 code that we executed in step 4

6.We execute the code from step 4 again

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Appendix A

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AMD 4.4.5 user manual Known Issues
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4.4.5 specifications

AMD 4.4.5 is a robust version of the AMD software ecosystem that focuses on enhanced performance, stability, and efficiency for users relying on AMD processors and graphics cards. This iteration brings various features and technologies designed to optimize gaming, professional applications, and general computing tasks.

One of the standout enhancements in AMD 4.4.5 is the integration of Smart Access Memory technology, which allows the CPU to access the full graphics memory directly. This feature enhances data flow between the CPU and GPU, leading to improved frame rates and overall performance, especially in memory-intensive games. Users can experience a marked increase in gaming performance without the need for additional hardware upgrades.

Another significant feature introduced is the updated Radeon Software Adrenalin Edition. This software update encompasses optimizations for various games, ensuring that gamers can enjoy a seamless experience with the latest titles. The Adrenalin interface also provides features such as Radeon Chill, which helps reduce power consumption during less demanding scenes, and Radeon Anti-Lag, designed to minimize input lag and enhance responsiveness in competitive gaming.

Additionally, AMD 4.4.5 brings the latest drivers that include important performance enhancements and bug fixes that allow for greater system stability. Regular updates ensure that users have the best experience with their AMD hardware, and it significantly bolsters compatibility with the latest gaming titles and software applications.

AMD's Enhanced Sync technology offers users the ability to eliminate screen tearing and stuttering while delivering smooth gameplay. It dynamically synchronizes the refresh rate of the display with the frame rates produced by the GPU, improving the visual experience significantly.

With the introduction of FidelityFX Super Resolution, AMD continues to bolster its suite of technologies that enhance graphics quality and performance. This feature allows lower-resolution images to be upscaled effectively, making it easier for users to enjoy high-end visuals without taxing their hardware excessively.

In summary, AMD 4.4.5 represents a comprehensive update for users by integrating cutting-edge technologies that cater to a wide range of applications from gaming to content creation. With enhancements across the board, AMD reaffirms its commitment to providing high-performance solutions that keep pace with the ever-evolving technology landscape. Whether for gaming aficionados or professional creators, the capabilities offered in this version make it a significant milestone in the AMD software ecosystem.
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