Replies to post #41163 on Advanced Micro Devices Inc (AMD)

[morrowinder]

NX bit incompatible with some drivers and applications:

This may explain why Service pack 2 has been delayed so much.

"Driver compatibility issues with data execution prevention mostly center on PAE mode-induced compatibility issues."

"The primary driver compatibility concern is running Physical Address Extension (PAE) mode on 32-bit systems. PAE mode enables processors to address greater than 4 gigabytes (GB) of memory. The primary difference between PAE memory paging and non-PAE memory paging schemes is the extra level of paging that is required in PAE mode (3 levels instead of 2)."

"A final DEP compatibility concern derives from systems with PAE mode enabled, even though they may not be designed for more than 4GB of physical RAM. Microsoft has noticed in testing some systems with processors that support the NX processor feature fail to boot or have other stability issues when the processor is running in PAE mode.

PAE mode is a requirement for leveraging the NX processor feature. Therefore, system designers and firmware engineers should be aware that even though the system’s chipset and firmware may not have been designed to support more than 4GB of physical RAM, the system may be running in PAE mode."





http://www.microsoft.com/technet/prodtechnol/winxppro/maintain/sp2mempr.mspx

[upc]

the "top 5" in what sense?

Here's a link for you: http://www.investorshub.com/boards/read_msg.asp?message_id=3390252

Why do you think Intel (and Transmeta) are scrambling to add NX? Why is Microsoft pushing it? I guess they're all wrong, and you know better? <ggg>

upc

[sgolds]

morrowinder, do you know what a buffer overflow virus is? Any of the ones you listed can be implemented as a buffer overflow as its mechanism to enter the machine. It is the most common method for transmitting a virus, it says nothing about whether it is a trojan, worm or macro virus.

The way an overflow works is that executable code is written to a code area by creating a data segment that overlaps the code segment (CS). Then it is run using the CS instead (can simply be a long jump).

You are confusing the delivery mechanism with the contents.