What is Max CPUID value limit in BIOS?

Max CPUID Value Limit: This is mainly used for Intel Pentium 4 processors with HyperThreading technology. It allows higher level CPU ID values to be used like 03h (hexadecimal values). This only needs to be enabled if the operating system does not support specific features.

What is Max CPUID limit?

The maximum CPUID input value determines the values that the operating system can write to the CPUID’s EAX register to obtain information about the processor. Intel processors from the Pentium Pro onwards have a maximum CPUID input value of only 02h or 03h.

Should I disable execute disable bit?

This provides some protection against buffer overflow attacks. When disabled, the processor will not restrict code execution in any memory area. This makes the processor more vulnerable to buffer overflow attacks. If your processor does not support Execute Disable Bit, then this BIOS feature will have no effect.

What is Execute Disable Bit in BIOS?

An execute disable bit is an Intel hardware-based security component used in the central processing unit (CPU) to separate areas of a memory as storage of processor instructions or as storage of data. EDB classifies areas in memory where a code can execute or not execute.

Is there a maximum value for the CPUID?

The maximum CPUID input value determines the values that the operating system can write to the CPUID’s EAX register to obtain information about the processor. Intel processors from the Pentium Pro onwards have a maximum CPUID input value of only 02h or 03h. The only exception is the Intel Pentium 4 with Hyper-Threading Technology (HTT).

How to set maximum CPUID to 3 in Windows XP?

There is an option named “Limit Manximum CPUID to 3”, the default value is Disabled, and Windows starts up normally. When I set this option to Enabled, the Windows Xp starting up is very very slowly, about 5 mins.

When to enable or disable CPUID input value?

When disabled, the processor will return the actual maximum CPUID input value of the processor when queried. It is recommended that you leave it at the default setting of Disabled. You should only enable it if you intend to use a newer processor with an operating system that does not support it.

Is there a default setting for the CPUID?

You can always now change Limit CPUID Value to default setting (OFF) (> 3) & see what happens?