BIOS Setup

Introduction
In this web page we explain some advanced settings for the newest BIOS used by new generation computers.

Links

 * BIOS for Beginners (Tom's Hardware)
 * The Definitive BIOS Optimization Guide

What is the ideal cpu temperature?
Use the table below for the newest Intel processors:

Scale 2: Quad Q9x50: Tcase Max 71c, Stepping C1, TDP 95W, Idle 16W Q9300: Tcase Max 71c, Stepping M1, TDP 95W, Idle 16W Q6x00: Tcase Max 71c, Stepping G0, TDP 95W, Idle 16W -Tcase/Tjunction- --70--/--75--75--75--75-- Hot --65--/--70--70--70--70-- Warm --60--/--65--65--65--65-- Safe --25--/--30--30--30--30-- Cool Tcase = CPU temperature Tjunction = Core temperatures

Spread Spectrum
If you do not have any EMI problem, leave the setting at Disabled for optimal system stability and performance.

The Spead Spectrum function reduces the EMI (Electromagnetic Interference) generated by modulating the pulses so that the spikes of the pulses are reduced to flatter curves.

However, while enabling Spread Spectrum decreases EMI, system stability and performance may be slightly compromised. This may be especially true with timing-critical devices like clock-sensitive SCSI devices.

Enhanced Halt State
Set it to Enabled.

Enhanced Halt State (C1E) Reduces Clock Speed when needed. The operating system will send the HALT command when there is nothing to do, lowering thermal loss considerably.

No-Execute Memory Protection
Set it to Enabled.

Also known as the NX bit, which stands for No eXecute. Intel refers normally also to the XD bit, for eXecute Disable. AMD uses the name Enhanced Virus Protection. The ARM architecture refers to the feature as XN for eXecute Never.

An operating system with support for the NX bit may mark certain areas of memory as non-executable. The processor will then refuse to execute any code residing in these areas of memory. The general technique, known as executable space protection, is used to prevent certain types of malicious software from taking over computers by inserting their code into another program's data storage area and running their own code from within this section; this is known as a buffer overflow attack.

Onboard Serial Port
Set it to Disabled.

Most people no longer use serial ports for connecting external peripherals, as most have been replaced by USB equivalents. If you do not use the system's serial ports, disable the ports and free up the resources. On the other hand, if you do use the serial port, then this option should be set to 3F8/IRQ4.

Onboard Parallel Port
Set it to Disabled.

This setting lets you decide whether to select parallel port mode resources or disable the parallel port completely. If you have nothing plugged into the parallel port, disabling it will free up valuable system resources. But if you use the parallel port, then I recommend you set it to 378/IRQ7.

Parallel Port Mode
Set it to Disabled or 378/IRQ7.

If you have disabled the parallel port, then this setting is irrelevant. However, if the parallel port is enabled, you should configure it to run in EPP (enhanced parallel port) or ECP (enhanced capabilities port) mode. EPP mode is recommended if the system has just one device, such as a printer, plugged into its parallel port. Select ECP if you have daisy-chained more than one device - such as an external Zip drive, scanner, printer, or tape drive - to the system's parallel port. To take full advantage of these settings, make sure you're using IEEE-1284-compliant parallel cables.

PCI Latency Timer
Set it to 32.

This BIOS feature controls how long a PCI device can hold the PCI bus before another takes over. The longer the latency, the longer the PCI device can retain control of the bus before handing it over to another PCI device.

Normally, the PCI Latency Timer is set to 32 cycles. This means the active PCI device has to complete its transactions within 32 clock cycles or hand it over to the next PCI device.

ACPI Suspend to RAM
Set it to Auto.

ACPI stands for Advanced Configuration and Power Interface - not to be confused with APIC or IPCA, which some people may find as options in their BIOS setup programs. The Suspend to RAM feature, sometimes referred to as S3/STR, lets the PC save more power when in Standby mode, but all devices within or attached to the computer must be ACPI-compliant. Some BIOS's offer an S1/POS option for this scenario. If you enable this feature and experience problems with the standby mode, simply go back into the BIOS and disable it.

ACPI HPET Table
Set it to Enabled.

HPET stands for High Precision Event Timer and was developed jointly by Intel and Microsoft. An HPET block consists of a fixed-rate up-counter and 3 to 32 independent timers, each of which consists of a comparator and a register for storing a trigger value. There can be at most 8 HPET blocks. Each comparator can generate an interrupt when the counter reaches a pre-programmed value.