BIOS Configuration


Oct 9, 2002
I've just rebuilt my system and I'd like know how to configure some of the more cryptic options in my CMOS Setup utility. So, here goes:

AMD Athlon XP 2000

Hard Disk Drive
Western Digital WD400JB

Video Card
PNY Verto GeForce4 Ti4200 with AGP 8x (NVIDIA)


Advanced Bios Setup

APIC Function - Enabled

MPS Table Version - 1.4

Hard Disk S.M.A.R.T. - Disabled
-I've heard that this can detect a cascading HD failure. In my experience, a SMART error usually appears when it's too late to recover *anything* from a drive. Does SMART affect performance? Is this an older standard that has been replaced by a more-modern technology?

Video BIOS Cacheable - Disabled
-My old books used to recommend shadowing any BIOS ROM. However, I think I've heard that it would be a waste of memory now that bus speeds are vastly improved. Opinions? Benchmarks? Please?

Advanced Chipset Features

System BIOS Cacheable - Disabled
-See comment from "Video BIOS Cacheable"

Video RAM Cacheable - Enabled
-I think that this has something to do with the integrated NVIDIA IGP/GPU. The BIOS description says nothing. Does this option reserve system memory for the integrated video chipset (which is not in-use)? Even if it automatically knows to not allocate memory, it might be a waste of resources to let it auto-detect. Am I wrong about the function of this option?

AGP Aperature Size - 128M
-Not sure how this affects performance. Is there really a reason to have this option?

Integrated Peripherals

Init Display First
-Does it make sense to leave PCI selected instead of AGP? I think that this option is only provided for emergency situations, when a PCI card is used as a replacement for a non-functioning AGP card/bus.

IDE Function Setup

Primary Master PIO
Primary Slave PIO
Primary Master UDMA
Primary Slave UDMA
IDE Prefetch Mode - Enabled
IDE DMA Transfer access - Disabled
^What to do with these? Why are these options available to the user?

IDE HDD Block Mode - Enabled
-This is another one that sounds like a legacy feature. How does this affect the performance of a modern drive?

Onboard Device

AC97 Audio - Auto
-The NVIDIA software seems to have full control of the audio in my system, including the analog connectors. What does AC97 audio have to do with this system?

MC97 Modem - Auto
-I have no modem connector on my motherboard, I do not use a modem, and I don't use the CNR slot. Is it wasting resources to leave "auto" selected instead of "disabled"? I don't see a modem in the WinXP Device Manager, so I assume that it is disabled.

SuperIO Device

Onboard FDC Controller - Disabled
-I don't have a floppy drive. Does it save resources to disable a legacy device like this? I would assume that most operating systems won't use the resources anyway. I'm not sure if the processor continually checks un-assigned IRQ's or not, so I'm not sure if it will help performance to disable the FDC.

UART Mode Select - Normal
-Just wondering about this one. I know what the UART chipset does; but what does the "ASKIR" mode do?

Parallel Port Mode - SPP
-I have some legacy hardware (2 different N64 RAM-based cartridge emulators for game backup and development, 1 Game Boy Flash-memory based cartridge writer for backup/development). These devices use different modes and are extremely picky. I don't have the ability to test (requires Win98), but does the ECP+SPP mode present any compatibility problems with bi-directional devices?

EPP Mode - 1.7
-What does this option do? How does it affect compatibility? Why is "1.7" the default value instead of "1.9"?

ECP Mode Use DMA - 3
-Other option is "1". Does it matter which DMA is used?

Power Managemen Setup

Sleep State - S1(POS)
-I'm not using an old hardware internally. Is there any reason to not set this option to "S3(STR)"?

Video Off Method - DPMS Support
-Other options are "Blank Screen" and "V/H SYNC+Blank". I assume that "V/H Synch + blank" is for displays that don't have any type of sleep mode. I'll just leave this option at "DPMS Support", which I assume is a power-management standard.

PnP/PCI Settings

PCI/VGA Palette Snoop - Disabled
-What is this used for? I that it is a legacy option.

PCI Slot1/4 IRQ Priority - Auto
PCI Slot2/5 IRQ Priority - Auto
PCI Slot3 IRQ Priority - Auto
^Huh? Is there any way to tweak performance by fiddling with this? It sounds like it would be a waste of time. Why are these options provided to the user?

Frequency/Voltage Control

AGP Clock Control - Default
_Value - 66

CPU Ratio - By H/W

CPU Vcore Select - By H/W
-Voltage, perhaps?

PCI Clock Auto Detect - Enabled
-Are there really different standard for PCI-bus timing?