My effort to explain what the setting in your BIOS do.

Examples in "Olive" are based on my current rig.

Processor: 2400+ (unlocked) w/SP-97
Motherboard: NF7-S Rev.2
RAM: Generic Samsung 2x512 Pc3200(400MHz)
Video Card: Radeon 9800Pro


//CPU MENU//

CPU Operating SpeedUser Defined
This option lets you select the actual operating speed "2400+" or "user defined" which allows you to change External Clock and Multiplier Factor.

External Clock205
This setting controls the clock speed of the memory bus on the motherboard. The internal processor speed is the product of the "External Clock" x "Multiplier Factor" = 2537MHz

Multiplier Factor11.5
This setting controls the multiplier that is used to determine the "Actual clock speed" of the processor relative to the external or motherboard clock speed. "External Clock" x "Multiplier Factor" = 2537MHz

CPU FSB/DRAM ratio3/3
How your RAM interacts with your "External clock"

External Clock = 200MHz
Divider 3/3
RAM = 200MHz(400MHz Effective)


External Clock = 133MHz
Divider 4/6
RAM = 200MHz(400MHz Effective)

CPU Interfaceenabled
This setting just increases the FSB speed, however it's pointless as you should already have the option to set the FSB to whatever you want. (Googled not sure if true)

//VOLTAGE MENU//

CPU Core voltage or Vcore2.03
This setting controls the amount of voltage going into your cpu. Note that you shouldn't raise this too high unless your cooling is up to the task as it CAN damage your CPU.

DDR SDRAM Voltage2.9
This setting controls the amount of voltage going into your RAM.

Chipset Voltage1.7
This allows you to change the "chipset voltage" or the "northbridge" (nForce 2 Ultra 400) this usually allows you to get higher overclocks.

AGP Voltage1.5
This is the voltage going into your video card, raising this will do nothing to help you obtain higher overclocks. And may damage your card. Unless otherwise posted, keep this at 1.5 as the extra power is drawn from the "external molex connector" (9800Pro).

//AGP/PCI-E Menu//

Init Display FirstAGP
This BIOS feature allows you to select whether to boot the system using the AGP graphics card or the PCI graphics card.

AGP Aperature Size128MB
This is when you run out of Video RAM, it then allocates RAM from the windows 4 GB memory address space.

AGP Frequency66MHz
This should be kept at 66MHz to keep from frying your video card. But even very small changes cause severe system errors, destabilization etc.

AGP Data Transfer Rate8x
The Accelerated Graphics Port operates at a clock speed of 66 MHz, but allows for a variety of high transfer rates, depending on the specific mode of operation. AGP currently allows for transfer rates of 1x, 2x, 3x, 4x, or 8x. Any newer AGP card should be set 8x if the BIOS doesnt automatically do it. Older cards will operate at a 4x interface.

AGP Fast Write Capabilityenabled
Fast Write allows the AGP device act like a PCI device. This allows it to bypass the main memory and directly access the data which improves AGP read performance. However AGP write performance is not affected. You should turn this on.

PEG Link Mode.
PEG Link Mode stands for PCI Express Graphics Link Mode, nothing much is known about it.


//BIOS MENU//

System BIOS Cacheabledisabled
On most systems, you can shadow your system BIOS ROM. Caching of the motherboard BIOS ROM from F0000h to FFFFFh by the processor's Level 2 cache. This greatly speeds up accesses to the BIOS. This
is a waste of the Level 2 cache's bandwidth. I recomend to disabled it.

Video RAM Cacheabledisabled
This like the "System BIOS Cacheable" will use the processor's L2 cache. With the VIdeo RAM to cache that small 64KB region of the video RAM. The performance of the graphics card will most probably receive a boost from the lower latency and higher bandwidth of the processor's L2 cache. Again this is a waste of the Level 2 cache's bandwidth. I recomend to disabled it.

FSB/AGP Spread Spectrumdisabled
This option is to eneable modulating of the signal it generates so that the spikes are reduced to flatter curves. Usually offers two levels of modulation - 0.5% or 1.0%. System stability may be compromised and I recommend that you disable this feature.

Quick Power on Seld Test/ Quick Boot
Enabling this setting will cause the BIOS power-on self test routine to skip some of its tests during bootup. One of the key things this setting usually does when enabled is cause the POST to skip checking all of extended memory for errors.

Boot up Floppy Seekdisabled
This BIOS feature determines whether the BIOS checks for a floppy drive during boot-up or not.

Security OptionSetup
The ability to have the BIOS password protected.

//HARDWARE MONITOR//

CPU Thermal throttlingdisabled
CPU Throttling occurs when the CPU becomes 'too hot'. The CPU throttles down the load to decrease it's core temperature. The default setting is usually 62.5%or 50.0%.I turn this off as I know my cooling is fine.

CPU Disconnect Functiondisabled
A far as I know this drops the CPU temperature during idle time and possibly lowers the energy used but I don't recommend it because it may make the system unstable when overclocked. If you have good cooling don't use it

//MEMORY//



Memory Timing Settings
The memory's real speed is determined by the timing that the system is told to use, often via settings in the BIOS setup program. These settings control how quickly the system will try to read or write to the memory.

CAS (Column Access Strobe)
A signal which tells the DRAM to accept an address as the column address. Used in conjunction with Row Access Strobe (see RAS) to select a bit of DRAM.

CAS Latency
CAS latency refers to the ratio between column access time and clock cycle time. Since column access time refers to the period after the CPU requests a column, to when the data is moved to the output line, a lower CAS latency means less clock cycles to move the data to the output line. It is usually recommended you use the lowest CAS latency which your RAM and motherboard can run stable with.

Tras (Active to Precharge)
Tras specifies the amount of time required between an active command to a precharge command. Basically this means the number of cycles that must pass after a bank is opened to when it can be closed. It is usually recommended you use the lowest Tras which your RAM and motherboard can run stable with.

RAS# to CAS#
This is the delay in memory cycles between the time a row is activated and when a column of data within the row can actually be requested.

RAS Precharge
This is the time in memory cycles that is required to flush an active row out before a new row can be requested. This only comes into play when a request is made to an inactive row.

Command Per Clock [ON/OFF]
Dram Timing [1T/2T]

So far I am conviced these are the same things, you will hear alot about the diffrences between the two.

In most cases it comes down to that you should have the cpc OFF(2T) for dual sided ram, and ON(1T) for single sided ram.

1T has more performance, but is usually suited for "the best" ram that can handle this timming, 2T should almost always be used and normally alows for higher FSB, it also work with any RAM.

I suggest 2T unless you really know your hardware.

Anyhoo, hope this helps.

Great write up man. That should explain alot of things to some of the newer members around here. This should be stickied

Quote: Originally Posted by Cpt.Planet Great write up man. That should explain alot of things to some of the newer members around here. This should be stickied

I agree. It made a lot of sense to me and helped me understand some of the options I've tried looking up but found too confusing to understand. By the way, bling to you for that

Thanks guys, Im learning what some of this stuff does too. I want to add alot more about IDE settings. But that stuff seems confusing.

Nice work.

i have been learning about how to build my new PC and working to pay for it.
There has been little time for the BIOS research.

Thanks this post has helped a lot.

If anyone can give me some info on RAM timmings I will rep you for and and make sure your work is credited when I add it into the post.

Updated with more information about ram timmings, plus a bump

This is similar to theups' "Terms" thread.

Everyone is so nice and helpful here

awsome guide tycoon.if you ever get a chance to have a look at a gigabyte k8ns ultra-939 i would be
interested in some of the settings eg-cpu clock ratio
-ht frequency
-ht-link voltage control just to name a few

Im looking for imformation pertaining to newer socket 939 motherboards to add to this, in a simple easy to understand form. I would rather not rip-off other peoples stuff(a couple of nerco'sthreads would be usefull).

Becuase, well I dont have any of this new stuff. And I would like to keep this updated. Please PM me with any advice/stuff I can add, you will be credited.

Quote: Originally Posted by TYCOON Im looking for imformation pertaining to newer socket 939 motherboards to add to this, in a simple easy to understand form. I would rather not rip-off other peoples stuff(a couple of nerco'sthreads would be usefull). Becuase, well I dont have any of this new stuff. And I would like to keep this updated. Please PM me with any advice/stuff I can add, you will be credited.

you are welcome to anything in a thread i started for the k8ns ultra-939 gigabyte board.'solid ' added a few good pointers. - http://forums.pcapex.com/showthread....183#post409183
any thing to help out.

This write-up needs to be stuck Nice job Tycoon. You have bling. Im glad someone has posted this info...Some of the settings in your BIOS can be a bit confusing.

Does anyone know what the PEG options, like PEG Root Control and PEG Buffer Length, do?

http://www.rojakpot.com/default.aspx...ar1=130&var2=0

No one nows man

Your AGP Aperture size is the amount of system memory the video card is allowed to use if needed. Unlike an "On-Board" video chip which actually allocate's the amount selected. It is recommended to set your AGP aperture to 1/2 your system ram. Newer cards seldom need to use the setting but it doesn't hurt to have it if needed.

Quote: Originally Posted by Hibiki Does anyone know what the PEG options, like PEG Root Control and PEG Buffer Length, do?

PEG= PCI-Express Graphics. Here is a link about it. All I could Google on it in a hurry...Sorry.

Edit: Tycoon beat me, LOL. Same link

no sir still dont get the whole OC thing, oh well in still here