Remember when I told you to make sure you knew where the CMOS Reset was for your motherboard? Well, this is your last chance. The following section will begin taking you into the very depths of the system board. A certain amount of care is required while delving into the very heart of your system, but with a little common sense and the aid of this guide, we should be able to get your system performing at it's very best in no time at all.
The motherboard that I use is based on the Award BIOS so it may not be identical to yours. Even so, the settings and meanings are universal for the most part so should still be helpful in determining the values needed for your personal rig.
Hint: It is recommended that you change only one or two settings at a time and then reboot and look for stability within the system. This way you will know what settings are the cause of any problems that might crop up.
- Advanced BIOS Features
There isn't too much in this area to worry about, but it is a good idea to double check that ECC Checking is off and that both Cache settings are enabled. This will ensure that you are using the cache built into the processor and also any that may be onboard the mainboard itself. Unlikely, but possible.
The ECC should be turned off because even if you have a board that supports error correction, the use of ECC adds an extra wait state to your memory speed. While this can be extremely useful in a business database environment, it simply slows down your memory in a performance machine. From an enthusiast standpoint, it is better to just stay away from the ECC modules. Besides, they cost more to boot.
- Advanced Chipset Features
Again, we are looking at the Award BIOS here. If yours does not look exactly the same, don't worry. Your settings will just be located in a header with a different label.
DRAM Clock/Drive Control
Under the DRAM Clock header, we'll find the option of setting our system to a base 100MHz FSB or a base 133MHz FSB. This particular board uses the VIA KT266A chipset, so these are the only choices. If you happen to use a mainboard that uses the VIA KT133 chipset, then you probably will not have these two options as this chipset didn't support the 133MHz speeds. On the other hand, if you happen to have a shiny new KT400 chipset in your board, then you may even have additional settings for 166MHz FSB settings.
For our example here, we will set the value to 133MHz. This will give us the best possible range of speed settings when overclocking and a vast majority of the old Thunderbird processors will run smoothly at 133MHz anyway.
The next setting that we'll look at here is the DRAM Timing. This is where you can adjust the CAS (or latency) of your memory. I won't try to get into a long-winded explanation of CAS definitions, so let's just put it in simple terms. The CAS timings are basically the number of steps required for memory to perform its function. The higher the CAS setting, the slower the memory speed because it has more steps to follow before it completes the task. Simplistic, but this should suffice to show that lower is better.
Generally, the default setting here will be a value of "3". Since we want things to run as quickly as possible, we'll want to make a change here. Standard PC2100 DDR memory will usually be rated at CAS2.5 while older PC133 SDRAM will be rated at either CAS3 or CAS2. Regardless of which memory you use in your system, set this value to "2" for a trial run. Unless you have bargain basement memory modules, it will likely perform very well at the faster speeds.
Hint: When you start boosting the processor speeds to higher levels, this can be an area to turn back to "2.5" or "3" values to attempt to gain higher FSB stability. Since raising the FSB also raises the speed of the memory, this will sometimes be the cause of crashes. When you first start locking up during your FSB raising venture, try setting this back a notch and try that same FSB again. Since different systems perform differently, you will need to benchmark both settings to see if the slower memory speed coupled with the higher overall system speed makes it worth your while.
Also connected to this setting is the Bank Interleave. Unless your PC is truly ancient, you'll want to set this value to "4 Bank". Commonly referred to as 4-way Interleaving, this is a technique that creates an increase of the memory bandwidth by allowing the memory to access more than a single chunk of memory at one time. Try the 4-way setting first and then back off if required.
DRAM CMD settings
This particular section of the BIOS is one that will require the greatest amount of trial, error and patience. These settings cover things like memory precharge times, RAS pulse widths and delay timings. Or, if you're not feeling all that patient, you can go back up to the top setting on this screen and choose "Turbo" for the System Performance tag. But then that really takes all the fun out of the process, doesn't it?
AGP & P2P Bridge Control
This area allows you to make adjustments to the AGP settings. Without certain settings being made in the BIOS, you won't be able to access your video cards' full capabilities. The first choice is the Aperture Size. After countless debates on the topic, it has generally been agreed upon that a setting of 128MB will provide you with optimal results.
Next is AGP Mode. If you have a video card that supports AGP 4x and you have a motherboard that also supports AGP 4x, then the setting here should be obvious. If you happen to have a video card that only supports 2x AGP mode, then set it as such here. Otherwise you can look forward to some very possible conflicts between the motherboard, the video card and your choice of drivers.
AGP Driving Control is next up and should just be left on the "Auto" setting unless you are having some incompatibilities that point to this setting. Playing with this setting too much can easily (and probably) result in some hardcore system crashes.
The AGP Fast Write setting is a personal choice. This is another one of those areas that folks will argue over all day long. The end result is this...While Fast Writes have shown to provide a little higher performance, the gains are minimal. Though not a bad thing, the use of this setting has been known to cause system instabilities in a rather large number of systems. You'll have to play with this one on your own and determine if it is worth the effort in your system. If it causes lockups or video errors, then disable it.
The final two settings under this header are labeled "AGP Master 1 WS Write" and "AGP Master 1 WS Read". By default, your AGP will wait for two cycles before accessing the video board. By enabling these settings, you are reducing this to a value of "1", so are enhancing the performance of the video board. If you discover any instabilities after enabling this feature, then just change it back to the default "Disabled" setting for the sake of stablity.
The remainder of the settings under the Advanced Chipset Features may be left at default settings. There isn't anything else in these areas that will make any real difference to our performance, so we won't play with them.