BIOS: Control Center For Enhanced Performance
Overclocking fans know where it’s at: To push state-of-the-art motherboards to their limit in conjunction with the CPU and memory, a touch of manual fine-tuning to the BIOS settings is called for. It often happens that one setting or the other proves to be too “progressive”, with the effect that the board does not boot up afterwards. If this happens, deleting the CMOS settings is frequently the only option available if the board does not automatically boot with the slow default values. However, most users require a fair amount of explanation to optimize the performance of their systems to the fullest. Understandably, quite a number of PC enthusiasts who deal with hardware on a daily basis tend to avoid tinkering with the BIOS settings.
Using the well-known motherboard Asus CUSL2 as an example, we will show you step by step how it is possible to speed up a relatively sluggish board with digressive settings (mostly also factory settings) by a fair amount. Our example is typical for most boards and is based on an Intel (Socket 370) or AMD platform (Socket 462). For the sake of completeness, we have also taken a look at the BIOS from the Asus P4T for the Intel Pentium 4 to briefly highlight the special features of the Rambus memory.
BIOS: Control Center For Enhanced Performance, Continued
Following the merger of Award and Phoenix, both the traditional Award BIOS and the Award BIOS with a Phoenix look are now available. AMI also supplies BIOS software, but this is extremely rare and found only in very few mainboards. Our experience shows that the BIOS from Award (with the Phoenix look) is not very user-friendly – unlike the traditional Award BIOS, which is very logically structured and simple to use.
The BIOS is located inside an EPROM chip, which in turn is accommodated in a socket on the mainboard. The picture shows a later variant of a chip that stores up to 512 KB.
This EPROM chip represents an even older model. It stores up to 256 KB BIOS data.
Both chips when removed: The future belongs to the smaller chip on the right. Technically speaking, it was possible to store up to 1 MB in the small chip.
Requirements For BIOS Tuning
Before we get down to the actual business, it is advisable to check whether or not the motherboard already has the latest BIOS version. To do this, the version shown in the bottom left-hand corner during boot-up should display the latest date. The best way to obtain the latest BIOS version is from the FTP server of the respective motherboard manufacturer.
On numerous motherboards, the BIOS is write-protected. This protection has to be disabled prior to burning, by jumpers on the motherboard, or in the BIOS itself.
Helpful Hints For Diagnosis: Port 80 Card
The pictures show two different port 80 cards. The model above is designed for an ISA slot, whereas the card below it fits into a PCI slot.
Some boards are equipped with an integral port 80 card.
The port 80 card can be a very helpful tool for tuning a motherboard. It costs only very little and basically displays the status on boot-up. If a computer hangs at a certain point while booting up, the port 80 card can give a good idea which component is responsible for the fault. For this reason, a port 80 card is an absolute must for every experienced hardcore overclocker and fans of system tuning. Otherwise, it can be very difficult to determine the exact cause if the PC crashes or hangs.
Memory Tuning: There’s 5% More Power In There!
You need to select this menu in the BIOS if the settings for the memory are to be changed.
Default settings for memory timing ex works: All the adjustments are made automatically and are read by the EEPROM of the memory module.
Most PCs are supplied with highly conservative factory settings for memory access, with the result that vast amounts of power are either squandered or lie dormant. In the following pictures, we show how it is possible to change the settings for memory timing step by step.
Before you can change the memory timing manually, the “User Define” option has to be set.
CAS Latency: Major Effect
The performance screw turned up a notch: CAS latency has a significant impact on the memory’s performance.
It is not merely the memory clock (whether 100 MHz or 133 MHz) that governs the memory performance. Rather, it is the CAS latency that provides a key indicator as to how fast the memory can be accessed (latency!). Most older or cheap memory modules can often only be operated in CL3 mode (CAS latency = 3). These memories mostly do not feature an EEPROM chip, which is read out from the motherboard’s BIOS. The EEPROM chip, which is found on every state-of-the-art memory module, is used for storing important data like CAS latency. Nevertheless, it is possible to access the memory with shorter latency cycles than the factory-defined ones. By way of illustration, it poses no problem for many CL3 modules (or CL 2.5 DDR-modules) to be operated with a CAS latency of 2. This operating mode does not work with all modules – trial and error is the only solution here.
The picture looks entirely different, however, if the BIOS reads out or interprets the data from the EEPROM incorrectly. In such cases, it can happen that a CL2 module (at 100 MHz or 133 MHz memory speed) is operated in CL3 mode, with the result that the performance drops by 5 percent or more.
CAS Latency: Major Effect, Continued
Useful information: A memory module at 133 MHz clock in CL2 mode is faster than an overclocked module operating at 150 MHz in CL3 mode!
The “SDRAM Cycle Time” also affects the memory performance.
Enabling the “All banks” option only produces a marginal change in performance.
The following pictures show the various features that can be adjusted in the BIOS’s “Chipset Functions” menu.
The “USWC” option enables the write cache of the video memory and produces slight performance increases in conjunction with state-of-the-art graphics cards.
AGP Mode: 4x Faster Than 2x
Huge impact on graphics performance: The AGP mode should always be set to “4x”.
The option that controls the transmission rate of the AGP bus is pretty self-explanatory. Logically, “4x” is faster than “2x”, even though few applications work by swapping out textures over the AGP bus.
Some boards allow you to change the priority of the PCI bus. The picture shows the BIOS of the latest version of the Asus CUSL2 mainboard.
AGP Mode: 4x Faster Than 2x, Continued
SDRAM Data Driving Mode: The “Strong” setting ensures higher memory performance and disables error correction routines.
Few boards feature this option. The “Auto” setting is best.
To enhance system stability, the “DRAM Interleave” setting should also remain set to “Auto”.
Special Functions With RDRAM (Rambus)
This picture shows the BIOS of the Asus P4T board with RDRAM support: It is possible to manually adjust the ratio between the front-side-bus and memory speed.
The “CPU Fast String” option is only found on motherboards with RDRAM memory.
Now that a number of motherboards with RDRAM memory (based on the Intel 850 chipset) have been launched on the market, we will explain some of the special functions of Rambus. Most boards with the Intel 850 chipset feature only very few “adjustable” functions in the BIOS – as seen in previous tests on numerous occasions. One exception is the Asus P4T, which supports quite a few performance-enhancing modifications. The picture at the top shows the “CPU Fast String” option, which optimises the performance of the Intel Pentium 4. The pictures below show further features.
Special Functions With RDRAM (Rambus), Continued
For maximum power, disable the FPU OPCODE compatible mode.
This picture shows the optimum setting.
More speed: RDRAM is automatically run faster if this switch is set to “Turbo”.
DOS Relic: Shadow Memory Addressing
Relic from the DOS era: The “Shadow Configuration” menu is no longer relevant today in Windows 98SE and Windows 2000.
Even today, all modern boards still incorporate functions that date back to the bygone DOS era. These include the menus found under the category of “Shadow Configuration”. Only those users who still work in the antiquated MS-DOS operating system should tamper with these settings. After all, with state-of-the-art operating systems such as Windows 98 SE and Windows 2000, these adjustments are managed by the system itself.
Beneficial: The “Video ROM BIOS Shadow” function should always be enabled.
More Speed: Progressive Settings Of The CPU
This BIOS menu allows you to set important parameters for the CPU. Important: The L1 cache should be enabled.
The settings for the CPU cache are among the most important functions of the BIOS. The processor’s L1 cache and L2 cache should always be enabled; otherwise a huge deal of power will be squandered. This is true of all PCs, and it’s one of the basic things the user should keep in mind. After all, there is no harm in checking these settings in the BIOS.
The same goes for the L2 cache.
Releasing The Brake – ECC Checking
Brake: The “ECC Checking” feature should always be disabled.
It is possible to boost performance by a whole 1 percent by disabling the “ECC Checking” switch in the BIOS. In doing so, the data flow is no longer permanently supplemented with a checksum, whose function costs additional time.
Some boards offer the “Optimal System Performance” function, which essentially implies fast memory timing.
The picture above shows a function that is not featured in all motherboards.
Optional Feature: Onboard Graphics
For boards featuring onboard graphics (e.g. Intel 815 chipset), a portion of the RAM is used as the graphics memory. The picture shows that 32 MB are used as graphics memory.
Boards with onboard graphics such as an Intel 815E chipset use a portion of the RAM for storing graphics data. To do this, however, the onboard graphics function must be enabled, as otherwise the external graphics card is addressed via the AGP port. When onboard graphics are used, it is possible to adjust the size of the graphics memory via the BIOS, with 32 MB constituting the maximum limit for boards currently available.
Disable: Unused Components
This menu has to be selected to display the components.
Onboard sound in the form of an AC’97 chip: Those users who have an external sound card should always switch off the sound on the mainboard.
The following pictures show extracts from the BIOS where unused components can be switched off, such as parallel or serial ports. Doing this saves resources and speeds up the boot-up routine. In addition, this procedure prevents conflicts with other devices.
A word about the AC’97 sound chip: This sound generator takes up a slight amount of CPU power and does not achieve the quality of a “proper” sound chip of a sound card.
Switch off any serial ports that are not required.
Disable: Unused Components, Continued
It is possible to change hex-addresses by selection.
Transfer mode of the parallel port: “ECP+EPP” is optimal.
Those users with an external sound card can disable the game port on the board without any worries.
Optimising AGP/PCI Access
Help when encountering problems with the sound card: Changing the “PCI Latency Timer” offers a remedy.
The “Chip Configuration” menu comprises numerous features. You should only change the “PCI Latency Timer” switch if you encounter problems with the PCI sound card.
Fast boot-up: Disabling the SCSI BIOS saves time during startup.
Optimising AGP/PCI access, Continued
The bare necessities: Using the USB ports takes up free interrupts as well as minor resources of the system performance.
Booting with two graphics cards: It is possible to switch between an AGP or PCI card.
For old ISA cards: Reserving special interrupts is only worthwhile for obsolete components with an ISA interface.
Performance Boost: Spread Spectrum Control
Performance boost: The “Spread Spectrum Control” function slows the system. It should always be disabled.
This feature helps boost performance slightly.
Spread Spectrum Control: This function is used for meeting the specifications when complying with the CE acceptance test. Enabling it leads to a noticeable deterioration in performance. That’s why it should always be disabled!
AGP: Swapping Out Textures
More speed: RDRAM is automatically operated faster by setting this switch to “Turbo”.
A thing or two worth knowing about the AGP: The “32 MB” setting is more than adequate, since virtually all programs manage the AGP size themselves. Under Windows 98 SE and Windows 2000, the graphics card driver regulates the AGP size anyway in conjunction with the operating system. Basically speaking, no performance enhancement is noticeable.
AGP Fast Write: 10 Percent Increase
Significantly more speed: Enabling the “Fast Write” option ups the graphic performance considerably.
Caution: Changing this parameter (AGP) can quickly result in an instable system.
This option has to be supported by the graphics card, otherwise problems may be encountered with older cards that do not support this feature. If you proceed to enable this option in the BIOS, it will cause the system to crash!
The second picture shows the “AGP Drive Strength” function, which, at best, is designed for experimentation freaks – but not for anything else!
Power Saving Functions: A Question Of Taste
The “Power Management” menu allows you to set power saving functions of the board and the individual components.
Disabled: Hardcore gamers and power freaks should disable the power saving functions.
Wake-up call: It is possible to “wake up” the system from any power saving mode by means of an external entry. You can set this function via the BIOS.
Power-saving functions are particularly important for office users who are concerned with reducing power consumption. Gamers should, however, disable all such functions so as to avoid the risk of a system crash following a “wake-up” procedure. Essentially, the saving potential is governed by the particular Suspend Mode selected (S0 to S3).
Summary: Power-saving functions are only useful for office PCs, whereas performance hungry users should prefer to contribute to the world’s greenhouse effect by turning off all power saving features.
Overclocking: Increasing The AGP/PCI And CPU Clock Rate
Overclocking: Increasing the FSB and memory speed to 166 MHz. However, problems may occur with individual devices.
The most distinctive increase in speed is achieved by overclocking. To this end, most mainboards offer a variety of methods via the BIOS: On the one hand, it is possible to increase the clock multiplier (on boards with Socket 462 for AMD Athlon), such that the processor runs with a higher clock rate. On the other hand, it is also possible to increase the front-side-bus and the memory speed, which also produces a vast boost in performance. Since Intel processors are equipped with a multiplier lock, the only way to raise the clock speed is by increasing the front-side-bus.
Summary: Enhanced Performance Through Targeted Fine-Tuning
The BIOS of every motherboard offers the best options for making a board faster. Using the Asus CUSL2 (board with Intel 815E chipset) as an example, we have shown the individual menus in detail to explain how it is possible to optimize the settings for memory, graphics, AGP/PCI and so on. More aggressive memory timing alone produces up to 5 percent more performance. Fine-tuning helps users to eke out a further 5 percent, provided that the board supports these features in the BIOS in the first place. There are numerous PC systems where the BIOS supports very few functions for influencing the system performance. As a general rule, motherboards from Abit, Asus, Gigabyte, Epox, Elitegroup and DFI offer excellent facilities for tuning. In any case, users should take a closer look at their BIOS and the functions available and compare these with our illustrations.
You will always find that a percentage of your system’s performance is unused! And you can always accelerate the boot-up procedure and eliminate any conflicts. We are always grateful to receive your suggestions and hear about your experiences!