The SoftMenu TM BIOS Feature


The SoftMenu BIOS feature is at present only found on new ABIT and some QDI boards (so I've heard). It offers the convenience of an almost 'jumperless' board design and gives you the comfort to adjust and change your CPU settings without opening the computer case. You just enter your BIOS setup and do it from there via the software.

Under normal circumstances this mainly is a benefit for computer stores, who don't have to fiddle around with jumpers or dip switches anymore, when building complete systems for customers. The normal computer user usually only has to make the adjustments once, after plugging in his CPU and hence could do it via the good old jumpers or dip switches for that only one time just as well.

However, for the performance hungry visitors of my website this is the perfect way to tweak the system performance from the comfort of your chair. You even can run Quake at higher settings as Windows95, which wouldn't run at the same settings, without ever opening your computer case.

Now What Is The SoftMenu Able To Do In Particular And How Does It Work?

After installing your SoftMenu board, you won't have to change any jumpers or dip switches before you switch on your computer for the first time. Just plug in your CPU, your PCI and ISA cards, your HDD, floppy and port connectors and you're ready to go.

You start your system and the display will show you, that your CPU is running at the slowest settings, which is 75 MHz CPU clock for an Intel Pentium CPU.

Now you enter the BIOS setup and in the BIOS main menu you will find a new and unusual first menu selection, called '! ! CPU SOFT MENU ! !' .

After entering the CPU SOFT MENU you will see, that the BIOS has already automatically recognized the CPU type you are using. The actual ABIT SoftMenu is able to recognise the following CPU types:

  • Intel Pentium Classic
  • Intel Pentium MMX
  • AMD K5
  • AMD K6
  • Cyrix 6x86
  • Cyrix 6x86L (new split voltage type)
  • Cyrix M2

In the next line, you can choose from all the officially possible CPU speeds for the not advanced users, so it's extremely easy to do that. You can choose from:

Swipe to scroll horizontally
Intel Pentium Classicand MMXAMD K5Cyrix/IBM 6x86and 6x86L
75 MHz (1.5 x 50 MHz)PR75 (1.5 x 50 MHz)P120+ (2 x 50 MHz)
90 MHz (1.5 x 60 MHz)PR 90 (1.5 x 60 MHz)P133+ (2 x 55 MHz)
100 MHz (1.5 x 66 MHz)PR 100 (1.5 x 66 MHz)P150+ (2 x 60 MHz)
120 MHz (2 x 60 MHz)PR 120 (1.5 x 60 MHz)P166+ (2 x 66 MHz)
133 MHz (2 x 66 MHz)PR 133 (1.5 x 66 MHz)P200+ (2 x 75 MHz)
150 MHz (2.5 x 60 MHz)Row 5 - Cell 1 Row 5 - Cell 2
166 MHz (2.5 x 66 MHz)Row 6 - Cell 1 Row 6 - Cell 2
200 MHz (3 x 66 MHz)Row 7 - Cell 1 Row 7 - Cell 2

In this case, you won't have to fiddle around with bus speed or multiplier settings, it's done automatically for you.

You also can choose 'User Define', which gives you the option to select the bus speed and the multiplier yourself, as long as you are confident about doing that. If you should choose 66 MHz for your bus speed, you also have got the option of enabling the 'turbo frequency' feature .

Unfortunately I couldn't choose 83 MHz bus speed on any of the ABIT boards I've tested, but you CAN choose 75 MHz bus speed, which isn't too bad either. The options are:

  • 50 MHz
  • 55 MHz
  • 60 MHz
  • 66 MHz (with or without 'turbo frequency' )
  • 75 MHz
  • The multiplier settings are next, in case you've choosen 'user define'. You can choose from
  • x 1.5
  • x 2
  • x 2.5
  • x 3
  • x 3.5 (only for Cyrix M2 CPU's, otherwise you can't choose this option)

The next setting you can change is the CPU voltage . Nowadays there are two different types of CPU supply voltages, the single voltage for all the current Pentium, K5 and 6x86 CPUs and the split voltage , for the new Pentium MMX, K6, 6x86L and M2 CPUs. The motherboard is able to auto-detect the correct voltage settings, so you don't have to fear, that you will fry your MMX CPU at 3.3 V. However, you are able to change it here. ABIT claims that you can't damage your CPU with these settings, because the board will detect and disable a dangerously high voltage setting. However I think you still should be cautious with these settings, especially with the new split voltage CPUs.

You've got 3 different options to choose your general voltage settings from.

  1. Via CPU marking enablres you to choose from all known CPU markings of your particular CPU type. Hence there must be a little database within the BIOS. This option is most convenient to unexperienced users. You only have to read your CPU markings.
  2. Single voltage means, that your CPU core is running at the same voltage as all the other board components as e.g. the chipset. At this setting you can choose
  3. 3.38 V = STD3.52 V = VRE3.60 V - the perfect overclocking voltage.
  4. Split voltage means, that your CPU core runs at a lower voltage as the rest of the motherboard. Options to choose from:
  5. 2.50 V2.70 V2.80 V2.93 V

Some of you may wonder what happens if you change your CPU. ABIT has three solutions for this condition, whch are more or less sensible.

  • the tough way of completely erasing your CMOS settings via the erase jumper on the M/B. This way ALL your previous settings will get lost and the board starts again at the lowest level CPU.
  • Before shutting down your system with the old CPU, adjusting to the slowest settings. This will keep all the data.
  • Switching the system on and off several times in a short time period. This only will reset the CPU SoftMenu of the BIOS to slowest settings. It actually also works with pressing RESET several times.
  • Tom's first article (published in 1996) gets a first comment!
    This is from the future, toms, in 13 years you'll look back on this article and smile! :-)
  • Shnur
    That is such a nice article... overclocking back in the 90s