Here's a collection of the most frequently asked BIOS related questions we get.
- What is a BIOS?
- I'm getting the message "CPU is unworkable or has been changed." with every setting I try on my Abit motherboard. What's wrong?
- What does the setting "L2 Cache Latency" mean, and is it better to set it to a higher value?
- Should I always upgrade/flash my BIOS whenever there's a new version available from the manufacturer?
- I have changed a setting in my BIOS, and now my system won't boot. How do I change the setting back to what it was before, when I can't even get into the BIOS?
What is a BIOS?
The BIOS (stands for "Basic
Input and Output System") is a small program
that manages you computers hardware. It has various function, which include:
initializing and testing your hardware when the system is powered on (called
"Power On Self Test" or "POST" for short), making a link
between the OS (operating system) and your hardware, and it allows you to make simple
configuration changes to your hardware.
It is not a place for beginners to play around, so if you are uncertain about some of the settings in there, LEAVE THEM ALONE!
Most of the modern motherboards also use the BIOS for configuring the working frequency of your CPU, and therefore provides an easy method of overclocking the CPU.
Before entering the BIOS, you
should read the motherboard manual thoroughly, and only change the settings you
are certain of the meaning of.
I'm getting the message "CPU is unworkable or has been changed." with every setting I try on my Abit motherboard. What's wrong?
The problem is that Abit (by reasons unknown to us) has included an option in their Soft Menu called "Speed Error Hold". This option halts the system, if the speed is not set at default. This means that if you intent to overclock your CPU, you should disable this option. In short, set "Speed Error Hold" to "Disabled" and it should work.
What does the setting "L2 Cache Latency" mean, and is it better to set it to a higher value?
The L2 Cache Latency setting
allows you to set the latency the Level2 Cache on your CPU should be working
with. The lower the Latency, the faster your Level2 Cache will perform, but the
difference in performance is somewhat negligible, and might give you an unstable
It can be a good tool of providing the last bit of stability when overclocking your CPU, but it's seldom enough to make a big difference.
Some motherboards (some Abit boards and possibly other brands too) have a fault in the L2 Cache Latency adjustment, that disables the L2 Cache completely when set to 8 or above. This has a massive negative influence on the performance of your system, so beware if your board has that flaw.
Should I always upgrade/flash my BIOS whenever there's a new version available from the manufacturer?
No! Since the procedure of
flashing/upgrading a BIOS is a somewhat risky operation, you should only
upgrade/flash when the new BIOS supports a function that is needed for you. You
should also read the manufacturers instructions thoroughly before starting the
procedure, and under no circumstances reset or power off the system before the
procedure is complete.
So if you are not missing a feature that's supported in a newer BIOS release don't upgrade (don't fix it if it isn't broken)
I have changed a setting in my BIOS, and now my system won't boot. How do I change the setting back to what it was before, when I can't even get into the BIOS?
Most motherboards have a
jumper on the board itself, that allows you to reset the BIOS to it's default
values. Some of the never boards also have the ability to reset the BIOS by
holding down a key (on the keyboard) while powering on the system. Read the
motherboard manual for instructions on how to do it with your board.
If the manual doesn't mention how it's done, you can always take the battery out of the motherboard (be careful not to leave grease marks on the battery), keep it out for a minute or so, and reseat it in it's socket. This should erase the CMOS (the device that is storing the BIOS settings) and reset the BIOS to it's default values!
More to come...