Upgrading CPUs and BIOS, Part 2

As you probably know, BIOS stands for Basic Input-Output System. A PC's BIOS chip sets up internal parameters the computer must have before it can load the OS from its hard disk.

In general, I try to avoid BIOS updates. Any small increment of improved functionality is drastically offset by the potential downside, namely, that the motherboard won't be able to handle the new firmware, that the system won't revert back to the old firmware, or—worst of all—that the system will be turned into an unusable brick.

However, sometimes there is no alternative. After you've dropped a new CPU into a system, the system may not work, even with the recommended BIOS. For instance, after I had serious stability problems with my CPU/BIOS setup, I tried a number of BIOS settings and installer combinations. These problems took several days to solve. So it's best to avoid such stability problems. Simply spend a few minutes searching the Web to make sure your intended CPU/motherboard combination has been proven to work. But what if the information you've gotten on the Web is wrong, and the system you've upgraded still doesn't work? That's where this Recipe comes in.

In Part 1, I explained how I spent $45 for a processor that would go to waste if I didn't try something radical to make the system work. At the time, I had no reason to believe there was a compatibility problem between the motherboard and the CPU. The way a motherboard is upgraded to make them compatible with newer processes is usually a firmware upgrade, which makes the BIOS the obvious suspect. Further, the BIOS was the easiest thing I could modify without buying new components. And I'd already discounted the power-supply unit (PSU) size as a potential problem, because the voltages weren't sagging the way I'd expect them to if the CPU was overloading the PSU. The increased power consumption of the new processor was reducing voltages (+5, +12, +3.3) by tens of millivolts as measured by a DMM (PCChips site, a supplier of motherboards and PC peripherals, and looked up the BIOS for my 810LR motherboard. I found several BIOS firmware files for the 810LR, though with no information on which I should choose, and an installer program from AMI, one of the best-known BIOS vendors.

Next, it was time to hit Google. I searched on (with quotes): "810LR BIOS". I found a third-party user group called the PC Chips Lottery BBS. At that site and via links on it, I tracked down several FAQ pages, even a FAQ devoted specifically to the model of motherboard I use. I also found relevant user discussion forums. The M810LMR FAQ had several interesting items about the revision history of the motherboard, including which CPUs work (or don't) with which motherboard versions.

Next, I Googled my motherboard model number, CPU name/speed, and "BIOS" as keywords: M810LR "Duron 1800" BIOS. Based on the returned results, I went to Milt's PCChips M810L BIOS page, which had both vendor and custom BIOSes. The custom BIOSes include features such as custom memory timing and control of many other parameters that hardware tweakers can use. An image of a parameter setting screen from a customized BIOS is shown below. Note: The illustration shows what's available in a typical customized BIOS; this should help you to determine whether you want to try one.

Milt's page also linked an alternative installer program called Uniflash, which works on a wide range of BIOS and flash memory chips. It may work for you, too, if the vendor's BIOS flash program doesn't. But try the vendor's flash software first.

For those who don't have a PCChips M810 motherboard, the Rebel's Haven Computer Forum points to several custom BIOSes for various motherboards, though not for all.

If none of these help you, keep searching the Web. Many sites provide custom BIOS information for motherboards. You should eventually find one that covers your motherboard.