Dear Listers I have a 486 motherboard as follows: OPTI-895GREEN 486WB. I have the manual. Currently I am running it with an Intel 486 DX4-100MZ CPU. I would like to replace the CPU with an AMD AM486 DX4-120 (but at 100MZ). Thew markings on the chip are - A80486DX4-120NV8T. The chip says 3 volts; does this mean 3.3 volts? >From what I can guess in the manual, all the jumper settings are the same for both CPUs. Am I correct in this assumption? Can I do any harm if I change some settings (according to guesses form the manual), as long as I don't change the voltage form 3.3 to 5? Joel Bluming [log in to unmask] I did a search once through yahoo for OPTi895 and it turned up several interesting bitmaps of the board and jumper locations for each cpu. I don't think the jumpers will be the same, although I can't promise because my bios are pretty old ( I have 4 OPTi895's) and they don't mention the AMD cpu's. I do know that the AMD cpu you have is a write-thru cache model ( NV8T ) as opposed to the faster write-back cache ( SV8B ) model. The voltage is 3.3 and your board may be 3.45 like mine, but the difference will not be a problem. If the existing Intel cpu is using write-back, and I will guess it does because of the WB on your board's part number, then you will see a decrease in performance when you install the AMD cpu. You will probably need to change a jumper to tell the board the AMD cpu does not support write-back caching. Some board manuals list the AMD write-back as an SL-DX4 in the tables of jumper settings to distinguish it from the write-thru model. Check your CMOS settings to see if there is a setting for cache and to verify if it is supporting write-back for the Intel DX4. You could try http://www.indi.nl/cgi.bin/getjumpers/cgi?14 or just www.indi.nl but the site is in Dutch since it is hosted in The Netherlands. I haven't tried it because it was an incredibly slow site, although it will be worth it if it answers your questions. tom turak