The Asus K8S-MX mobo?http://www.asus.com/999/html/events/mb/socket754/k8s-mx/overview.htm
CPU (Processor) Support:http://www.cpu-upgrade.com/mb-ASUS/K8S-MX.html
IF, the mobo (MOtherBOard) is in a computer that is working, and internet capable, I suggest you use CPU-Z from CPUID.com
It's a free, tiny, tiny, program.
Information on CPU-Z on Wikipedia,http://en.wikipedia.org/wiki/CPU-Z
(Home page URL of CPU-Z is listed to the right)
Should you need help in downloading, installing, or using CPU-Z, simply state so in a Comment.
IF, the motherboard is Not in a working computer, then you need to Physically look at the top of the Processor's case.
You are looking for the Part Number.
Examples using the AMD Athlon 64 processors,http://en.wikipedia.org/wiki/List_of_amd_athlon_64_processors
(For the AMD Sempron processors, just type -
List of AMD Sempron processors, in the Wikipedia search box, and left-click on the magnifying glass icon.
Same thing with AMD Sempron 64)
Some basic photo examples of what the part number will look like, on the top of the Processor's case,
(Scroll the page down),http://www.cpu-world.com/CPUs/K8/TYPE-Athlon%2064.html
Your body carries Static electricity.
Static WILL fry out (Short Circuit) the hardware components inside a computer.
You probably won't see it, Or feel it.
The Processor is the MOST susceptible hardware component to static shock.
Handle it by the sides of the case, refrain from touching the pins on the bottom.
Work on a table. Computer unplugged from power, computer case open, TOUCH the metal frame of the computer case to relieve your body of Static.
If the motherboard is already out of the computer case, TOUCH the metal frame of an empty computer case, BEFORE you touch the motherboard.
On top of the Processor is a Heatsink.
This has to be removed.
There will then be Thermal Paste.
I use an old plastic credit card, (Non-static item) to scrape as much of the old thermal paste off, as I can.
Do Not bear down too hard, as you may make the Part Number unreadable.
I then follow with Q-tips dipped in Isopropyl Alcohol.
91 percent alcohol is best, but 70 percent will do in a pinch.
I would not recommend 50 percent.
(It's 50 percent Alcohol, and 50 percent Water. 91 percent Alcohol, and 9 percent Water is best)
It will take a lot of Q-tips dipped in alcohol, as old thermal paste is usually a gooey mess. (Unless it is dried up. Then it's worse)
Isopropyl Alcohol is EXTREMELY FLAMMABLE!!
Use in a WELL ventilated space with no flames, or sparks present.
Have any further questions simply state so in a Comment.
(Believe upper right of your page)