Motherboard Help Pages
3. I have just bought a new
processor to put in my system. how do I know what jumper settings
The first thing to set is the voltage.
This is listed on the processor itself (either as the only
voltage listed or as the core voltage.)
As a guide the settings are
normally (for socket 7 CPU)
Non MMX Processors - 3.54v
Intel MMX - 2.8v
Cyrix MII - 2.9v
AMD K6-2-3D - 2.2v (some at 2.4v)
(some motherboards do not support 2.4v but do have a 2.5v
setting which will work fine in general).
Motherboards for slot 1, slot
A,socket A and socket 370 processors are generally autosetting
Once the voltage is set then
the next thing to do is determine the bus speed and the multiplication
factor to use. Sometimes this is written on the chip (almost
all the Cyrix processors do this) and sometimes it is not.
As a general rule provided that the end figure is close to
the stated figure then the processor should run quite effectively.
For example an AMD K6-2-300 could run at 3x100 (100Mhz Bus
and multiplication factor of 3). But it would also run at
4x75 and at 4.5x66. So which is the best combination to use
if it is not stated on the chip? Well in theory the 3*100
should be slightly faster (but only by a few percent) than
the 4.5*66 because of the fact that the rest of the system
also uses the higher bus speed. However you may find that
some of the other components will not run reliably at the
higher bus speed so the lower bus speed may give less problems.
As a rule use the highest speed that the system runs reliably
at, and if you get problems try the lower speed to see if
the problems go away.
Some notable Processors settings
are: AMD K6-2-300 AFR66 - A 66MHz bus only processor AMD k6-2-333
- A 95MHz processor (but will of course run at 66MHz)
Cyrix settings see this page.