Okay, for those ultimate crack rackers on a *budget* and
who want to squeeze just a few more Mhz out of their
Celeron II Socket 370 chips in a Socket 370 motherboard
which does not support voltage adjustment in BIOS or via
jumpers on board, listen up....
For starters, I claim no responsibility, whatsoever, to
any thing you mess up. This is information is meant for
*real* overclockers who remember the days of changing out
the crystals on your motherboards...Gee, Gunny, remember back
to 1986 when I worked on your Zenith 386-20 that ran twice as
fast after I got done? That is how I did it. Proceeding beyond
this point and/or by altering your motherboard, you take 100%
responsibility for *any* and *all* gains, losses, smoke, fire,
and even acts of "God" (including Bill Gates, Microsoft, and
all things Intel, to include tickets received from the Intel
Overclock Police...)
Now to
VOID-VOID-VOID-VOID-VOID-VOID-VOID-VOID
*any* possible warranty you may have on any and
all parts of your computer, please proceed:
Download the datasheet from Intel on the Celeron,
(Intel Celeron Processor up to 800 Mhz) see page 18 Table 2
for voltage chart and page 87 for pinout.
See here:
http://developer.intel.com/design/celeron/datashts/
Once you have downloaded and reviewed the datasheet, especially
pages 18 and 87, along with the rest of the datasheet, you are
nearly ready to force your core voltage.
For our example, note Pins AL35 (VID0), AM36 (VID1), AL37 (VID2).
On a FC-PGA 533A and other Celeron II chips, the
default core voltage is 1.5 volts.
A high (1) on one of these pins means that there is no connection
in the CPU (no, it is not actively pulled up). A low (ground)
means it is 0, and is connected internally within the chip to
ground.
Since changing the core voltage from 1.5 volts to 1.65 volts is
the easiest, I will explain it.
Find someone who can solder well, and I *don't* mean your buddy
who just got his B.S.E.E. Assure the iron is ESD safe and
you follow ESD precautions.
Simply connect pins AL35 (VID0), AM36 (VID1), and
AL37 (VID2) together. The ground supplied from
AL37 (VID2) will supply a ground to AL35 (VID0) and
AM36 (VID1), which will make to core voltage go to 1.65 volts.
Thats it you are done.
For those more technically proficient, other voltages can easily
be achieved.
I have personally performed this modification and verified the
change in core voltage with an actual measurement.
Also, for those wanting to force a 100Mhz bus speed, see the BSEL
pins, and assure you read the app. note. To force a 133 fsb speed
on a chipset/clock generator/CPU that supports 133 but where it is
not a selection in BIOS/jumper see the PIII datasheet. Please note
that not all motherboards are created equal, and even though the
hardware on the printed circuit board supports 133 fsb, the board
may not function at this speed. When doing the 133 fsb, it is also
helpful to review the datasheets for your particular chipset/clock
generator. There are some really slick things you can accomplish
with a cheap motherboard with the right clock generator chip!
Please give credit where it is due, so if you pass this
along, please copy it, with this line and credit the modification
to Doug Leeper-a.k.a. Jarhead,TeamAnandTech RC-5
