GFD Overclocking Basics
One of the most common
questions I'm asked is "How fast do you think my Athlon will
go?" Excellent question.
AMD's production
yields are so good with this chip they rate the processor lower
than it can actually perform, and use cores from higher rated
processors to meet market demand for lower ranges of speed. Let's
take a look at how it works.
By the way, GFD
(Golden Finger Device) refers to all Athlon overclocking cards.
The 'golden fingers' is a term used to describe the internal debug
connector (highlighted below) on the Athlon's circuit board that
the card attaches to.
What's under the
hood?
You can make a fair
assumption as to how well your K7 will overclock by finding the
production week of the CPU.
To give you a general idea of the core and cache speeds without
opening up the Athlon, you need to find the production week in the
serial number printed in the spine of the case. It will be the
bottom row of numbers, under the AMD-K7850xxxxxx. The week will be
the fifth and sixth numbers in the string. (xxxx02xxxxxx).
Once you have that
info, compare it to what others have posted about their results in
this database: http://www.ninjamicros.com/leaderboard.html
But, you can only be
100% sure of your core and cache speed if you open it up, take off
the heat plate (careful!) and look at them. Removing the heatplate
is not necessary to use a GFD. The Tech Zone offers more direction
on removing the heatplate in this article, and deciphering the
numbers printed on the core and cache chips here.
How fast you can
overclock your chip is a factor of:
1.) The core
speed. Many Athlons have a higher core speed than their case
indicates (production week 42 on) due to AMD's excellent yields.
For example, my ("old") week 47 500MHz has an actual
processor core of 650MHz.
2.) The speed of
the cache memory. Athlons produced in week 42 on vary on cache
speed from 3ns to 4ns. The faster the cache speed the more stable
it will be at higher speeds. With my Athlon's 650MHz core and 3ns
cache, it's comfortable running at 824MHz.
3.) The clock
multiplier. Athlons' clock multiplier is locked, meaning its
resistors are soldered to it's specified speed, and can't be
changed via motherboard jumper or BIOS setting. Hence the need for
an overclocking card.
4.) The
motherboard's Font Side Bus (FSB) setting. The speed of a cpu,
generally, is determined by taking the FSB and multiplying it by
the multiplier. (i.e. 100MHz fsb x a multiplier of 5 = 500MHz cpu)
Overclocking the cpu via increasing the FSB leads to an UNSTABLE
system.
5.)The cache
divider. By default the K7's cache divider is 1/2, meaning the
cache memory operates at 1/2 the speed of the cpu. Over 750MHz the
cache divider switches to 1/3, resulting in slightly slower
performance.
6.) Core
voltage. The default voltage for the K7 is 1.6v As you increase
speed the cpu needs more power (which translates into more heat),
so the core voltage needs increased. Another need for a GFD. (over
1.9v can be very dangerous without excellent cooling).
___________________________________________
Opening
the Athlon
(up)
Pictures
and technique provided by TheTechZone.com
(From
the top) Plastic Case, Heat plate, Naked Athlon
If you
want to overclock the AMD chip you will need to open up the Athlon
to change it's speed settings. Another reason for ripping out the
case is because the Athlon will run cooler once it's stripped down
to bare PCB. The casing that house the CPU traps heat, not good if
you plan to overclock.
One
word of caution. This operation is not for the weak at heart.
Removing the Athlon casing could kill the CPU if you make a slip.
I, of course, will not be held responsible.
You
only require one tool to remove an Athlon casing, a big flat head
screwdriver.
The
Athlon is held in its casing by 8 pins. You can see them in the
above photo. The 4 outer pins hold the heat transfer plate to the
plastic casing and the 4 inside pins hold the CPU to the heat
transfer Plate.
Removing
the CPU out of the casing is pretty easy compared to removing the
Athlon off the heat transfer plate. Begin by taking your
screwdriver and jamming it between the plastic casing and the heat
transfer plate near the first pin. Be very careful.
Now
push the screwdriver down like the above photo. The screwdriver
will separate the heat transfer plate from the casing but it's not
enough to pop the pin out of the casing. To do that give the
screwdriver a 45 degree turn.
Congrats!
You have just broken the first pin! Repeat the same procedure for
the other 3 outside pins and you can remove the AMD case.
Pin #4 (lower left) is notoriously difficult to release. A lot of
force and/or finesse may be needed to free it. This may result in
a broken plastic case. Airflow around the CPU is better with it
off anyway.
Your
heatsink will attach to the heat plate on the other side of the
Athlon's circuit board in the picture above.
___________________________________________
Installing
and Testing Your GFD (up)
The
GFD card now simply slots onto the internal connector on top of
your Athlon. Just make sure that the switches face the
heatsink/fan side of the Athlon.
Athlon with FreeSpeed Pro and Alpha P7125 heatsink
Testing For the Highest Overclocked Speed
So,
the GFD adjusts the clock multiplier and the core voltage. This is
done by changing the dipswitches on the card. It's simple, just
follow the chart that comes with it. Or, check out the online
charts.
The
TD2 settings are HERE
The FreeSpeed Pro settings (email
us)
Begin
by setting the dipswitches to your CPU's default speed and voltage
settings, this will make sure the card is functioning properly. If
you're using a card that requires external power, plug it in now.
Place the card on the debug connector, and power up you computer.
If it boots normally, shut it back down and continue.
Increasing
the speed slowly is important, like 50MHz at a time, to see where
your cpu will be stable. Run some apps, games, benchmark programs
and such at each level to test stability. When things start acting
goofy (won't boot into Windows, crashes, errors, etc.) up the
voltage 0.05v and test again. (I wouldn't go over 1.85v)
When
you finally get to the highest voltage your willing to run, up the
MHz till the first sign of instability, then back the speed down
50MHz to ensure a stable system.
Keep
in mind that excellent CPU cooling is needed. A good cooling
system may actually help you achieve higher speeds, not to mention
prolong the Athlon's lifespan.
If you
have any questions email us: Support@highspeedpc.com
(up)
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