P4PE Jumperfree mode?

Hi all,

I am thinking about playing around with overclocking my 2.4 P4 (533Mhz) on
my ASUS P4PE, but I cannot find how to put the motherboard in Jumperfree
mode. The manual refers to it, but there is no explanation. I know it is
usually a "JEN" jumper, but I can't find one on my motherboard.

I am running and old version 1002 BIOS, as I have had no issues with this
motherboard, so I am thinking maybe it was added later in the BIOS, and
maybe there is no jumper. The multiplier is grayed out in the BIOS, even
when I set to manual mode.

Any ideas?

 

I have that motherboard. There are no jumpers. It's all adjusted in the
BIOS.

 

Thanks Dave.

OK. When I set it to manual, the BIOS then allows me to adjust the CPU
external frequency. The CPU multiplier is still grayed out. I presume then I
have a "locked" processor, and that is why I cannot change the multiplier?

--
Dan Braasch

 

Unless the processor is an Intel ES (Engineering Sample), it will be
locked. To overclock, you raise the FSB, and the core rises in proportion,
as well as the memory. To prevent the memory from going over spec, you
turn down the memory, to the next lowest setting.

Say you have FSB533, and some PC2700 memory. The memory is rated at
DDR333. Say the memory is already set at DDR333. So, you set the memory
to the DDR266 setting. (FSB533 is 133MHz CPU clock times four, to get
the FSB transfer rate.)

If you now raise the clock from 133MHz to 166MHz, the core frequency
will increase by Fcore*166/133. But the memory will also be increased
in the same way. So it would go up by DDR266 * 166/133 or DDR332. So
now the memory is still just within spec. If we hadn't turned down the
memory, and left it at DDR333, the memory would be DDR333 * 166/133 = DDR416.

The Asus provided overclocking information for the board, says it would
do up to FSB800, but by doing so, you are limited to one stick of
memory at DDR400. So if you plan on cranking the memory bus very
high, you have to think a bit about how many sticks you can manage
to run at high speed. Turning down the memory clock setting a bit,
while you establish how high the CPU will overclock, will allow you
to determine the CPU limit, and then you can do some separate
experiments with the memory subsystem.

Also of note, it looks like your motherboard has an AGP/PCI lock
function. Notice that you can set it to "Manual" and select 66.66/33.33
for the AGP and PCI clocks. By doing that, that will prevent hard drive
corruption caused by overclocking the IDE interface. You
should do a bit of Googling, to find out more about whether the
AGP/PCI lock really works on your motherboard or not. You have to
be careful with that function, because sometimes it doesn't work as
expected, and you really need to find confirmation that it works
correctly, somewhere.

In terms of overclocks, you work in tiny increments, to make it
easier to detect the limits. For example, it may sound strange,
but if you are at 133MHz now, you could go up in steps of 5MHz at
a time, and see how it goes. My guess is you'll get to FSB640 or
so, so it should take you about 5 or 6 tests to get there. In the
case of my own machine (not a P4PE), increasing Vcore didn't really
help me a lot, and it appears my motherboard is letting me down. My
machine "hits a wall", once I get to a certain level of overclock.

In terms of test procedures, I recommend disconnecting your
regular disk drive, and cook up another kind of test. I have
a Knoppix and a Ubuntu CD, and those are "read-only" and bootable
disk images. I apply an overclock in the BIOS, and set the
CD as the boot device. If icons start to disappear from the Linux
desktop, that tells you the machine is overclocked too high
You can also see a variety of error messages, as the machine is
booting. Using a Linux boot CD, is a lot safer than messing up
your Windows boot disk, while in some unstable overclock
situation. If you don't have high speed Internet, to download
a Linux distro, you can also do a clean install of Windows on
a spare disk, and use that as your sacrificial boot disk.

Paul

 

Thanks for the detailed post, Paul. Very helpful.

 

Paul,

I successfully overclocked my P4PE with 2.4G P4 to 167 (668) FSB, 334 PCI.
Anything above that I started seeing noticeable temperature increases in the
CPU. The AGP/PCI locking worked fine. So I now have a 3.0G P4! Been running
like this for 6 days now, just as stable as before overclock.

So I decided to tackle my daughter's ASUS TUSL2-C with P-III Tualatin 1.2G.
I brought both the FSB and memory bus up to 150, and the PCI is at 37.
Everything is running stable there, too. If I tried to lower the memory
clock to get more out of the CPU, it didn't like it much. So I experimented
a bit, and it has been running stable at this setup for 5 days.

Thanks for your input. I feel like I have 2 new PCs.

Dan