Overclocking my EPoX 8RDA3+ and Athlon XP 2100+

Where can I find some *good* information on how I
could overclock my system? Default it's 1.7GHz and
I only really want to overclock to about 2.1GHz or so.

MoBo: EPoX 8RDA+
CPU: Athlon 2100+ Thoroughbred revision B
Memory: Kingston 256MB DDR PC2700 333mhz

I've read some of the beginners guides out there but
none seemed very good. Most assumed you had info
that you probably didn't (eg, "Disable all the uselss BIOS
settings". Ok, which are useless?) If someone can point
me in the right direction, that'd be great!

 

Your particular situation just happens to be about as easy as it gets...

The XP2100 has 133MHz FSB, and 12.5X multiplier.

Your motherboard and memory are both good up to at least 166MHz FSB
(DDR333) and memory.

Leaving multiplier alone, raise FSB speed to 166MHz... Result is 2.08GHz,
close enough to your target speed. Default CPU voltage might be 1.65V?
Raise that BEFORE changing FSB rate, around 1.7V might be about right for
what you're wanting to do but can vary per each unique specimen of CPU
even when same "XP" rating, but 1.7V should be in the ballpark.

If you've changed any other bios settings you should write down and
changes made, as there's a fair chance you may need to use the clear CMOS
jumper if the board doesn't gracefully recover with a "watchdog timer",
which essentially reverts FSB speed back to default setting if system
doesn't POST. Familiarize yourself with location of the clear CMOS
jumper.

If system won't POST at all, you have two alternatives, lower the bus
speed to result in lower CPU speed, or raise voltage. Keep in mind that
temp WILL rise and if you're using a mediocre heatsink you may have temp
issues above 1.65-1.75V, also depending on fan, case cooling, ambient
temps, etc.

After changing FSB speed, verifying that memory bus is set synchrous to
(same speed as) memory bus, somtimes labeled as "100%" in nForce2 bios
(dont' know for sure about that board), DO NOT BOOT TO THE OPERATING
SYSTEM. Have a memtest86 floppy ready (http://www.memtest86.com) and
test the system for several hours... It must pass this test without any
errors before running the OS to avoid (or at least minimize) potential for
errors. If errors occur you can do one or more of the following:

1) Use different memory
2) Lower memory bus rate percentage or keep it synchronous and lower FSB
rate
3) Change memory timings to slower values (higher numbers).
4) Raise memory voltage (generally for advanced users only).

You are taking the system's stability into your own hands, it's up to you
to asses the importance of stability and how much you're willing to test
the system to confirm this. One popular way to test CPU is with Prime95's
Torture Test (particularly the "In Place Large FFTs" setting). Run that
test and the full/default torture test for several hours. Another good
test might be continual loops of 3DMark (whichever version is appropriate
for your video card... if your video card isn't able to run 3DMark 2003
very fast it's not much of a test, the rest of the system is mostly
waiting on the video card which wouldn't be overclocked at all given the
aforementioned FSB rate change, unless you'd ALSO changed AGP-related
settings in the BIOS.

Certainly this was not a comprehensive post, but it's enought to get you
started. Watch the CPU temps and backup your data before booting to the
operating system. Overclocking can also reveal flaws in other margin
components like a barely-adequate power supply or low-end motherboard....
do so at your own risk, plenty of people have good results but KNOW what
you're doing and why, particularly if this is your only or primary-use
system and you can't afford any significant system downtime.

You might also find overclocking and mod guides specific to your
motherboard with a Google search, or try here:
http://forums.pcper.com/forumdisplay.php?f=9

 

http://www.overclock.net/

 

http://www.overclockers.com/

 

Set FSB to 161 (13x161=about 2100MHz.). Run ram in sync. Set vcore to
1.65v or higher if needed for stabilty. Multplier x FSB clock = cpu speed.
The default multiplier for the 2100+ is 13. Shouldn't have a problem at
13x166 (2166MHz) either. That's where I usually run mine.

 

OOPS!

As Wes pointed out, the default multiplier on those is 13X, not 12.5X.
Adjust rest of what I posted accordingly, you may still be able to run 13
X 166MHz FSB though you may be at the point where average CPU vCore
voltage needs 1.725, give or take +-.05V

 

Do you set the new vcore value in the "Power BIOS Features" section under
CPU Voltage Regulator?

thnx,
Sorrow

 

It should be in the bios somewhere or mybe via jumpers on the board. I
don't know, I don't have an epox board.

 

As Wes pointed out, the default multiplier on those is 13X, not 12.5X.

The only things that I changed in the BIOS was the FSB (to 166MHz) and
the value for "CPU Voltage Regulator" in the "Power BIOS Features" area.
That last I changed to 1.7. Prime95 ran fine for about 6+ hours and then it
locked up. I was running MBM5 at the time and having it log. Below is the
first and last readout in that log. Do these numbers seem right? Are any
too low/high?

+-------------------------------------------------------------------------+
|Total number of readouts: 533 CPU Speed: 2176 MHz |
|Running from: 6/6/2004 7:16:29 PM until: 6/6/2004 8:45:34 PM |
+-----------------------------+----------+----------+----------+----------+
|Sensor | Current | Low | High | Average |
+-----------------------------+----------+----------+----------+----------+
|Case | 32° C | 31° C | 32° C | 31° C |
|CPU | 64° C | 52° C | 66° C | 63° C |
|Sensor 3 | 0° C | 0° C | 0° C | 0° C |
|Core 0 | 1.60 V | 1.58 V | 1.60 V | 1.60 V |
|Core 1 | 1.66 V | 1.65 V | 1.71 V | 1.67 V |
|+3.3 | 2.59 V | 2.56 V | 2.66 V | 2.60 V |
|+5.00 | 5.00 V | 4.97 V | 5.00 V | 4.98 V |
|+12.00 | 11.86 V | 11.80 V | 11.92 V | 11.85 V |
|-12.00 | -7.09 V | -7.17 V | -7.09 V | -7.10 V |
|-5.00 | -1.27 V | -1.27 V | -1.25 V | -1.27 V |
|Fan 1 | 1513 RPM | 1328 RPM | 1534 RPM | 1339 RPM |
|Fan 2 | 0 RPM | 0 RPM | 0 RPM | 0 RPM |

|Fan 3 | 4891 RPM | 4687 RPM | 4891 RPM | 4807 RPM |
+-----------------------------+----------+----------+----------+----------+


+-------------------------------------------------------------------------+
|Total number of readouts: 1432 CPU Speed: 2176 MHz |
|Running from: 6/6/2004 7:16:29 PM until: 6/6/2004 11:14:57 PM |
+-----------------------------+----------+----------+----------+----------+
|Sensor | Current | Low | High | Average |
+-----------------------------+----------+----------+----------+----------+
|Case | 33° C | 31° C | 33° C | 32° C |
|CPU | 64° C | 52° C | 66° C | 64° C |
|Sensor 3 | 0° C | 0° C | 0° C | 0° C |
|Core 0 | 1.60 V | 1.58 V | 1.60 V | 1.60 V |
|Core 1 | 1.66 V | 1.63 V | 1.71 V | 1.67 V |
|+3.3 | 2.61 V | 2.54 V | 2.66 V | 2.60 V |
|+5.00 | 4.97 V | 4.97 V | 5.00 V | 4.98 V |
|+12.00 | 11.86 V | 11.73 V | 11.92 V | 11.85 V |
|-12.00 | -7.09 V | -7.17 V | -7.09 V | -7.10 V |
|-5.00 | -1.27 V | -1.27 V | -1.25 V | -1.27 V |
|Fan 1 | 1520 RPM | 1328 RPM | 1555 RPM | 1451 RPM |
|Fan 2 | 0 RPM | 0 RPM | 0 RPM | 0 RPM |
|Fan 3 | 4891 RPM | 4687 RPM | 4891 RPM | 4808 RPM |
+-----------------------------+----------+----------+----------+----------+

 

One thing important to mention, is that some systems can't even run
Prime95 all day when they're NOT overclocked! A baseline is important.
In other words, before any test you should've already used same test with
system at stock speed, or at least rerun test that fails, at stock speed.

In first readings the core voltage was dropped down to 1.65... your
motherboard may be somewhat limiting your overclock. You might try
running at lower voltage, it seems your temp, at 66C, was too high for
comfort when overclocking.

The 12V reading, @ 11.73, is within acceptable limits yet also looks to be
dipping a bit, but could also be the motherboard's fault. You could take
a 12V reading at a power supply plug with a multimeter and compare to the
motherboard monitor reading, and further compare what MBM shows with
system not overclocked. It's not really important to do that though, but
you ought to check the 12V reading at hard drive to confirm that only the
motherboard is seeing these dips.

Basically I suspect the CPU is getting too hot, so your options are a
better heatsink, trying a lower voltage, and/or reducing clock speed some.

An alternate way of doing it might be to lower the voltage to 1.65V, then
adjust FSB as high as it'll go while staying stable @ 1.65V... just
depends on how much work you want to put into that last couple hundred
MHz.

 

That +3.3v is very low. Not that it will necessarily be a problem. Mine was
running similar levels but stable ([email protected]), however, I elected to
replace the PSU anyway. The graphics card runs off the 3.3v and, in a lot of
cases, the graphics card is the most expensive component in a PC, not worth
risking it.

Luck,

 

But the 3.3V is SO low that I don't even think it is the 3.3V reading, it
looks more like the memory voltage and that's just a bios bug that it
reports wrong sensor.

 

Could be. My 3.3v rail was nearly that low and the machine was functioning
Ok before I bought a new PSU.