Archived from groups: alt.comp.periphs.mainboard.epox (
More info?)
> Don't recall having applied any new BIOS at the time I noticed it - however
> had recently installed the new GFX card - could it be anything to do with
> AGP settings etc?????
No AGP settings should not affect your ability to change FSB speeds.
>
> PHSSTPOK - Not sure what is meant by the 1/3 & 1/4 divider business - can
> you please clarify?
>
Sure, I'll try.
PCI and AGP buses run at speeds based on a base clock, the host clock
used for FSB, Front Side Bus. A divider is used. If your FSB speed
is 100 Mhz then a 1/3 divider is used for the PCI clock and 2/3 for
the AGP clock. This means PCI would normally be 100/3 or 33 Mhz and
AGP would be at 66 Mhz which are the industry stand speeds for PCI and
AGP, respectively.
When you increase the FSB, the 1/3 and 2/3 dividers remain in effect
up to a certain point. If you increase to 123 Mhz, as you have done,
you overclock both buses, the PCI bus to 41 Mhz (123 divided by 3) and
AGP to 82 Mhz.
At or around 128 Mhz the EP-8KTA3PRO (don't recall the exact
frequency) switches to 1/4 and 1/2 (two forths) dividers. So at 128
Mhz, instead of having PCI overclocked to 42.666 Mhz (128 divided by
3), it is now using the 1/4 divider and running at 32 Mhz (128 divided
by 4). A slightly low but certainly safe speed for all PCI devices.
The 1/3 PCI divider is the most likely reason you can't push your FSB
to 124 Mhz.
Not being able to run your Athlon at 1333 Mhz (its intended speed)
with a 133 Mhz FSB is different problem (IMO). Obviously now with 1/4
and 1/2 dividers, PCI and AGP would be at the correct speeds. An
overclocked PCI device would not be the cause of your problem in this
case. This is why I thought you had the BIOS version that introduced
a similar symptom, which is not being able to run FSB at 133 Mhz.
I think we need more information to solve your problem.
What graphics card, make/model/type were you using previously? and now
(guess you said GF3)?
What are your system and CPU temps at the highest speed that you can
obtain?
What brand/type/speed ratings is your memory?
What brand/model/wattage rating is your power supply?
In the meantime you could try rolling back to an earlier BIOS just in
case you do have the BIOS issue I mentioned earlier.
I find the October 19, 2001 BIOS, 8K201A19, to be the most stable BIOS
of them all but I use the May 28, 2003 beta BIOS, 8K203528 (because it
correctly identifies my Tbred). It also supports enabling/disabling
SSE with Tbreds/Bartons and presumably with Applebred/Thorton (not
important to me). Though, none of these processors are officially
supported on the Epox 8KTA3PRO.
PM me if you need help.
Steve Sheppard
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