fixed 33mhz, by extra pll (sort of like turbo pll)

if we solder in a 16mhz crystal instead of a 14mhz, we get a faster fsb speed, but everything else gets a lot faster. Which is why we build a turbo pll, so the 14mhz, 24mhz, 48mhz can stay at those speeds.

now, why not build one so we can keep the pci at 33 and the agp at 66?

some 845 and 850 chipset boards have this already. But of course the P4 is a load of ****.

would it be possible to do this on a kt266a board for example? or some other board? Or would the chipset be incompatible with this 33mhz, would it want the usual 1/4 and just not boot at all.

does anyone have any input into this?

[Mushkin Rules]

Brad, it is not possible to do so. VIA KT266A does not support any PCI and AGP divider. On KT266A mobo, AGP is controlled by VT8366A Northbridge and PCI is controlled by VT8233 Southbridge. Both chips do not support any PCI and AGP divider, as this is their limitation.

[EPoX Tech]

Originally posted by Mushkin Rules
Brad, it is not possible to do so. VIA KT266A does not support any PCI and AGP divider. On KT266A mobo, AGP is controlled by VT8366A Northbridge and PCI is controlled by VT8233 Southbridge. Both chips do not support any PCI and AGP divider, as this is their limitation.

Isn't this a general hardware query anyhow ?

[Mushkin Rules]

Epox Tech,
I think it's not possible to do it on VIA KT266A due to the chipset limitation, but I do not know if this can be done on other mobo. What do you think ?

[EPoX Tech]

Originally posted by Mushkin Rules
Epox Tech,
I think it's not possible to do it on VIA KT266A due to the chipset limitation, but I do not know if this can be done on other mobo. What do you think ?

I can't say too much on the subject but will say :-

The KT266a chipset is responsible for PCI and AGP control in it's south and northbridges as you state.

The frequencies output by a clock generator aren't necessarily always the speeds that a chipset uses - A chipset only needs an host clock reference to do all of the work with.

I don't think it is possible to modify from a 14MHz gear crystal to greater without beginning to upset the whole of the board to the point of it burning out.

I will state again however, I'm not sure as to the suitability of this thread in this topic area.

[Mushkin Rules]

Thanks Epox Tech, you're the good one

people have done it with 440bx's.

use a 16 - 18mhz crystal instead of the 14mhz.
solder in a 14mhz, 24mhz, 48mhz on the output of the clock gen
solder in a 33mhz, 66mhz to the output of the pci/agp pins on the clock gen

why can it work on the 440bx, not the kt266a? would it 'unsync' itself or something, like the kt266a will only accept 66mhz pci speed at 100, 133, 166, 200, and the southbridge will only accept 33mhz pci at 100, 133, 166, 200.

so at 180fsb per say, if you sent the northbridge 66mhz agp speed, would it just not post, as the northbridge is expecting 2/5 x 180 = 72mhz

[EPoX Tech]

If it means that you can make the record become unstuck as it presently is, do the modification yourself and see if it works.

As the saying goes - action talks, something else walks.

yeah I know, some people at the [H] are really into it

[FireControl]

It has been done But you have to know What you're doing.What Thingies to change(you notice no parts list)I think it was Frankister (or something like that) aka turbo pll god.If you are good enough to know the mb down to component level you can Play and enjoy,if not you will cook and crisp.