Dividers 1/5 and 1/6 on 8KHA+ DO exist!

[patto]

Dividers 1/5 and 1/6 on 8KHA+ exist and Epox Tech knows it.

If you read the various posts that Epox Tech has made over the past month you can easily "read between the lines" and realise that he has been hinting that the 1/5 and 1/6 dividers exist.

However as Daniel ~ pointed out in the sticky thread, Epox Tech
"must uphold EPoX policy, which in turn must take a great many things into consideration. These are practical, business and legal considerations"

The fact is im running at 200fsb and so is Omrons. This has been done by enabling the 3/4 memory divider. My system is rock solid. Yet i know it is impossible for my Netgear NIC and my SBLive to be running fine at 50mhz.

My only conclusion is that the 1/6 divider has kicked in. (if you go back and read EPOX tech's posts he says:

"(8KHA's dividers mean it does not ever go above 39Mhz PCI, so BIOS alteration alone is safe upto 200Mhz). "
BIOS isnt seeing the clockspeed, AGP mulitplier, or the bus speeds

Based on the above comment you can work out this:

100-117FSB ---- 1/3
118-156FSB ---- 1/4
157-195FSB ---- 1/5
196-234FSB ---- 1/6
235-273FSB ---- 1/7?? (probably too high for the KT266A)


BTW thanks for all your hard work and advice Epox Tech

[patto]

Oh and BTW im running

Epox 8KHA+
AMD 1.2Ghz
256 PC2400 Kinston
64mb Leadtek GF2 TH (Titanium)
SB Live
Netgear FA310TX

@

200mhz FSB
150mhz memory
66mhz AGP
33mhz PCI

with TBird @ 6 x 200 = 1200mhz

(ill overclock the TBird once i settle on a Epox config. ill prolly go back to 166FSB and 166memory because of the faster memory performance)

[Paul.K]

The Epox Tech guy around here has said that the PCI divider 1/5 is not supported by the Via KT266 chipset. With there bios update they must of tinkered with PCI latency.....


Paul.K

[Aedan]

Originally posted by patto
Dividers 1/5 and 1/6 on 8KHA+ exist and Epox Tech knows it.

The easiest way to work out if a motherboard supports a specific divider ratio is to look up the datasheet on the clock generator.

The clock generator's job is to produce the various frequencies required from a master signal. If the clock generator supports a particular divider, then you're set. If the clock generator does not support the divider you're after, then no amount of tinkering will help.

The Chipset does not generate the clocks, nor does it provide the divided clock signals. Technically, this is because things like clock skew tend to make boards less stable. Having the clock generator generate all frequencies from a master signal means there is little clock skew between the various clock signals.

AidanII

[rocky500]

Taken into account from what "patto" says the Epox 8kha+ can run Dividers 1/5 and 1/6 & also what "AidanII" says about the clock generator doing the work then all the following boards should be able to do the same:

Soltek SL-75DRV2

Gigabyte GA-7VTXH

Reading Tom's Hardware review on the m/b's shows these 2 boards have the same clock generator chip.

[spirits247]

Don't trust everything Epox/Abit etc. and Via tell you - their official stance would be the chipset doesn't support it.

The next chipset from Via is set to officially support 166FSB (KT333 and KT333A?), so why would they kill their next round of sales by officially saying the KT266A supports this standard?

That's right, they won't. The board may still use these 1/5 and 2/5 dividers but they will not officially give it 333 support, only 266. At the same time however, they are happy to see the reviews giving it good marks for overclocking so work out how they get the best of both worlds

Below is a thread I wrote summerising how I understand the info spread out across this forum from guys such as dimmreaper, aidanII and others.

Read here for a summary of how motherboards select dividers

[rocky500]

I did a search on the clock gen chip & found a PDF file that has on page 6 some dividers.
http://www.icst.com/pdf/94228.pdf

I'm not so technical on this but it looks something like this:

CPUCLK AGPCLK PCICLK
233.33 77.78 38.88

200 66.67 33.33


Does this mean something?

[EPoX Tech]

Paul K is quite right in pointing out what I stated about KT266 and 8KHA+ in varying replies.

[EPoX Tech]

Originally posted by rocky500
I did a search on the clock gen chip & found a PDF file that has on page 6 some dividers.
http://www.icst.com/pdf/94228.pdf

I'm not so technical on this but it looks something like this:

CPUCLK AGPCLK PCICLK
233.33 77.78 38.88

200 66.67 33.33


Does this mean something?

That is information about the clock generator which generates the FSB frequency, not the chipset.

[rocky500]

I posted before I saw your post "spirits247" it has the same thing with the clock gen.

Does that mean the most dangerous settings & fastest where you can damage Video Cards, memory etc is at the highest ones.
say 150MHz, 190MHz & 233MHz(I wish) were cards etc are out of spec the most?

[spirits247]

*IF* that theory is correct then yes at 159 FSB your PCI/AGP will be 39.75/79.5, while at 160 it will be 32/64.

But remember that there is no guarantee that the KT266A chipset is performing correctly with the cards/HD's at these higher FSB, as it's still running out of spec regardless of the dividers.

[rocky500]

I was curious because I've just joined the L1 bridges on my XP 1600+ CPU & was about to try & overclock.

It might be nice to know were the danger points will be along the way with the MHz settings.

I might try & get mine as high as I can get while keeping my cards in a "safe zone" so to speak.

so for an eg. 166MHz might be safer than say 150MHz in the long run.

[dimmreaper]

All that matters is that this board is capable of some killer FSBs. "Why?" is an irrelivent question.

[dimmreaper]

Originally posted by rocky500
It might be nice to know were the danger points will be along the way with the MHz settings.

Clock frequency will not kill parts. Heat and Voltage will, but not frequency. The only thing you will ever have to worry about is data integrety, EPoX was nice enough to bundle Nortan Ghost with the retail packaged 8kha+ boards so that too is null.

[EPoX Tech]

Hi dimmreaper - nice to see you after my break.

Guys - do note what I said about the pll generating a FSB frequency for the chipset.

[patto]

Can't you guys see that EPoX Tech is always trying to tiptoe around the issue. (No offense to EPoX Tech)

The KT266, the KT266A and of course the 8KHA+ mboard ALL DONT SUPPORT the 1/5 & 1/6 dividers. These aren't supported because in order to need a 1/5 divider you need a FSB of 166mhz. This is out of official spec so of course it isn't supported.

There is a differerence between "supported" and capable.


Hey guys just look at this EPoX Tech said:
"People keep asking questions, but my system keeps performing admirably at 172MHz FSB."
What i believe is being hinted at is "look at my system would I be running it this high if the PCI was so far out of spec"

If the other dividers didn't exist then the PCI bus would be running at 43mhz which is way higher than:
"(8KHA's dividers mean it does not ever go above 39Mhz PCI, so BIOS alteration alone is safe upto 200Mhz). "

[patto]

As EPoX Tech has been consistantly pointing out. It is the PLL administering dividers not the actual KT266A chipset.

EPoX Tech
"Only on mainboards where the PLL is able to automatically set the PCI divider. "

"I would like to think that my response is helpful to those doubting the mainboards ability to administer dividers that could otherwise be considered unconventional. "

ie: The PLL in the 8KHA+ is capabable of administrating unconventional dividers.

unconventional dividers = 1/5, 1/6, 1/7, 1/8 etc

[patto]

Originally posted by Paul.K
The Epox Tech guy around here has said that the PCI divider 1/5 is not supported by the Via KT266 chipset. With there bios update they must of tinkered with PCI latency.....


Paul.K

That is because it is not the chipset that allows the dividers it is the PLL. The chipset doesn't support it because then it will run out of spec.



OK guys im going to bed i'll be back in 24hours. BTW i actually know hardly anything about what i've been talking about. I have just been "reading in between the lines" in what EPoX Tech has been saying.

I also know that im running 200FSB and im sure (i hope) that my cards aren't running at 50mhz.

[wild_andy_c]

Do you have a full and comprehensive list of graphics cards and hard drives that will run at 200MHz Host Clock (400MHz FSB) from each manufacturer ?

[patto]

Originally posted by wild_andy_c
Do you have a full and comprehensive list of graphics cards and hard drives that will run at 200MHz Host Clock (400MHz FSB) from each manufacturer ?

If these dividers are working, which im 99.9% sure they are then ALL graphics cards and hard drives will work at speeds of a FSB of 200MHz. Since 200/6=33MHz then if the 1/6 divider works then it should be fine.

However to run at a FSB of 200MHz you need a good PSU. Also your running the chipset out of spec, but in our experiences the KT266A can cope with 200MHz.