333FSB and KT333 - Tech Support Forums

squeech · September 27th, 2002, 01:20 AM

Hey all,

I'm on an info hunt now.

Does anybody have any information regarding the KT333's ability to run one of the new 333FSB Athlon chips coming out next month? I know I can just scale my FSB up to 166 in my BIOS, but I'm not yet sure if that's such a good idea.

Gimme all you've got! I need data!

**Martoch** · September 27th, 2002, 01:23 AM

If your board can support 333Mhz FSB, then sure it will work!

What motherboard are you talking about?

CERuppel · September 27th, 2002, 01:26 AM

Just remember that the Athlon chip has a 133 bus 'bottle neck'.

Your mobo can get cranked, but not the chip.

(Now I'm not so sure. "Hey Overclockers"!)

Atomic Rooster · September 27th, 2002, 01:37 AM

The KT333 chipset should be able to handle the new chips with no problem. If not, it's probably something an updated BIOS could handle.

CERuppel -
The Athlons can handle FSB speeds way above 133 MHz. I've had mine running just fine at 155 MHz FSB on my KT7A-RAID.

AuraEdge · September 27th, 2002, 01:47 AM

I've heard differently. The KT333 Cannot handle the new 333FSB Athlons at spec. The reason is that the chipset does not support the 1/5 PCI bus divider, which is essential for the board to run in spec at 333FSB. I also believe it is lacking the AGP divider necessary (which would be 2/5). Ive read about many of the KT400 boards supporting 1/5 PCI bus divider, as well at 1/6 PCI bus dividers (which would put the PCI bus in spec at even 400Mhz FSB).

Yes, the board may work at 333FSB regardless, but your PCI bus will be overclocked 25% (41Mhz instead of 33Mhz). This could make sensitive PCI cards not run.

Assuming theres no 2/5 AGP divider either, on which I've seen no news to suggest otherwise, the AGP bus would also be overclocked out of spec 25% (from 66Mhz to 83Mhz) Some well made AGP cards will have no problem with this, but others may not boot at this kind of AGP bus speed.

I'n order to support the 333FSB in spec, you would need three things

1) The correct AGP divider (2/5)
2) The correct PCI divider (1/5)
3) The ability for the actual chipset to run stable at 333FSB.

I think most KT333 boards have the third, but all of them lack the first two.

Or maybe I'm missing something since I see some confirmations in this thread.

EDIT - The 1/5 PCI divider seem to be present for the KT333 - Please read my 2nd post below this one.

bill1971 · September 27th, 2002, 02:04 AM

Aura:
Are the dividers sometimes called the "spread spectrum" in some
BIOSes? Or is that something else entirely? Just curious. . .
Thanks.

- Bill

squeech · September 27th, 2002, 02:24 AM

The board is a Gigabyte GA-7VRXP. I've heard that about the busses too. PCI is not matter because I have no PCI cards!!

However, I am a tad worried about AGP, and that was one of the things I wanted info on. I have a GeForce4 Ti4600, and it was sensitive enough in this board getting it to be stable.

Thanks so far! Keep it comin! I'm lovin it!

AuraEdge · September 27th, 2002, 02:38 AM

Entirely different. I've never actually figured out what spread spectrum really is.

Multipliers/Dividers are what a board uses to get speeds for other parts of the system based upon the FSB speed. Think of the FSB as the variable you can set, and everything else is derived from that.

Say you have a 2000+ CPU (running at 1.66Ghz) and some PC2700 on it (thats running at 333Mhz.

THe FSB is at 266Mhz DDR (133Mhz is the actual number, its just does two operations instead of one every time it does one so it is effectively doubled, so it is usually refered to as 266Mhz DDR)

Now based on this value of 133Mhz

CPU multiplier is at 12.5 (12.5x133Mhz = 1.66Ghz)
Memory bus multiplier is 4/5 (To run at 166Mhz Memory speed, which is 333Mhz DDR)
PCI Bus's (which is supposted to be at 33Mhz) runs on a 1/4 divider
AGP bus's (which is supposed to run at 66Mhz) runs on a 1/2
divider.

RamonGTP · September 27th, 2002, 03:53 AM

Many KT333 boards have the correct dividers to run the new athlon CPU's.... I know my EPoX 8K3A+ does... I can go into the bios and start increasing my FSB, once I hit 166mhz, the correct dividers automatically kick in and my AGP/PCI frequencies are back to normal, 66/33 respectively. And from what i've read else where, the whole divider thing could be as simple as a BIOS update.

-Ramon

thekemp · September 27th, 2002, 06:49 AM

i was thinking the same thing for my asus a7v333 its got an athlon xp 1800 in but when the new 333fsb cpus come to the uk i would like to upgrade to one of them.