PIII-800 (133MHz FSB) w/ 100MHz FSB Mobo (Abit BE6-2)???

[Mortikhan]

I am currently running a PII-400 on an Abit BE6-II motherboard. I am looking to upgrade my CPU to a PIII-800 or 850MHz to get the benefit of the Coppermine core. I'm assuming that, with a mobo BIOS flash, I won't have a problem doing this. However, I would like to purchase the 133MHz FSB version of the processor to maximize my upgrade options. Can anyone tell me whether or not I can run a processor designed for the 133MHz FSB at 100MHz (maybe even 133MHz) on the Abit BE6-II without any problems?

 

[Tonec]

A 133fsb p3 can run at 800mhz 133fsb/100agp/33pci/133ram or at 600mhz 100fsb/66agp/33pci/100ram. If you thinking of running 800mhx 133fsb/66agp/33pci/100ram then you need a via chipset.

 

[NixPhoenix]

Yea, of course you can underclock it, just remember to disable that identify speed option(which should be off already). If you decide to test with 133MHz bus, remember this. The only things which have to run at 133MHz are: The CPU(no probs), the AGP card(not really,(133/3)*2=89) most will do it if you set AGP Transfer mode to Normal and the "in order queue depth" to 1.
And finally the memory so you should have good PC100(8ns will do) or PC133.
You can read about this in a little BX133 guide that came with your mb.

 

[Mortikhan]

Thanks guys.

I flashed my BIOS and I still only have the 1/1 or 2/3 AGP clock options. So, you're absolutely right, - I'd be overclocking the AGP bus if I ran at 133MHz. Kind of a bummer, since I've heard that it's not a very reliable thing to do. (The Voodoo 5 is supposed to run hot without overclocking anyway).

Nix, - you mentioned disabling "that identify speed option", but I didn't see anything like that in my BIOS settings. I'll look again, but is that something specific to certain motherboards?

Thanks again.

 

[Stallion]

Some Vid cards will run at 89mhz. My GTS 2 will. But like Tonec said, if you don't want to OC your AGP you need a VIA mobo.

What Nix might be talking about is the Speed hold error in the Bios.

You need to disable it to turn up the FSB.

 

[Dexion]

He's talking about "Speed Error" located in the CPU speed adjustment screen, should be right below the L2 Cache latency.

As for the BE6-2, I've previously owned a P3-650 that was overclocked to 950 at 143mhz FSB. I had a TNT2 Ultra that did fine even under that OC'd AGP bus. If you want to play it safe, pick up a 750E/100mhz CPU instead. If overclocking isn't problem for you and you feel you need the speed, simply up the FSB a tad higher to reach 850mhz, its nothing a coppermine core won't do with a little voltage.

 

[Stallion]

I was just going to suggest that also Dexion. Get a 700/750 and turn up the FSB to 110-115 or so and then some day if you get a vid card that will do 89mhz crank it on up to 133.

My Diamond viper 770 ultra did would take a FSB of 124mhz (82mhz)then when I got my GTS I upped it to 133. At 124 the PCI is running a little fast to so 115 might be a better choice.