asynchonous memory/FSB

[Bateluer]

Which mobos support this feature? I have an Asus CUV4x based on the Via Apollo Pro 133z, which is basicly the 133a with a few tweaks and AGP Pro. I ask because I want to oc my Cu500 cpu to 667 at least. I know the chip can handle it, but my memory is pc-100. Can my mobo clock the FSB speed independently of the memory bus? If so, how?

------------------
When Can I overclock a terahertz cpu?

[Arcadian]

Are you trying to ask if there are motherboards that allow you to clock the memory differently than the front side bus?

If so, I don't believe there are. I believe that the same clock is tied to both the front side bus and the memory speed (and other components of the motherboard as well). In the case of the i815, I think they have a divider so that you can use a CPU with 133MHz front side bus with PC100 memory, but I'm not sure of overclocking motherboards take advantage of this divider. Correct me if I'm wrong....

[sww]

Yes there are. Many in fact. e.g. all KT133 boards run memory at 133MHz and the FS bus at 100MHz x 2. Every motherboard I've had the last three years or so could also do this. Many older boards that supported 100MHz processors would let you clock your RAM at either 100MHz or at 66MHz.

[Arcadian]

Originally posted by sww:
Yes there are. Many in fact. e.g. all KT133 boards run memory at 133MHz and the FS bus at 100MHz x 2. Every motherboard I've had the last three years or so could also do this. Many older boards that supported 100MHz processors would let you clock your RAM at either 100MHz or at 66MHz.


For one thing, Bateluer said he had a Pentium III, so I didn't bother to go into KT133 based motherboards. In terms of motherboards for the Pentium III, I don't think there are any that support clocking the front side bus independantly of the memory speed with the exception of those that offer fixed dividers like the i815.

[BadSeed]

The ASUS CUCL2 (or is it CUSL2) can run the fsb and ram independantly. It's based on the Intel 815e chipset too, so you can run your P3 on this. I've read many good reviews on this board, and if I could afford one, I'd probably get one.

[LiquidGoop]

You CAN run them asynchonously, basically it's FSB+PCI clock, by default 100+33=133. However if you overclock the FSB on the p3, the FSB then PCI bus will also be higher, resulting in memory running much higher. eg, 150Mhz

[jtshaw]

Be very careful increasing anything that screws with the PCI bus speed too. Many PCI cards, especially hard drive controllers, will really get pissed off if you throw off there timing by increasing the PCI bus speed. Lots of PCI cards are made specifically for the standard PCI bus..keep that in mind.

Originally posted by LiquidGoop:
You CAN run them asynchonously, basically it's FSB+PCI clock, by default 100+33=133. However if you overclock the FSB on the p3, the FSB then PCI bus will also be higher, resulting in memory running much higher. eg, 150Mhz

[Sketch]

I have an Asus CUSL2 and am running a 133MHz FSB and PC100 memory at 100MHz. The bios auto-detects and sets it up right to start with, and you can also change it manually by changing the MEM:FSB:AGP ratio in the bios.