Turbo PLL

[#13]

First off, make no mistake; I DO NOT belong here. I don't start this thread because I know anything about the subject, but because I think a discussion of the subject would be interesting and fruitful. (I hope I didn't make too many errors in this post; I'm not familiar w/ the terms and such. Thanks for your patience.)

I'm not so much interested in overclocking using higher frequency crystals; I just wondered if the "turbo pll" principle could be used on todays mainboards as a hardware clock lock. Or could it be used on a board such as the nForce2 to decrease the memory speed (assuming that option isn't available in bios), in combination w/ dual ddr to eliminate the fsb ceiling created by ddr speed limits w/out creating a memory bottlneck. Throw in a pci clock lock, and where is the limit for fsb? Who knows?

This of course makes assumptions that the above operations are available to be modified, and not burried in the core of the northbridge. I have no idea if that's the case, but it's worth discussing. That's why I made this thread. That's also why I'm officially bowing out of the discussion, because I'm sure I have nothing left to offer on the subject...

 

[XWRed1]

It sounds like you are thinking of changing the designed behavior of the chipset/motherboard, not just tweaking settings while running. Thats a non-trivial task, I think.

What do you mean using it as a hardware clock lock?

As far as I know, the turbo pll stuff used in stuff like SoftFSB was the twiddling of registers on some chip on the motherboard. A PLL chip I guess? I'm really vague about it, I read H-Oda's explanation a few years ago.

 

[#13]

Ooops, you're right. You can't lock the pci clock like that, but you can seperate it from the crystal change. I kinda got those two mixed up (like I said, I don't really belong here...). Maybe you could use a lower frequency crystal dedicated to pci to lower it's frequncy out of the gates. Maybe not. That's why I apologized in advance for any errors, I guess. I'll leave you all alone now...

 

[gone_fishin]

click here to turbo pll page in english

To give the thread a link to what is being discussed.

a discussion forum on the subject

 

[bigben2k]

Interesting.

I wonder if it would be possible to alter one, to re-create Intel's throttling on AMD...

 

[Gnufsh]

Right. It is possible to build a turbo-pll like device by cutting up an old mobo. You replace the 14.318 REF, 24, and 48 MHz signals of your motherboard with ones from the canaballized PLL-IC and crystal. Then replace the crystal on your mobo and volia! A few people have done it on the K7S5A to run at higher FSB's then te BIOS allows. As for replacing the PCI bus signals, I'm not sure. Since all the discussion about the dividers on the 8kha+, I think via's chipsets themselves need to support the divider (can you explain this? the NB isn't on the PCI bus, is it?). Arbitrarily changing the pci bus may then have strange consequences, I'm not sure.