1T not possible w/ 4x 256MB Corsair TWINX3200LLPT RAM?

[mpjesse]

Hola.

I've been doing some overclocking recently and decided to try and move from 2T to 1T. When I do this, the system will not POST. I have to clear the BIOS to get it up and running again. Anyone have a similar setup as mine and able to run 1T? If so, did you have to do anything to get it at 1T (like increase the voltage, lax timings, etc)? Note: I'm not overclocking anything when moving from 2T to 1T. Anyone have any suggestions?

System:
Asus A8N-SLI Premium
4x 256MB Corsair TWINX3200LLPT (2-3-2 timings)
Athlon x2 4200+ (manchester core)

Thanks homies.

-mpjesse

 

[RichPLS]

From what I have read, even on the ATI chipset, 4 chips lower require the lowering to 2T.

 

[Rugger]

You're using 256MB sticks...do you know if they have more than one bank/stick? If yes, then you more than likely will not be able to hit 2T with those four sticks. Unfortunately this is an issue with the A64 ODMC. With Winchester core CPUs, the FSB would be downclocked to 333 by default when there were more than 4 banks of memory. Venice fixed the downclock issue when running greater than 4 banks, but they have not resolved the 1T/2T Command Rate issues.

 

[Rugger]

It's actually more than 4 banks of memory. Furthermore, each stick can have more than one bank of memory. In almost all 512MB and larger memory sticks, there are two or more memory banks. Some of the 256MB sticks only have 1 bank perstick, but it sounds like his have more than one and that is causing the system to fail when trying to boot at 1T.

 

[RichPLS]

one bank = single sided, two banks = double sided

 

[Rugger]

Not necessarily...that is generally true, but you can have a single-sided module that has more than one bank. That's something that Brent schooled me on before he abandoned us for WoW.

 

[mpjesse]

Thanks guys. Yeah, whenever I clear the BIOS on this bitch it downclocks my memory to 333mhz. Thankfully I can override it and bring it back up to 400Mhz.

I guess I'm going to have to bite the bullet and buy 2x 1024MB DIMMs. (i told myself that if I upgrade my memory, I'm going to 2GB).



-mpjesse

 

[BaronMatrix]

From what I have heard around the Net, AMD doesn't officially support 1T for 4 DIMMS but the DFI boards will actually do it. I think Anand had an article about it a few months ago.

 

[Rugger]

The DFI RDX200 is the only board that has hit 1T with more than four banks. But they were only able to take it to 406Mhz before they had to scale back to 2T. What was interesting is this quote from the article:

However, what is truly unique is that the DFI LANParty UT RDX200 is the first board designed to run four double-sided 512MB or 1GB DIMMs at the fastest timings and a 1T Command Rate. In fact, AMD specifications tell us that this is impossible. To his credit, Oskar Wu and DFI found a way to accomplish the impossible.

AMD specs state that it is not possible.

Jesse: I've heard the Crucial Ballistix 1GB sticks are sweet and can take the OC with tighter timings and 1T.