Clarify DDR Memory Question

[neonsurfer]

I'm going to be building my first AMD system around the new Via/nforce boards when they arrive. I've researched Crucial, Anandtech, and Tomshardware FAQs for info on DDR memory. From what I have read, registered memory should be used over 512MB. I also read that the unregistered is faster but you can't mix registered and unregistered memory. I don't need more than two 256mb sticks of PC2100 now. Since I don't know what board I'll be getting and how much memory I'll want in the future, would it be better to buy registered?

 

[Boonesmi]

true that amd 760 based boards dont support more then 2 dimms unless its registered, but... thats a just problem with the AMD chipset board

personally i would buy unbuffered/non-parity (its the fastest and cheapest stuff)

 

[tcsenter]

<< I don't need more than two 256mb sticks of PC2100 now. Since I don't know what board I'll be getting and how much memory I'll want in the future, would it be better to buy registered? >>

Unless you don't mind having to replace the two unbuffered modules whenever you decide to go with more RAM in the future (more than 2 DIMMs). Using more than 2 high-capacity (256 or higher) unbuffered modules increases the risk of RAM-related problems, using more than 3 is virtually a guarantee of problems, unless you use registered modules.

<< true that amd 760 based boards dont support more then 2 dimms unless its registered, but... thats a just problem with the AMD chipset board >>

Actually the problem isn't unique to any particular chipset. It is an inherent problem when a host-based memory controller has the burden of driving the clock/control signal across many unbuffered modules, regardless of chipset. Its just that AMD has been good at documenting theirs to protect users from trying to use 3 or more unbuffered modules, VIA and Intel haven't.

On Edit: After reading my post a few times, it would be reasonable to conclude I was claiming the 'two module' AMD limitation is found on all chipsets. That wasn't my intent. This specific "two module" limitation is unique to the AMD chipset. However, all boards are susceptible to RAM related problems when using more than 2 or 3 unbuffered high-capacity DIMMs. Some do not become problematic until the third slot is populated, others not until the fourth slot is populated. This is not, unlike the AMD, specifically a limitation imposed by the chipset, but for the reasons I stated above. I should have been more clear.