Memory: Registered or Unbuffered? 3

[steve2540]

What is the difference between unbuffered and registered memory?
Does it make a difference in performance?
Can you use either in all motherboards or does the motherboard need to support registered memory?

Thanks,

 

[kippy13]

http://groups.google.ie/groups?hl=e...0l4ck2h8mi5o4bmmnl8e78klpm7o%404ax.com&rnum=1

This is a huge thread which I am sure will answer your question.

"Sometimes I do not know but I try hard"- R.F. Haughty 1923

 

[cdogg]

The link does mention unbuffered vs. registered, stating that not all motherboards support it and you shouldn't mix them. Going into more depth, registered memory offers parity error correction. Parity does not necessarily increase a system's speed, but instead improves its stability and efficiency. However, this improvement is hardly seen in a desktop system. Normally, you would only want to use it in high-end systems like servers in order to gain any benefit from the extra cost.

~cdogg
[tab]"All paid jobs absorb and degrade the mind"
[tab][tab]- Aristotle

 

[Freestone]

Here are some Q & As from Crucial's site:

http://www.crucial.com/kb/KBSearch.asp?SearchTerm=registered&Category=

What is the difference between buffered and registered memory?

DDR and SDRAM can be unbuffered or registered. EDO and FPM can be buffered or unbuffered. Buffered modules contain a buffer to help the chipset cope with the large electrical load required when the system has a lot of memory. Registered modules do not have a buffer but do contain a register that delays all information transferred to the module by one clock cycle. Buffered and registered modules are typically used only in servers and other mission-critical systems where it is extremely important that the data is properly handled.

What does "registered" SDRAM mean?

The term "registered" refers to how the memory module processes signals. Registered modules contain a register that delays all information transferred to the module by one clock cycle. This type of memory is primarily used in servers and was designed for modules with 32 or more chips on them to help ensure that data is properly handled.

While most PCs will accept only unbuffered SDRAM, there are some that accept registered SDRAM. Keep in mind that when you install registered SDRAM, all of the modules installed in your PC must be registered because unbuffered and registered modules are not interchangeable.

You can tell if you are using registered memory by looking at one of the modules currently installed in your system. If it has one or more small black chips mounted horizontally on the module, you have registered memory. If not, you have unbuffered memory.

If you are not sure whether your motherboard or PC supports registered SDRAM and it is not listed in our Memory Selector, please e-mail us at crucial.support@micron.com. We would be happy to look into it for you.

Is unbuffered memory faster than registered?

Yes, unbuffered memory is faster than registered memory. The register in registered memory delays all information transferred by one clock cycle, slowing the overall system performance.

Most systems are designed to take either registered or unbuffered memory, and the two are not interchangeable. If your system takes registered memory, it probably won't work if you try to replace the registered memory with unbuffered memory.

Is all registered SDRAM also ECC?

Yes and no. Registered SDRAM does not necessarily have to be ECC. However, at Crucial, we've found that our customers who purchase registered SDRAM also want ECC. As a result, all of the registered SDRAM we sell at Crucial.com is also ECC.