有沒有做Registered和有沒有做ECC沒有關係，所以會有以下四種組合：

Registered Non-ECC

Registered ECC

Unbuffered ECC

Unbuffered Non-ECC

偶只知道有第2種
貴的要死咧

第四種Unbuffered Non-ECC就是滿街都在賣，一般最多人用的那種

What's unbuffered and buffered memory?

This line tells you whether your system takes buffered, unbuffered, or registered modules. Unbuffered modules are the most common. In unbuffered memory, the chipset controller deals directly with the memory. There is nothing between the chipset and the memory as they communicate. 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 are unbuffered modules that 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.

DDR and SDRAM modules can be registered or unbuffered; EDO and FPM modules can be buffered or unbuffered.



What's the difference between registered and unbuffered memory?

Registered modules contain a "register" that helps to ensure that data is handled properly. Unbuffered or standard memory modules do not have a register. Because registered modules are slower than unbuffered modules, registered modules are generally used only in mission critical machines, such as the large servers used by corporations.

Registered and unbuffered modules cannot be mixed in the same system.



What is ECC Memory? Do I need it?

ECC stands for "error correcting code." Like parity memory, ECC memory detects and reports memory errors. However, while parity can only detect errors, ECC can actually correct errors without interrupting the other operations of your system.

If you do not see an option for ECC memory when searching for your memory upgrade, your system most likely has non-ECC memory installed and will not support ECC memory. In this case, you should upgrade your system with non-ECC memory (standard).


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Source:
http://www.ocsystem.com/whatunandbuf.html
http://www.ocsystem.com/whatdifbetre.html
http://www.ocsystem.com/whatiseccmem.html

受教了
謝謝~~