What are the advantages/disadvantages to PC2100 DDR - ECC registered & the unbuffered

After taking a look at the types of DDR SDRAM available, I woder if my descision to go with 2 x 256MB PC2100 ECC Registered CL2.5 184 pin DIMMs to go with my Gigabyte GA-7DXR mobo...is there any real difference with the cheaper variety of the PC2100 type memory?

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AMD Athlon 1.4GHz
Gigabyte GA-7DXR
512MB PC2100 DDRAM
Hercules Prophet III
Dabs 15.1" TFT DVI
Hercules Gamer XP
VideoLogic DigiTheatre DTS
2 IBM Deskstar 60GXP 20GB
Mirai 40-16-10 SCSI CDRW
Pioneer 10X 40X SCSI DVD
Cooler Master Aluminuium 201 case w/400w PSU

Rather than plagiarize I will just give you this link... Crucial has a pretty good FAQ that answers all your questions and more...
http://support.crucial.com/scripts/crucial.exe/faq

But, basically ECC memory is a little bit slower and not really necessary unless you are setting up a server. In the desktop world it's pretty much over kill. (and it does slow your system down just a tad.)

If you get registered memory and your board supports it you can put more than two PC2100 DIMMS on it. If your board only has two DIMM slots as the ASUS A7M266 does then there is really no need to buy registered.

[This message has been edited by cygnus (edited June 22, 2001).]