RAM terminology

[nomadics]

I am wanting to buy more Ram, but dont understand the terminology.

The cheapest RAM module has this info:
# odule Size: 512MB
# Package: 184-pin DIMM
# Feature: DDR PC2700
# Configuration: 64Meg x 64
# DIMM Type: UNBUFFERED
# Error Checking: NON-ECC
# Speed: DDR333
# Voltage: 2.5V
# Memory Timings: CL=2.5

And the most expensive one this:
* Module Size: 512MB
* Package: 184-pin DIMM
* Feature: DDR PC2700
* Configuration: 64Meg x 72
* DIMM Type: REGISTERED
* Error Checking: ECC
* Speed: DDR333
* Voltage: 2.5V
* Memory Timings: CL=2.5

What does the difference in Configuration, DIMM type, and Error checking mean?

[Platypus]

Hi nomadics. Not to be too complex, the Registered ECC memory with the 72 bit configuration, has a very high data integrity like would be used for server applications, and needs a system board that can use Registered ECC DIMMS. ECC is Error Checking & Correcting, the 72 bit configuration simply means the memory has an extra "bit" available for each "byte" and this is used for the checking.

The cheaper memory is normal sort of memory used in regular consumer systems, and if it's reasonable quality, works fine.

[nomadics]

HI thanks for that Platypus. The prices between different brands also varies a lot, is there anything else I should be looking out for?

[Platypus]

The computer market is very competitive, so in many cases the simplest rule is "you get what you pay for". If something is very cheap, there's a reason. Unfortunately it doesn't always work the other way, something very expensive might just be a rip-off!

Many people like to use high grade suppliers like Crucial, Kingston, Corsair or Mushkin, very good warranties can be one sound reason to go this way. The memory can also have superior specifications for overclocking etc.

I've not had any trouble using what might be called generic memory. I buy what I need from a supplier here in Australia that I've found reliable and he just avoids the el-cheapo sources and gets ones made with chips from reasonable manufacturers like Samsung (who are big in memory fabrication but not expensive).

[confus-ed]

..I've not had any trouble using what might be called generic memory. I buy what I need from a supplier here in Australia that I've found reliable and he just avoids the el-cheapo sources and gets ones made with chips from reasonable manufacturers like Samsung (who are big in memory fabrication but not expensive).

Same here (not in Australia obviously ), finding a good supplier with decent return policies & warranty even on 'generic ram' can save you tons of cash on bulk system builds as well as day to day , however imho you need to be 'sure' about this policy with ddr400 .. which brings me neatly to :-

is there anything else I should be looking out for?

Check the ram speed, & the timings match (the speeds your board can run ) "Speed: DDR333 .. Memory Timings: CL=2.5 " - sometimes these get quoted in different ways - & that's what 'pc2700' & 4-3-3-2 etc (like it may say in your m/b mannual) are about ... also check your board supports this big a memory module, I'd have thought so - but maybe not

& You are matching this to same specification memory ? I'm just thinking that if you have to ask about this new, then you maybe won't be too sure about what you've got either ? - speed differences between what you've got & intend to get, may make no difference (everything may run at the slowest speed) however sometimes infact many times it means no-go !