One of my 2GB Corsair memory chips let go. I tried pulling them out and putting back in one at a time. One chip came up with "Hardware problems" when MS Memory diagnosis was run at startup. Can I use a 1GB chip (Win7 only uses 3 GB) in the same channel or do I need to buy another (same type) 2GB? I don't see single chips for sale - these came in a set of 2-2GB chips.

Hi mp3guy Welcome to D-A-L

You can run with 2GB stick in one slot and a 1GB stick in the other.
So long as both stick are the same type.
If the 1GB stick is a slower speed than the 2GB then then the PC ram speed will revert to the slowest speed.
The real disadvantage with running with less memory(Ram) is, loading and running programs will
be slower.
If you don't see single chips for sale - these came in a set of 2-2GB chips.
Perhaps you could use this opportunity to buy some faster memory(ram) sticks and give your
PC a small performance boost. If your budget can run to the extra amount.

Jim

I don't see single chips for sale - these came in a set of 2-2GB chips.

The 2-packs are sold for "Dual-Channel" configurations, now supported by many motherboards. Triple packs are sold for motherboards that support triple channel. Today, they are packaged together more for convenience (and it is cheaper for the maker) than necessity.

The standard for dual (or triple) channel architecture does NOT call for identical RAM modules, but it does call for modules with the same specs. When dual channel was first implemented, some motherboards had problems unless the modules where precisely matched so RAM makers [reportedly] would test and package "matched" pairs to ensure compatibility.

Later motherboards (chipsets) are much more tolerable with RAM modules not being precisely matched so you should, in theory, be able to buy a stick from Kingston and one from Crucial, and if the same specs, they "should" work fine in dual-channel mode. But theory and real-world don't always see eye-to-eye so buying from the same maker is typically recommended by motherboard makers.

Bottom line here is unless your motherboard is very old, it probably supports dual-channel and buying an identical replacement should allow you to run in dual channel mode. But, if you decide to buy another module, the computer should still work fine, but you may not be able to take advantage of dual channel - and performance may take a hit.

Thank's much for the info... Will probably try to 'match' the good 2GB chip. Think I'll check with Corsair and see if I can get anywhere with this bad one, but it's out of Newegg's warranty. Again, thanks for your help.