Dual Channel memory

[jussi]

I just got a computer case and I'm canibalizing an older computer for parts. According to the specs the new case uses Dual channel DDR memory. In fact here are the specs. http://www.clipclip.org/clips/detail...-mini-barebone

As I understand it Dual Channel memory is where 2 identical sticks of ram are used. The 2 sticks I got from my older comp are not identical, does that mean I can't use them. Can I just use of the sticks then?

On a side note, anyone know a good place to get a deal on a low profile power supply?

[LinuxRandal]

Non identical sticks CAN (empasize CAN) still support dual channel, but not always will.

If they are the same speed, and latentcy you have a higher chance. Different brands, with the same brand chips on them improves your chances some more.

While I haven't seen any non servers require dual channel, I haven't seen every motherboard. Most home pc motherboards will work in single channel mode, if dual channel not detected. My current pc I am on, is an older AMD 64, 4000 that I used some old slower ddr (266?) memory and the sticks were the same brand (but sold individually, not as dual channel). They are seen and work as dual channel in my system and using the old sticks I brought it up to 2gb, before that was common.

[BobSch]

Here's an article on dual channel DDR RAM

http://www.hardwaresecrets.com/article/133

From page six of the article:

To use DDR Dual Channel configuration in order to achieve the maximum performance your CPU is capable of giving you, you will need a motherboard with this feature and two identical memory modules.

[jonmulzer]

You can also usually (that's the key word there) get dual channel to work when you are able to go into memory settings and set it to the slowest timings from each stick. It is a complete PITA though unless you have easy access to complete specs. Also your motherboard has to support these options. Dual channel on DDR was only showing a 3-5% gain in synthetic benchmarks if I remember correctly. You are unlikely to notice in real world use unless you are really taxing your system, IMHO.

Memory is cheap though. NewEgg has 2GB of DDR400 memory in a matched 2x1GB set for $85. That is about the same price I paid for 2x512MB a few years ago when I built my last AthlonXP system.

[rjwaldren]

There are several ways it could go and alot of it depends on the board and it's bios. Install them and see what happens. Most times if two sticks won't work at their rated spec in Dual Channel it will fall back to the next one down (ie fails at DDR400, but works fine as DDR333). Most but not all bios' should give you at least that level of control, many will let you play with individual timings to find the optimal settings for the sticks to work together at the fastest possible speed.

If it fails to work in dual channel it may still be usable at the full capacity of the sticks, it will just be slower. Whatever you do beat it up with Memtest86+ before moving forward.

[BobSch]

Memory is cheap though. NewEgg has 2GB of DDR400 memory in a matched 2x1GB set for $85. That is about the same price I paid for 2x512MB a few years ago when I built my last AthlonXP system.

This is just a personal opinion, but... Friends don't let friends buy cheap memory.

Try http://crucial.com or http://kingston.com. Prices aren't that much more than the cheap stuff and you'll have fewer intermittent, hard-to-trace, problems.

[jonmulzer]

This is just a personal opinion, but... Friends don't let friends buy cheap memory.

Try http://crucial.com or http://kingston.com. Prices aren't that much more than the cheap stuff and you'll have fewer intermittent, hard-to-trace, problems.

$85 buys you G.Skill, a brand I trust for the most part. Admittedly not as much as my brand of choice (Mushkin), but not no-name either.

[rnelson0]

NewEgg has 2GB of DDR400 memory in a matched 2x1GB set for $85.

Staples has a 2GB (2x1GB) kit of DDR2 PC5300 (667MHz) from PNY on sale for $54 and some change. I got it last night and aside from the RAM being a surprising blue, was exactly what I wanted. You can order it online or get it in the store, whichever is easier. Deal runs until 2/23.

[jussi]

Thanks for the advice guys. I'm going to try the memory I have and see if it works, if not I guess I'll have to spring for new ones.

Thanks rjwaldren for the tip on using Memtest86+. I hadn't heardn't of the program before. Looks interesting and very useful.