Do I need to add RAM in matching pairs?

November 12, 2006 4:33 PM

Do I have to add RAM in matched pairs to my dullard of a Dell Dimension 110? I've gotten conflicting information and don't know who to believe. I need to finish this post haste to meet a client deadline and I'm freaked at the prospect of ruining my computer, dismal as it is. I've got 256 and I'm trying to add another 100.
posted by wordswinker to computers & internet (8 comments total)

Do you mean 1100? If so, then Crucial says: "# Slots: 2 (2 banks of 1). Although the memory can be installed one module at a time, the best performance comes from using matched pairs of modules."
posted by raf at 4:39 PM on November 12, 2006

It's a B110, not an 1100, and it's just a few months old. I'm having a hard time deciding if what I'm adding is DIMM, if so, the manufacturer said it doesn't have to be a matched pair in any computer with Pentium. Oy. I do not like this one little bit.
posted by wordswinker at 5:14 PM on November 12, 2006

You should open it up, and see what you already have, as a first step. If you have 256 MB, it could be organized as 2 DIMMS of 128 MB each, filling both of your DIMM slots. In that case, to add memory, you are going to have to get rid of one or both existing DIMMS. In that case, your minimum best bet is probably a couple of 256 MB DIMMS, which will get you to 512 MB of memory. But your machine probably is using 32 MB of the main memory as shared video memory, meaning if you have only 256 MB now, you actually only have 224 MB available to the system and applications, which is very, very little for a Windows XP system. [You can check this by going into Control Panel --> System, and seeing what the memory amount is at the bottom of the control panel.] So you probably wouldn't have more than 480 MB available to the system and applications at the 512 MB level, which is a much better situation than you are in now, but still pretty tight if you use several programs at once. You could also put in 2 512 MB DIMMs for a 1GB memory pool, and have enough memory to run several applications at the same time, without paging out memory to disk constantly. You'll see and feel much, much better performance at this point.

256 MB DIMM modules from Dell are selling for about $47, but you can find PC3200 type memory elsewhere for a few bucks less. Probably not really worth shopping around too much, unless you are buying other stuff, and getting a deal on shipping, too.

It's possible you also have 1 piece of 256 MB DIMM, and one empty DIMM slot, 128 MB DIMM sticks being fairly uncommon these days. If that's the case, put another 256 MB DIMM in the empty slot. Keeping the memory in matched bank pairs (same kind and capacity of memory modules in both slots) allows the memory to be addressed in interleaved mode, which is potentially somewhat faster for memory intensive operations.

You can use Dell's Web site tools to check your configuration, and order memory.
posted by paulsc at 5:56 PM on November 12, 2006

Ah, for the B110, Crucial says: "# Slots: 2 (2 banks of 1). Although the memory can be installed one module at a time, the best performance comes from using matched pairs of modules."

So yea, you just need to add a single module. I wouldn't add a 128, though, since that's tiny these days.
posted by raf at 6:07 PM on November 12, 2006

From a quick search it looks like this model uses DDR, so that means you don't have to pair them but you might get a performance boost from having matched pairs (same size and timings) which would enable dual-channel mode. It will depend on the chipset.
posted by Rhomboid at 6:11 PM on November 12, 2006

By the way "DIMM" refers to the packaging, not the kind of RAM. There's "plain" SDRAM, DDR SDRAM, DDR2 SDRAM, DDR3 SDRAM, and so on, all of which would be referred to as "DIMMs" even though they use different incompatible sockets.
posted by Rhomboid at 6:15 PM on November 12, 2006

Also, you're probably not going to "ruin your computer" by plugging the wrong thing in. unless you plug it in with a hammer. Worst case: you put the new memory in, the machine fails to start, you take the new memory out, and you're back to normal. No need to freak out.
posted by xil at 6:20 PM on November 12, 2006

Thanks everybody! I got it installed, got Photshop up and going, and it's running like a rabbit. Well done. xoxo
posted by wordswinker at 7:01 PM on November 12, 2006