Two 2GB sticks, or one 4GB?

April 20, 2009 5:44 PM

Which is better, one 4GB stick, or two 2GB sticks of DDR2 RAM in my Laptop?

I bought a new laptop with two 800Mhz DDR2 slots. I saw a good deal on two matched 4GB DIMMs (8GB total), but I think because I'm running Vista 32bit, I can't put in more than 4GB. :(

So should I get a matched pair of 2GB sticks, or a single 4GB stick?

posted by brenton to computers & internet (8 comments total)

The advantage of the single stick is that it leaves a slot open for future expansion, which may come at a time when you're running an OS that can handle more than 4GB.
posted by allen.spaulding at 5:52 PM on April 20

It's probably dual channel, so two sticks of 2 gigs will actually, I believe, run faster than the one 4 gig.
posted by Geppp at 5:57 PM on April 20

Two sticks are technically faster than one - you can measure the speed difference using performance testing software, but it's not strictly something you'll notice during daily use - so it's a better idea to go with two 2GB sticks...unless the machine is beefy enough to possibly potentially upgrade to either 64 bit Vista or an upcoming OS that handles over 4GB.

It really depends on what your future plans are.

I personally would go for two 2GB sticks. Even if it gets to the point where I can have over 4GB, I'd just swap out one of the sticks and put in a 4GB or whatever, which is perfectly kosher. I'd lose the performance that I wasn't really noticing anyway, but I'd have more RAM, which would more or less cancel out the performance loss.
posted by turgid dahlia at 6:20 PM on April 20

faster*
not faster. Yes in benchmarks you will see an improvement. No you will not notice in any normal computing task. Get whatever is cheaper / easier. Don't forget, you will only actually see about 3GB anyway, since the rest of the address space is taken up by your other stuff. (PCI Bus, etc.) 64 bit vista is fine by all accounts, not like 64bit XP.
posted by defcom1 at 6:21 PM on April 20

"Benchmarking software" is the expression I was looking for and failed to find.
posted by turgid dahlia at 6:24 PM on April 20

If you're able to get a good deal on more RAM than you think you might ever conceivably use, take it up. Fit the 8GB.

It's perfectly true that you won't ever use more than 3GB of that if you're running a 32 bit OS. However, in four years two things will have happened: you will be looking for ways to make your laptop run a bit quicker because it will be suffering from four years of Wirth's Law; and RAM will have moved on a couple of generations from DDR2, making it very expensive to retrofit the machine with enough compatible RAM to deal with your new expectations of it.

If you wedge in as much RAM as you can right now, then in four years all you will have to do is install the 64-bit OS du jour and you'll be good to go. And even if you decide to upgrade your whole computer, today's large DDR2 sticks will probably sell for more than you paid for them (standard sticks will be throw-away jellybeans).
posted by flabdablet at 11:56 PM on April 20 [1 favorite has favorites]

Re: "If you're able to get a good deal on more RAM than you think you might ever conceivably use, take it up. Fit the 8GB."

Won't the extra 4GB tend invariably to be cheaper by the point at which you'll actually need it? If so, get the 4GB stick, then upgrade years later with another.

The more important thing, though: are you sure that each slot can handle more than 2GB and/or that your motherboard can handle more than 4GB total? (Since Windows can't support more than 4GB, would it not be rather rare that manufaturer's of machines with a relatively short life-span would go out of their way to support more?)
posted by astrochimp at 9:37 AM on April 21

Won't the extra 4GB tend invariably to be cheaper by the point at which you'll actually need it?

Absolutely not.

By the time you actually need another 4GB of DDR2, DDR2 will be about as expensive as PC133 is now.

DDR3 already exists and is well on the way to becoming the standard technology for new boxes. DDR3 sales volumes are therefore trending up, and DDR2 volumes trending down. DDR2 is not going to get significantly cheaper than it is right now.

So you're better off putting as much RAM in your mobo as it will take, and making use of the slight speed increase you get from running multiple sticks in dual-channel, even though you won't be using anywhere near the full capacity until you install a 64 bit OS.
posted by flabdablet at 12:17 AM on April 23