Monthly Archives: December 2009

Memory Madness

Last summer I had a serious meltdown with my iMac G5, which forced me to make an emergency purchase of a new Mac. I ended up getting a nice 24-inch iMac from the clearance section of Apple’s website. It was about $100 less than the low-end 24-inch iMac of their current models, and I believe the CPU was a bit more powerful than the newer model.

There were a couple of areas where the older model fell short, though. One was the internal drive, which is only half the capacity of the newer model: 320 gigs instead of 640. As it turns out, 320 fits into my backup scheme (for now) much better than 640 would have, but on the other hand, that amount of space is already feeling cramped. That, however, is a whole other discussion, given the complexity of my drive/space issues.

What I am really complaining about is the RAM situation.

First, let me say that one of the appeals of the older model was that the RAM cards cost a lot less. The newer iMacs apparently use a different type of RAM, which costs 6 or 8 times as much per gigabyte as the old kind. That means if I had gone with the newer computer, I probably wouldn’t be able to afford a memory upgrade at all. However, since the newer model came already equipped with 4 gigs of RAM, I probably wouldn’t need to. The older model came with 2, upgradable to 4, and my old iMac was maxed out at 2.

2 gigs was working ok on the old computer, but since the upgrade, there have been problems. What’s more, I could not have anticipated that this would happen. (If I had, I would have bought the newer iMac.)

On the old iMac, I had three programs which were utilizing quite a lot of RAM, but the situation was tolerable. I was able to manage my usage so I didn’t do a lot of frequent switching back and forth between them, and none of my other software was particularly demanding in terms of RAM.

However, this has all changed on the new iMac. I was still running Tiger on the old one, but the new one came equipped with Leopard, and Leopard comes equipped with Time Machine. It turns out that Time Machine can be quite a memory hog itself, and since it runs automatically, once every hour, it’s not an issue that goes away. In fact, it’s a constant annoyance.

What happens is Time Machine relies on a process called “mds”, which is involved in Spotlight indexing. Basically, it’s how Time Machine knows which files to back up and which to skip over. On most systems, mds won’t take up huge amounts of RAM, but the more files you have, the more demanding it becomes. I have a lot of files, so mds is sucking up over 350 megabytes of RAM each time a backup is performed.

This is bad because it has to borrow those megabytes from other programs, which then have to grab them back after the backup is done, and this happens every hour. This back-and-forth swapping of data can seriously slow things down, if a lot of it needs to happen all at once. When I have my big memory-hog programs open, and Time Machine has recently performed a backup, I invariably have to sit twiddling my thumbs waiting for the memory swap, even on something simple like pulling up a Finder window. And then an hour later, I can look forward to it all happening again. Anyone who’s used a computer a lot knows that an hour can fly by pretty quickly, too.

Clearly I need a RAM upgrade.

So last night I ordered one. And this is the part that’s got me pissed off: My current 2 gigabytes of RAM is installed in the form of a pair of 1-gig cards, one in each of the two RAM slots in the computer. That means no empty RAM slots, so if I want to upgrade to 4 gigs, I have to buy the full 4 gigs, rather than just 2, meaning the upgrade costs twice as much as it ought to.

The final bill for this RAM upgrade, not including sales tax, comes to just over $100. In other words, the money I saved by getting the older computer has been entirely eaten up by having to upgrade the RAM to equal what the newer computer would have had, and of course the hard drive is still only half the size. So I ended up with a lower capacity computer for the same amount of money! Obviously, I should have skipped the fucking clearance model and just got the newer computer!

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Filed under annoyances, computers