Upgrading RAM on iMac DV 2000

what do you have in there right now? If you have 512, chances are you probably have two 256 meg chips, so to upgrade to one gig, you'd need to replace both chips to 512 meg chips.

OS X loves ram, the more you have, the smoother things will run, especially when running multiple programs at once. If you're doing fairly basic things, I doubt you'd see a huge difference though.

Both slots are filled, so I'm guessing it's two 256 MB chips. I'll definately look into getting some 512 MB chips, as I will be using this computer to do a lot of graphic stuff in the future.
No, don't. The performance increase going from 512MB of RAM on an iMac to 1024MB of RAM on an iMac is going to be marginal. I have an equivalent machine (G3/400) that I have upgraded with FREE RAM and it's running OS X 10.2 and it's still slow as ****. Especially for graphicsy stuff. It is slow because the processor is the bottleneck at this point. I use the machine for a server, and barely touch the console because it is so painful to use compared to my G4/Mini (also with 1GB of RAM).
Considering how much you will spend on that legacy RAM (it'll be expensive, because they are no longer produced, and you will have to buy them from a stock hoarder or from someone who has them sitting around; and the ones that have been sitting would be of questionable quality). You don't want to mess with eBay RAM 2nd hand. Kernel panics and the like? Crappy RAM is for PCs which are more fault tolerant about their hardware. It's not worth it. Save the $300 you'll spend on legacy RAM chips and put it towards a new Mac Mini.

In case you are wondering how I get FREE RAM: I take them out of PC's that are being scrapped. In my G4 I have 4x256MB not 2x512MB. And why can't you do the same? Because iMac requires high density, low profile chips which the PC's do not use. The PC SDRAM modules are too tall for the iMac's short RAM slot.

" Considering how much you will spend on that legacy RAM (it'll be expensive, because they are no longer produced, and you will have to buy them from a stock hoarder or from someone who has them sitting around..."

You can find plenty of new PC-100 or PC-133 SDRAM from reputable memory dealers. For the iMac DV, this dealer carries 512 MB PC-100 CL2 DIMMs for $75.00. At $150 for a pair, I'd have to agree that the performance gain would not justify the expense.

As for using (non-ECC) "PC" SDRAM in a Mac, I've got two 128 MB PC-100 CL2 (low density: 64 Megabit chips) DIMMs taken from a PII and a PIII, in the iMac G3/400 that I'm using right now. This slot-loading iMac can also use high-density (256 Megabit chips) SDRAM, such as a 256 MB DIMM with 8 chips or a 512 MB DIMM with 16 chips. Unlike the older beige G3 desktop models or early iMacs, it has no clearance issues related to DIMM height.

Is this a RAM that would possibly work?

http://www.circuitcity.com/ssm/Kingston-Technologies-512MB-DDR-SDRAM-Notebook-Me mory-KVR133SO-512R-/sem/rpsm/oid/108884/catOid/-12993/rpem/ccd/productDetail.do

Peace.

No, your 333 Mhz tray-loading iMac uses 144-pin PC-66 SDRAM SO-DIMMs, not PC-133 DDR SDRAM. You can compare prices for memory with those specs at RamSeeker.com, or check out this dealer's prices for comparison purposes.