I've tried searching the forums and have even googled this a couple times, and have not come up with anything useful... but please excuse the old, somewhat outdated topic, and if something similar has already been posted, please kindly direct me there, as I've not had any luck finding it myself, and graciously accept my apologies. I have a couple questions regarding some potential RAM upgrades that I'm looking to go through in the near future with my QuickSilver G4 733 (2001 model). It currently has 768 MB of PC100 RAM, and I'm thinking of upgrading it to three 512 MB sticks of PC133 RAM, and have the following questions: 1. If I had a PC100 512 stick, and a PC133 512 stick, would the PC133 be significantly, or even marginally faster? 2. What do I have to look out for in terms of purchasing the correct RAM? I'm thinking of going the eBay route, as new PC100 and PC133 RAM is REALLY expensive through places like crucial.com and other online retailers, and Apple RAM = broke. When looking for what is compatible, I'm finding this: PC133 SDRAM (3.3V, unbuffered, 64-bit, 168-pin, 100 MHz). I think I can make sense out of most of it, except the last part... 100 Mhz. I'm a little hazy. Doesn't the PCxxx part denote the frequency? It seems like it's saying it's 133 and 100.. confused... 3. Can I mix RAM types? lowendmac.com states that my computer can take three RAM sticks, and can either be PC100 or PC133, but doesn't state whether or not they can be mixed. In the event that they CAN'T be mixed, anyone interested in three 256MB sticks of PC100 RAM? 4. 1.5GB of RAM sounds like a lot, unless you're comparing it to 16GB in the new G5. Being that my computer is 5 years old, and I'm trying to stretch it as long as I can, while still remaining reasonable, is this a worthwhile upgrade, being that it will probably cost between $100 - $150? I guess what I want to make sure of is that I'm going to see a performance increase that is significant enough to warrant dumping some cash on new RAM. For what it's worth, I do primarily some home recording studio stuff (Cubase, GarageBand), and lots of graphic design (CS2, Quark, etc.), and the typical everyday usage stuff, too. Any help would be greatly appreciated, and again, I apologize if this has already been covered elsewhere. Thanks for reading my long-winded post.