I'm wondering if all the labor would be worth it. I've looked up the hard drive model in my eMac. It's an 80GB 7200RPM drive with 2MB cache buffer. My question is 2 fold. I remember hearing about the older macs having a threshold of drive space they would support, like 100GB or 120GB. But I wasn't sure if that was OS limited or hardware limited. My eMac is currently running 10.5.8. Presuming that it is only a OS issue, then my 250GB IDE/ATA drive I bought in error should work. 2nd question(s). The 250GB drive I have is also 7200 RPM, but obviously newer, and has a 16MB cache buffer. Upgrading an eMac hard drive is rather labor intensive, but it can be done. Am I thinking right, that since they are both 7200 RPM drives that I'm not really going to see much of a difference? Will the 16MB buffer make a night an day difference? Since the current drive is not failing, would I be better suited putting this in an external USB 2.0 housing and use it that way?