[abbaZaba]

I am thinking about replacing the 80GB hard drive in my mac mini with a 320GB version, but I have two questions:

1) can/should I go for a 3.0Gb/s SATA interface? the stock HD only has 1.5Gb/s and I don't know if getting a 3.0Gb/s would cause incompatibility.

2) will getting a 7200RPM drive cause heating issues? I read somewhere that due to the mini's design, choosing a 7200RPM drive would cause heat issues and the preferred choice would be 5400RPM.

I have the 1.83GHz Core 2 Duo version.

[mduell]

1) Some drives have issues with 1.5Gb/s controllers when they're set for 3Gb/s, but they have jumpers you can move to work with 1.5Gb/s controllers.
2) No, the power consumption doesn't differ much (tenths of a watt).

[Simon]

Yep, the 7200 rpm drive won't be a problem in your mini. You'll like it.

Just remember that depending on the amount of data you put on a drive, the drive with the faster spindle speed might not be the actually faster drive. Since you're coming from an 80 GB HDD I guess you're not expecting to put more than 250 GB on it, but if you are, you might want to reconsider. A 320 GB 7200 rpm drive filled up to ~250 GB will be slower than a 500 GB drive at 5400 rpm. Just make sure you think about how much plan on putting on that drive before you buy it.

320 GB 7200 rpm HDD for $90 at Newegg. They also have one for $80 after rebates.
500 GB 5400 rpm HDD for $120 at Newegg.

(there's more, these are just the least expensive)