So you got two drives both 2.5", 5400rpm, SATA the only difference being the capacity 80GB and 250GB, how does just the extra capacity generate more heat, i don't understand. I could understand a difference in RPM 5400 to 7200 generate more heat because it will spin faster which also leads me on to can you put the 2.5" 7200rpm drive in the mac mini without any major Heat problems.
Larger drives tend to result in more head seeking activity, so heat levels will be affected to a small degree. Not usually by much on same-speed drives of course, and additionally on-board cache size plays a part, with larger cache reducing drive activity.
Cand these Heat problems from bigger hard drives be controlled in the mac mini by the fan in anyway?
Yes, you can run smcFanControl and increase the standby fan speed slightly, which cools the mini a little more aggressively. It would likely not be necessary however.
I've got a 250GB External Lacie mini connected via firewire which isn't or doesn't seem fast enough and my purpose is for Music Production so a faster and larger hard drive is pretty much required for that purpose.
You would only notice improved system performance if the external was not just larger capacity, but a faster (7200rpm) drive AND was also used as the system startup volume. That would give you an overall boost to performance. Swapping out the existing 5400 drive for another of the same speed but larger capacity would not give you improved performance of course.
I would like to connect the external to the SATA interface but from what i've read the mod requires a little bit of the case to be hacked for the SATA cable to come through and like i say i don't really want to hack my new Mini case, if i can get another case to hack it would be ok but i dont think you can buy the cases on there own.
There are some instances of mini casings being sold by a few suppliers and of course on ebay if you were interested in experimenting, but it's not for the faint-hearted since you'd need a full disassembly of your existing system to put it into a different enclosure. However, you might just need a casing top, which is a much easier proposition. If memory serves, the SATA modification does not need much of a casing alteration though. Not something to do if the system s still in warranty, but perhaps worth considering if it is not.
It's because of the case hack that i would rather just upgrade the internal drive to as big as i can get it without any problems which is obviously to do with heat.
Many others have had similar needs and concerns, but there is no history of issues reported here to suggest that 7200rpm drives in themselves, cause overheating issues when fitted to Mac minis. I would personally have no concern at fitting one in my systems if I had need of better speed, and I doubt a respected supplier such as OWC would include the faster drives in their list of compatibles if they had had complaints (as surely they would)!