First off i want to say im so happy with my 500gb seagate momentus 7200.4. I have had 2 now, the first one I got and I liked it but someone convinced me to return it and get the Hitachi 7k500. When I got the Hitachi I noticed it used a small but significant more amount of battery, it was louder at idle (wooshing sound 24/7, where the seagate was silent.) And it also ran about 6-10 degrees F hotter than my seagate. So after having both I decided to switch right back to the seagate and I couldn't be happier. This seagate has been working excellent, very quite, no noticeable drop in battery, and it's fast as hell. 19-21 sec boot time here, that's in combo with 4GB of RAM. If you produce music or edit pictures/video I seriously recommend getting this 7200RPM HD and 4GB, it helps wonders. It really lets your cpu shine, instead of bottle necking it like 2GB of RAM and 5400RPM HD do But anyways, if you get a new hard drive, I recommend you install hdapm to keep your load cycle down and to avoid clicks if you have them. OSX likes to really rack up the load cycle counts, thus diminishing the life of your hard drive. OSX or some hard drives in general constantly spin down and park the heads of your drive, and then spin back up a second later. This causes a beach ball for a second or two and does shorten your hard drives life. They do this to save power, but it only saves power if you are not using your computer. So what hdapm does it makes it so the drive doesn't spin down, but you can set it to spin slowly. If you install smart utility and check your load cycle count, you will probably notice your load cycle count of your hard drive is close to 10k after about a month. That is just too high. Hdapm keeps your load cycle way down. My first seagate was up to 10k after 3-4 weeks, as well as the Hitachi. I've installed hdapm on this hard drive and im at 1200 load cycle count after about 7 months. Which is great considering the drives are supposed to be good until 600k. Here is an article that explains further in why you should use hdapm, and it also has some useful information in the comments http://dougitdesign.com/blog/2009/12/mac-clicking-hdd-hard-drive-noise-hdapm-html/ Now I have made a full instruction list on how to install hdapm. I initially had trouble getting it set up as well. But I kept trying different things from different websites and I found a way that works, and also other users reported back to me with positive results. 1. download hdapm - http://mckinlay.net.nz/hdapm/ --------- 2. show hidden folders. in terminal enter "defaults write com.apple.finder AppleShowAllFiles -boolean true;killall Finder" (without the quotes) --------- 3. make folder. in terminal write "sudo mkdir /usr/local/bin" (without quotes) then hit enter, and enter in your password. this makes the folder hdapm must go in (usr/local/bin) --------- 4. double click the hdapm that you downloaded, and copy the actual program not the .plist and paste it in usr/local/bin. you can find the folder in finder just click your hard drive -> usr -> local -> bin. paste hdapm in there. --------- 5. find library/launchdaemons. paste the .plist in there. --------- 6. in terminal enter "sudo ~/hdapm disk max" (without quotes) - this sets your disk to max settings and keeps the load cycle down. i set mine to 200 instead of max. i forget how i did that but if you want to do that i can find out. --------- 7. in terminal type "sudo cp ~/hdapm /usr/local/bin/" (without quotes) enter. then type "sudo cp ~/hdapm.plist /Library/LaunchDaemons/" (without quotes) enter. - This will run hdapm every time you boot. --------- 8. in terminal type "hdapm disk0 max" - it should say success. this means hdapm is now usable. --------- 9. restart your mac. when your booted up. open up console. spotlight -> search console. in console search hdapm. hit enter. it should say something like disk success disk set to max 0fxe. if it says success your good. --------- 10. if you dont get success in console after the reboot do this... In terminal enter "hdapm disk0 max" enter in terminal "cd /Library/LaunchDaemons/" (without quotes) press return type "sudo chown root:wheel hdapm.plist" (without quotes) press return. type your admin password and press return - i recommend doing step 10 anyway because sometimes mine wasn't working when i rebooted, this step made sure hdapm loaded every boot --------- 11. reboot, search hdapm in console and see if you get success. --------- 12. hide hidden folders. in terminal enter "defaults write com.apple.finder AppleShowAllFiles -boolean false;killall Finder" (without the quotes) --------------------------- Now watch your load cycle and start/stop count slow down dramatically. Also as I said above i like to run my disk at 200 instead of max which is like 288 I think. At 200 it still keeps your drive from aging and acting up but it doesn't run at max power, thus using more juice. let me know if you have any problems.