I thought I would provide a few tips for upgrading the 2009 Mac Mini, which some guides don't cover fully. If you plan on upgrading yourself, doing any damage inside can void your warranty. There are actually no stickers inside that you have to break to change the RAM or HDD and I didn't find it to be all that bad. If you're not sure about it, pay an Apple Certified Tech to do the upgrade for you but then you won't save much money.
Apple's upgrade prices on the Mini are quite expensive so this can save you some money.
The base Mini is 2GHz Core 2 Duo for £499. The 4GB Ram upgrade costs £120 and a 250GB 5400rpm drive is £80. This takes us up to £699.
What I did was upgrade to 4GB Ram and a 250GB 7200rpm drive for £630 plus I can get £50 back, which I'll explain so overall £580
What you will need to do first of all is buy your upgrade parts. I opted for 4GB RAM (check Crucial for the right kind) and a 250GB 7200rpm Hitachi Travelstar hard drive (they are supposed to be quieter than Seagates and I can verify they are pretty quiet). I also got a cheap Mac compatible 2.5" SATA enclosure from ebay for under £10:
drive = £63
RAM = £56
drive enclosure = £10
total = £129
When you get all the parts, put the drive into the enclosure and plug it into your new machine, which you should have setup (don't setup Bootcamp yet though). Format the external drive as GUID partition map (important!) and HFS+ Extended Journaled with disk utility. Download Carbon Copy Cloner (CCC) or SuperDuper - I used CCC - and clone your internal onto the external drive. It should take about 15-20 minutes.
Reboot the machine holding alt (the alt-key on the new keyboard works finally) and make sure you can boot from the external drive.
Now shutdown the computer and remove all peripherals and power leads. Touch some metal objects to discharge any static.
To open the Mini up, you need the stupid putty knife method - the person who designed this case is a complete idiot. The knives have to be extremely thin and you'll find that pulling one edge up makes it very difficult to use the knife on the other side. Some Minis are easier to open than others but it kind of seems like they've strengthened the metal this time round as I found it harder than the last generation. The top case also feels heavier.
Anyway, once you have it loose, lift the top cover straight up and off. You will see the following:
There are 3 antennas. In the Mac Mini Colo guide, it shows the antenna wires disconnected from the motherboard. You don't have to disconnect these and you actually can't until you flip the top over anyway.
It's actually easier to take the top of this one than the last model.
You take the airport chip off same as the last generation by squeezing the black plastic clips underneath it - hook it over the back of the machine out the way. This allows you to access the screw at the back. The screw locations are marked with a circle above and there are 4 you need to remove. The long one goes into the front right in case you forget where it came from.
There is an orange data cable at the back. I disconnected it from the back of the optical drive rather than the I/O board as it's easy to get your fingernail in and gently prize it off. Be careful not to squash it though when moving the top part that you remove.
Gently lift the top part directly upwards. When it's loose, tip it over in the direction indicated in the image. If you're facing the front, it tips over to your left. The two antennas still have wires attached - as I say, you don't have to remove these.
I should have taken a picture of this but you'll see the bottom part looks like this:
The RAM is easy to remove. You just push out the two silver clips one each side. One thing that I noticed here was that the base Mini only gives you a single 1GB module. This probably reduces the performance of the graphics as it's not matched memory. Slotting the RAM in should be fairly trivial if you've replaced RAM before. Just make sure it snaps firmly into place. If you think you are straining it too much, try pulling the sliver levers to get the modules in.
That's the RAM upgrade done.
The hard drive is actually pretty easy to replace too. It's underneath the following block and you will see it clearly when this is upside down:
It's held in by 4 screws. There is a wire glued and taped to it. Don't worry about this as you can put it back onto your new drive easily.
The wire has a tiny chip glued to the front of the drive. You can ease this off with a small flathead screwdriver. Try to leave some glue on it so you don't have to tape it. Remove the tape too and push the wire out the way.
Take out the 4 screws and the drive will slide right out. It's not tight.
Take the drive out of your enclosure and put it in. There are no drive jumpers to worry about. Screw the drive in place and tape the wire back down. If the chip still has enough glue, it should stick back on quite firmly. If not, just add a little piece of tape over it. I think it's just a heat or vibration sensor.
There are also 2 sticky pads on the other side of the drive for cushioning. Transfer those over too. They help when slotting the drive back in.
Now that's the drive installed so flip the top back over into place and be careful not to damage the orange data cable. You also have to align it properly so that the chip on the bottom drops into the slot. It's not too difficult but do it gently.
Connect the orange data cable back up.
Connect your display, power and keyboard/mouse and boot the machine to check everything is ok. Go into the system profiler and check the RAM shows up ok. If it's working fine, shut down and disconnect everything again.
Put the 4 screws back in and then put the airport back on (remember the spring).
Now just clip the top cover back down and you're done.
The hardest part IMO is dealing with the top cover. 4 screws would make the whole process so much more pleasant.
Now, the savings I was talking about. When you take the internal 120GB 5400 rpm drive out, you can put this back in your enclosure and sell it on ebay for about £35-40. The 1GB module that was in it, you can sell for about £10-15. I'm personally going to keep the external as another backup drive (you can use it for Time Machine for example).
As far as the performance goes, getting the 4GB RAM is a good thing. It's cheap and you can't upgrade beyond this. The 7200 rpm drive I wasn't sure about at first. I did some benchmarks before I did it though and it seems that the 5400rpm drive in the new Mini is faster than the old one. I actually got double the performance. I'm not sure if they use drives with a higher density or something so I wondered if I actually needed 7200rpm but it was also double the space so I decided that if it was quiet enough, I would go ahead with it.
In the external enclosure, it sounded noisier but inside the machine it's actually fine and it doesn't seem to generate much more heat than the 5400rpm. It is a touch noisier but from a distance of about 2 ft, it's still pretty much silent.
I also did some benchmarks before and after and I noticed a distinct 25% performance improvement in drive writes - booting is also faster. I tested both writing a large single file and 10,000 x 100k files. Both showed a 25% improvement consistently.
Also, once you install more RAM, your VRAM goes up to 256MB on the 9400M. Using two modules should also help improve graphics performance. I have the Call of Duty 4 demo so I'll let you know how it runs on this machine.
For the price of £580, even though PCs are around that for a Core 2 Quad, the RAM, HDD and graphics are about even. I would prefer it to be £480 but the economy does play a part in this. If you have an old Mini already, you will get about £300 for it so it's a £280 upgrade cost and well worth it for the graphics alone.
I have also Bootcamp'd the machine (had to get another SP2 disc as I got the disk error, press to restart issue - you need one with the formatting option on it and choose FAT or NTFS quick) and you insert the install disc that comes with your machine for the drivers. So far, the graphics performance seems to be on par with the X1600 in the old iMacs but that was before my upgrades.
No graphics glitches are present so far that existed on the Intel one.