I went through a period, years ago, of talking about it and people dismissing the idea (back then, my only options were to run it as a Linux box, as the very low spec motherboards available couldn't run OS X) but since then there are the NUC computers, the Gigabyte Brix computers, all with tiny motherboards with compatible parts. What has put me off is the price to performance ratio. On one hand, Apple's upgrade of the new Mac Minis has left people complaining about the CPU performance of the new models compared to the 2012 models. I thought frustrated people would be clamouring to gut their old Mac Minis and put faster performing innards in them from NUC computers. I started looking at the more powerful Brix models with Iris HD 5200 graphics.
They are about an inch taller than our old G4 Mac Mini cases. I don't have measurements for the internals but they have a large heat sink with a fairly large slot fan on top. And they are noisy under load. I mean, comically noisy, to my mind. To me, that goes against the whole ethos of owning a Mac Mini or a Mac, for that matter, you want it to be whisper quiet. Also, you need to drill a lot of holes in the old Mini case to accommodate the air in and air out flow.
That leaves us with the lesser NUC models, as I see it; the i5 model that I was looking at seemed to have more powerful graphics that the Brix rival, though I haven't looked into it for a couple of months, so perhaps that has changed. The cost to performance ratio is poor, though, if absolute performance versus a desktop build matters to people. To me, it does matter, otherwise I am spending a lot of time phaffing around, making custom mounts for a basic home cinema box that I don't feel a great need for.
Perhaps the best save-money compromise is to make an i3 model, as the Celeron models still won't work, as far as I know, there isn't a graphics driver for them and I doubt ever will be, unless you want to turn your G4 Mac Mini into a Linux Elementary box, say, and go for that whole clean OS look that we Mac users like. I am still seriously considering doing this (i3, not Celeron and Linux, though that's plan B) but time is a consideration and it would be helpful if I could find people who already done what we want to do. I don't have a tool shop, so any pieces of metal I buy to make an I/O at the the back, which I guess I would then spray white or polish for many hours to a mirror finish, I am going to be drilling them out and then filing manually; it would be nice to have the measurements for that in advance. Other considerations, do I fit a Blu-ray reader and which are the quietest in operation? It needs to be slot loading. Ages ago, I was looking at a Panasonic blu-ray slot-loading model but it was more money than I wanted to spend.
I am waffling away in the above more in hope than expectation that others have gutted their old PowerPC Minis and upgraded with the internals of the Intel NUC units. If anyone has any build links they would like to share, that would be wonderful. It is a pitiful thing to have an old Mac Mini sitting in a cupboard, gathering dust. It is such a classic design. I would prefer not to drill holes in the case, if possible, to make the mod reversible.
