Canon S90 macro options?

I don’t own or have ever owned any of the camera’s you mention but I do like shooting macro.

From your post it’s not clear what kind of subjects you are photographing and therefore It is more difficult to answer your question.

Most compact camera’s can focus most closely (get small objects to fill the image more) when they are fully zoomed out. (There are a few exceptions I believe the G5X II is one of those camera’s). That’s perfect for coins and some insects. Other subjects like butterflies have the habit of flying away when you get to close so in that case it is better to (fully) zoom in

But let’s assume it’s coins: Both of the cameras you mentioned have a minimum focus distance of 5 cm. But the the Canon does so at 28mm equiv and the Samsung does so at 35mm equiv. So the Samsung is more zoomed and therefore the Samsung is (theoretically) simply better at close focusing.

It might be possible to make the Canon focus closer if you make the aperture smaller (the Higher the f-number the smaller the aperture.) A smaller aperture gives you more depth of field and therefore you can focus more closely. I know this works for an Canon powershot A720is. But you probably also need to focus manually. (Set the focus at it’s minimum distance and then move the camera back and forth till you get a sharp image.)

The other option is to get a macro or close up lens. These lenses allow you focus closer. There are two problems with these lenses. The first one is that they are either optically crap or quit expensive (€60,- Marumi DHG Achromat Macro 200 (+5) filter 52mm). The other problem your Canon doesn’t have a lens treat. There used to be something from a company called Carubba you could attach to your camera to get a lens treat but they don’t sell those any more.

So although the S90 is a really capable camera it’s probably not going to replace your S630 when it comes to macro photography and I have no idea what will at your tight budget.