Can a 4 gigabyte micro SD card be used or higher the higher gigabyte cards up to like 8 gigabytes are cheaper and easier to find I wonder if the ROKU is smart enough to format it to use just what it needs and ignore the rest of the space.
Yes should be fine. Users seem to have reported that 32GB appears to be maximum size so 4-8 will work just fine for you if your device has an SD card slot.
However, if you have the 4800 Ultra as pictured in your signature, you won't have a SD slot. (Discontinued after the 4670). If using another model of Ultra, then yes, should be good with an 8Gb.
Well, I put a micro SD card in mine and it worked for a couple weeks, then the Roku got stuck on the loading screen. After a lot of searching the web, the answer that worked was to remove the card. It works now, but now I am getting the channel loading all the time (suggesting I use an SD card). Is this fixed on newer ones (mine is a version 3)?
I guess you could say it's fixed on the newer ones because none come with a microSD slot anymore.
Sometimes the microSD card gets corrupted and has to be reformatted. You should be able to just reinsert it with the power on and the Home Screen displayed and it will be recognized and reformatted, but sometimes you have to take it to another computer and reformat it and then take it back to the Roku.
So does that mean new ones have enough space for a dozen apps? Right now, my roku 3 can only handle maybe 4 and then it has to reload them every time you switch to one outside those 4.
Generally, the issue with the microSD cards in the Roku devices is that Roku is designed to work with 2 GB cards. If you put a larger one in, it will only work with 2 GB, with the remainder wasted. And, those higher density cards seem to be more susceptible to errors, probably (my guess) because Roku isn't designed to work with them.
Roku used to sell 2 GB cards, but I don't think they do anymore, since none of the devices use them any longer, as @renojim said.
If you can find one, that would be cheaper than buying a new Roku. I will say that the Ultra is faster/more responsive than the Roku 3, but as you know, the Roku 3 is still a very good device. If you can spend around $10 to extend it's usefulness, that would be a good thing.
DBDukes
Roku Community Streaming Expert
Note: I am not a Roku employee.
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