R4 DS Card, R4i SDHC or R4 3DS - The Right Card For Your console!
More choice = More confusion… or at least that’s the case most of the time. If you’re into homebrew gaming on the DS or 3DS system or want to get into it, then you may be pretty confused with all of these R4 Cars out there. Which one works? Which one do you need to buy if you just have the DS Lite? Good questions, all of them. The fact is that there are so many fake and clone cards out there that finding out what card is right, is like looking through a bargain bin basket in some discount store. Not because these items belong in the bargain bin, but because the fake clone cards do, and they have numerous models of each of those clones.
So how can I help you? I don’t know if I can. It depends on whether you want to buy the real R4 DS Card, the genuine one, or whether you want to simply spend $10.00 on some copy card, that unfortunately, and really, will not work past any single firmware update. The sad truth is, they sell these cards as if they were real authentic cards, but they are not. In the list below, you should get a good idea of which REAL card you need to get, depending on the which system you have right now - or plan to have in the future.
Without further ado… here is the run down on the R4 DS that will work on you system. There are 2 stores that I have dealt with for these cards, and I can only speak for cards I have. http://www.modchipstore.com is one of them, and R43DS.org is another that I have cards from, either directly (my own) or friends / relatives that have bought cards from them.
R4 DS Card for Nintendo DS and the DS Lite

Here you’ll want to look at the original R4, this is the one that was made when just the DS was available, and it worked on the DS Lite too. It’s the old stand by as I call it. Whenever I wanna just take my DS lite with me, I always make sure I have my r4 ds card as well.
R4i SDHC For Nintendo DSI and DSi XL systems

The original R4 DS Card won’t work on the DSi and DSi XL. But the guys behind the card made sure they have it covered with their R4i cards, which were designed and released just for the DSi and DSi XL. With the DS and DS lite, there were cosmetic changes, but nothing changed on the inside, so to speak. The DSi on the other hand was a complete overhaul of the DS console. This was the card that brought SDHC support to the R4 brand, with cards up to 8 or 16GB in size being supported, it was a huge amount of space.
R4 3DS for the Nintendo 3DS system:

If you have a Nintendo 3DS, not only are you lucky… you can also expect all of the same homebrew goodness on your new 3d hand held system. There are 2 choices when it comes to the 3DS console. You can use either the R4 3DS Card, or the R4i Gold card. Both of them will work just fine on your new 3DS, and will let you play all of your DS and DSi homebrew games and media. I have to say here that the both of the cards are backwards compatible with every previous version of Nintendos hand held systems.
I hope this quick breakdown will help you in avoiding the fake cards that will just cause you non stop headaches, and also, help you in making sure you choose the right card for your system.