Homebrew How fast can data be uploaded from FCRAM to VRAM?

[DiscostewSM]

I'm coming back from a long hiatus regarding 3DS stuff, and one thing I want to try and improve on for my tests is rendering speed, so I want to use VRAM to hold my texture data instead of FCRAM, but to do that, I'd need to transfer that texture data over. The problem is that my texture data gets manipulated every frame, and because I can't directly manipulate such data in VRAM, I'd need to upload it in full. I'm only looking to upload about 768KB each time. Maybe more, maybe less (hopefully half as much if my tests work well). If transferring is really quick, then this could help me out a lot. I'm using Citro3D and transferring via C3D_TexUpload. Please let me know if it's possible and if a better approach than the function I'm using is available.