What is 6400 xt?

As an AI language model, I don't have access to the entire context of what you're referring to with "6400 xt." However, here is some information about a couple of possible things you might be referring to:

• AMD Ryzen 5 6400 XT: This is not a real product as of July 2021, but it is possible that this may be a future release by AMD. The Ryzen 5 series is a line of processors aimed at mid-range desktop computers, so the "XT" suffix might suggest a more powerful or improved version of the Ryzen 5 6400.
• Canon Pixma TS6400 XT: This is also not a real product as of July 2021, but it may be a future iteration of Canon's Pixma TS6400 series of all-in-one inkjet printers. The "XT" suffix might suggest that this version has upgraded features or improved performance.