Does vostro 3470 PCIe x16 slot support 2 or1 tb NVMe SSD

On some systems, the PCIe x16 slot is wired for graphics card only.  Since the PCIe x16 slot is not officially supported for storage, there is no specifications for NVMe SSD capacity.  You will have to test and validate through trial and error.

Thanks for replying. On one of the forum, I have seen that NVMe SSD with adaptor can be used.

But capacity of the SSD was not specified in the forum. I am attaching the link for your reference.

https://www.dell.com/community/en/conversations/vostro-desktops/vostro-3470-nvme-m2/647f7d6af4ccf8a8debdaa7e?commentId=647f7d6bf4ccf8a8debdb436

Based on the users confirmations on that thread, you should be able to use NVMe SSD with PCIe x16 slot in your system.  As for the capacity specifications, the same reasoning will apply.  You can install with any capacity as desire and that will be a working with user validation versus specifications.