Microsoft has released a new public preview of the OneDrive sync client for Windows, making it available in a 64-bit variant. The 64-bit client is recommended for users who deal with large files or a high number of files on OneDrive, since 64-bit apps can use more of the system's memory.
For those unaware, the OneDrive sync client is included with Windows 10 and can be installed on older versions as well, and it lets you sync files from OneDrive down to your local machine easily. It integrates with File Explorer on Windows, so managing OneDrive files and folders should feel the same as using a local folder.
To use the 64-bit variant of OneDrive, you'll need a PC with an x64 (technically, AMD64) processor that's running a 64-bit variant of Windows. It's worth noting that Windows on ARM devices - while they use a 64-bit architecture - don't yet support apps designed for x64 processors, so you'll need to keep using the 32-bit client. Microsoft has been working on x64 emulation for ARM64 devices, and that's currently being tested with Insiders in the Dev channel.
You can download the 64-bit version of the OneDrive sync client here, and it will install over your current version if you already have it installed. You'll need to be running a version that's older than the one you're installing, though.