Downgrading nVidia drivers under Ubuntu?

[Radium_Angel]

So a notification popped up there was a newer nVidia driver (ver 450, I was using 440) and it didn't mention it was the "open source" version, as opposed to the closed bonary blob that was 440.

So, I updated, and performance under Proton is decidedly worse.

Under the "Software and Updates" and "Additional Drivers", the 440 binary blob is no longer listed.

How go I get it back?

 (It lists 340, 435, and 390 proprietary options, but no 440)

[For Science!]

3 minutes ago, Radium_Angel said:

So a notification popped up there was a newer nVidia driver (ver 450, I was using 440) and it didn't mention it was the "open source" version, as opposed to the closed bonary blob that was 440.

So, I updated, and performance under Proton is decidedly worse.

Under the "Software and Updates" and "Additional Drivers", the 440 binary blob is no longer listed.

How go I get it back?

 (It lists 340, 435, and 390 proprietary options, but no 440)

You could do a manual install if you know which 440 

https://www.nvidia.com/download/driverResults.aspx/154997/en-us