RSS reader that copes well with over 1million articles

[electrolux]

I currently use Akregator as my desktop RSS reader, and whilst it isn't the current one (and so this might have changed) it does not cope well with a large number of articles. I am tempted to blame its backend databases, but truly I'm not too sure.

I have a LOT of items in the 146 feeds in Akregator. There are 1.33million unread articles, no idea how many marked read (likely 100-200% again), and many operations in the program are now a chore. Clicking into the TV folder of feeds and the GUI freezes for 3+ minutes for example, and the search has become is a joke. The realtime search means even typing a search is effectively broken. Akregator appears to be single threaded too, only ever using 25% of my quadcore (meaning things could be 4x less bad?), but oh, it loves RAM. 1.9gig currently.

I know that if I didn't choose to maintain such ludicrous archives things might not be so bad (some feeds I do have it delete old articles), but I find new feeds to add quite often and sooner or later Akregator's shortcomings would arise.

What GUI feed readers do people recommend? Ideally one that handles well hundreds of feeds, where some feeds have >100k items. Akregator's archive files are .mk4 files, the file command identifies them as "data", not too helpfully. . . Looking into it they seem to be Akregator-specifc, but knowing Linux they are likely some pre-existing database format. Would a serious database backend solve my problems?

Thanks