Comment 8 for bug 1123272

Results from my 5 year old laptop (X230, Core i5-3320M with 2.6 GHz), for a 1 GB file:

MD5+SHA1+SHA256: 11s => 90 MB/s => 727 Mbit/s
MD5+SHA1+SHA256+SHA512: 15s => 67 MB/s => 533 Mbit/s

That seems like an acceptable baseline performance. You are not likely to hit GBs worth of packages, so you have like less than 10 seconds of maximum CPU use (likely you'll hit 100-200 MB, so 2-3 seconds of CPU burst). I think 2-3 seconds is completely acceptable.

With nettle which is hardware-accelerated, we achieve:

MD5+SHA1+SHA256: 9s => 111 MB/s => 888 Mbit/s
MD5+SHA1+SHA256+SHA512: 12.8s => 78 MB/s => 625 Mbit/s

(Tests might be skewed a bit in favor of apt, as it avoids duplicate reads - I had to run multiple nettle-hash after each other, rather than after each other per block, the overhead is about 0.2 / 0.4s)

The improvement does not seem huge.

Obviously, if you find faster implementations to contribute to nettle, things might improve further.