What exactly does enable-lightweight do?

[moonman]

Hello everybody,

I am wondering what exactly enable lightweight does. Would I benefit from using it on a Pogoplug with armv5 1.2GHz CPU and 256 RAM with plugapps(archlinux for arm, no uclibc here). Would it make downloads/uploads faster or slower, increase/decrease disk I/O (ext4)? That device isn't really a slow mips(el) router with 32mb of ram, but it also isn't a core 2 duo with >1GB ram, so I am kind of confused.

[lazybones]

I was wondering the same, I run transmission on a nas with very little ram... I did not see any update on what this exactly does in the wiki or release notes.

[moonman]

Well, it looks like it reduces cache size from 4 to 2, does something to encription (I don't really understand what though, at least from the trac changeset), and disables disk prefetch. I can see it being useful, but not for the 1.2 GHz arm with 256 ram.
Thanks

[Jordan]

Encryption is one of the more CPU-intensive parts of bittorrent, so in enable-lightweight, the default preference is for unencrypted connections. This is just a changed default -- it can still be overridden by the user and/or by peers that insist on encryption.