cross-posted from: https://sh.itjust.works/post/21361730
Hello, I came across zram recently and I’d like to know if I should use it, my laptop only has ~4GB of ram, and for the most part it’ll only stutter when I open multiple programs or a game, so would zram be adequate in my case?
Also, would the compressing and decompressing have a significant impact on my cpu?
Yes.
Yes, and consider using zstd (if it’s not the default on your distribution) and be pretty aggressive with the disk size since it has a high compression ratio. I normally set it to 100% (so zram disk size = physical RAM size), but you can experiment with different values.
It can often improve performance and memory latency and usually only has a minor CPU performance impact as it trades cycles waiting for memory for cycles decompressing memory. It is usually decent even on low power embedded devices.
There are a few edge cases where ZRam is not great. If your data is already compressed or encrypted copying it around in memory is much more expensive. It’s also harder to tell exactly how much data can be loaded into the “free” memory. It’s also a bit slower for serialized memory access in large data sets if the compression ratio is low.