Tweak Talk

Linux is renowned as a high-performance operating system, and it runs on nearly all of the world's most powerful supercomputers. It also runs very well on regular desktops and workstations, but sometimes people ask for more. Whether you're faced with a low-end hardware setup or a loaded production system with high I/O, there is always room for tweaks and optimizations. Linux is an ideal OS for tinkering, and you have many options for eliminating performance bottlenecks, fixing non-optimal settings, and making the system more fluid and responsive. The goal of this article is to point you to some best practices for tweaking a typical home or office Linux-powered machine, while avoiding some of the outdated or less efficient advice.

The Curse of Low Memory

"Buy more RAM" – that's a frequent response to "I've got only 2GBs." However, sometimes it is not possible to install more memory bars into a computer. An average Linux desktop runs butter-smooth with 8GB, very nicely with 4GB (with some limitations to multitasking), and quite poorly with 2GB or less. Some palliative techniques that bring relief include using zram and zswap. These are the two methods of compressing memory to take down (or even completely avoid) swapping memory pages to the hard drive. Thanks to compression, the system has more free RAM, and with the lower swapping, the filesystem also speeds up. The trade-off is a higher CPU load due to constant compressing and decompressing, but its impact is usually smaller than the lagging caused by a running out RAM.

Zram is a compressed RAM-based swap device designed for systems with no physical swap partitions. It is a Linux kernel module (included since kernel 3.14) that creates a very fast virtual block device backed by RAM and sets it as a top-priority swap "partition." All you need to do is install the supplementary package for the zram systemd service and enable it. In Ubuntu, use the following commands:

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