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zram in Linux kernel should be quite close to what the advertised "Compressed Memory" feature is in Mavericks. AFAIK zram is using LZO compression. According t

by AhtiK 13y ago

zram in Linux kernel should be quite close to what the advertised "Compressed Memory" feature is in Mavericks. AFAIK zram is using LZO compression. According to some tests it is about the same efficiency as WKdm (used in Mavericks) but it has bit slower compression speed [1]. zram is an experimental kernel module since 3.2 and can be installed: [2], [3], [4]. [1] WKdm vs LZO http://terpconnect.umd.edu/~barua/matt-compress-tr.pdf http://terpconnect.umd.edu/~barua/matt-compress-tr.pdf [2] Gentoo zram http://wiki.gentoo.org/wiki/Zram http://wiki.gentoo.org/wiki/Zram [3] Arch zram https://wiki.archlinux.org/index.php/Maximizing_Performance https://wiki.archlinux.org/index.php/Maximizing_Performance [4] Debian&Ubuntu zram http://gionn.net/2012/03/11/zram-on-debian-ubuntu-for-memory-overcommitment/ http://gionn.net/2012/03/11/zram-on-debian-ubuntu-for-memory...

morsch 13y ago
Ok so zram creates a compressed block device in memory. Apparently it's sometimes used to hold a swap space for virtual memory. Compression rates are about 50%, ie you can roughly "double" your memory. I was going to say that this is crazy: why waste RAM to hold swap space, when you could use that RAM to avoid swapping in the first place. I still think it'd be odd to reserve a significant chunk of your memory for it. But I can see how it'd be pretty cool if you can manage it dynamically, ie. only start compressing memory as you run out of it to avoid hitting the disk. Of course the usual rule still applies: if your PC swaps often, get more RAM; or if the RAM is not upgradable, go back in time and buy a machine with more RAM, then smack yourself on the head for not doing so in the first place. :)
- diroussel 13y ago
  > I was going to say that this is crazy: why waste RAM to hold swap space Because you can get faster performance, and more importantly lower energy usage, on the same hardware.
deno 13y ago
Also https://github.com/mystilleef/FedoraZram https://github.com/mystilleef/FedoraZram Note that you need kmod–staging from RPMFusion.

by AhtiK 13y ago

morsch 13y ago

Ok so zram creates a compressed block device in memory. Apparently it's sometimes used to hold a swap space for virtual memory. Compression rates are about 50%, ie you can roughly "double" your memory. I was going to say that this is crazy: why waste RAM to hold swap space, when you could use that RAM to avoid swapping in the first place. I still think it'd be odd to reserve a significant chunk of your memory for it. But I can see how it'd be pretty cool if you can manage it dynamically, ie. only start compressing memory as you run out of it to avoid hitting the disk. Of course the usual rule still applies: if your PC swaps often, get more RAM; or if the RAM is not upgradable, go back in time and buy a machine with more RAM, then smack yourself on the head for not doing so in the first place. :)

diroussel 13y ago
> I was going to say that this is crazy: why waste RAM to hold swap space Because you can get faster performance, and more importantly lower energy usage, on the same hardware.

deno 13y ago

Also https://github.com/mystilleef/FedoraZram https://github.com/mystilleef/FedoraZram Note that you need kmod–staging from RPMFusion.