RAM versus SWAP

[aobreyss]

Bonjour,

I've been trying to find a definite answer to my question, how big should my swap partition be. I have 4GB of RAM on a very fast system. I never user hibernation. I've read about adjusting swapiness, SWAP should be RAM x 1.5 ou x 2 RAM ( which would seem to be overkill), no swap at all. I will mostly run Gnome on an Ubuntu 8.10 installation. Please advise and explain.

Regards, Joyeux Noël

[mikewhatever]

There is no definite answer, like it or not. I'd say you need no swap at all.

[oilchangeguy]

read this:
https://help.ubuntu.com/community/SwapFaq

and +1 on your computer needing no swap.

[Pumalite]

Unless is a laptop and you want hibernation. In that case: /swap= 1.4 of your RAM

[hyperdude111]

You will only NEED swap if you max out your ram. Because you have a large 4GB unless you run a huge number of power apps at once you onl need about 1GB of Ram (just as a precaution).

[mikewhatever]

You will only NEED swap if you max out your ram. Because you have a large 4GB unless you run a huge number of power apps at once you onl need about 1GB of Ram (just as a precaution).

Is there a list of power apps? If not, what are they?

[Pumalite]

I'd like to know too...

[ibutho]

Even with a lot of RAM, it wouldn't hurt to have a bit of swap space. You don't necessarily need to have 2x ram because it would be a waste of disk space. 1GB should be more than enough.

[zephyrcat]

I have a Dell XPS M1530 with 4GB of RAM. I just left whatever it came with, so I ended up with 3.4 GB of swap. System Monitor tells me none of that is being used right now, so I would say you are probably OK with none, but it would not hurt to put in a couple of GBs.

[mikewhatever]

Can you also check what amount of RAM is in use. I think the rule of Swap=1.5xRAM applied well in the days when RAM was pricey and most computers only had up to 512 MB.

[hyperdude111]

Apps like songbird use 100mb+ ram, running ms office 2007 and itunes in wine also use large amounts.

Virtualbox uses huge amounts as you have to set aside some ram from the host to give to the guest. If the guest is vista you end up losing 512mb of ram.

[Pumalite]

Laptops and hibernation are a different matter. Google it.
http://www.google.com/search?hl=en&q=ubuntu+ram+and+hibernation+in+laptops&btnG=Google+Search&aq=f&oq=

[redsoxreed]

I always make my swap double the size of my RAM if there is less than 2 gigs in the machine.

[mikewhatever]

I always make my swap double the size of my RAM if there is less than 2 gigs in the machine.

So if there is 1.5 GB of RAM you'll have a 3 GB swap.How much of it do you think gets used?

[SuperSonic4]

You really don't need it. Just make it 512mb to keep the installer happy if necessary. I've been using k3b, k9copy, firefox, kmess, amarok and dolphin at once and not used any swap

[upchucky]

i have 2 gig ram, 1 gig swap, according to my logs nothing has ever been swapped to the swap, however I may not be using any mem hungry apps.

you have 4 gig ram, "tons" unless you are a server. on a stand alone pc with 4 gig you only need 1 gig swap, and im willing to bet it will never get used.

[Sef]

I think the rule of Swap=1.5xRAM applied well in the days when RAM was pricey and most computers only had up to 512 MB.

That is correct. Unless you do some extremely graphicly intensive applications (movie ediing, gaming, etc.), 1 gb swap will be more than enough. If they are extremely graphically intensive, then I would consider 2 gb swap.