Make Ubuntu use a minimum of RAM

[nonedrinkwater]

Hi,

I've done a few tests about running Adobe AfterEffects / Premiere CS6 in a Windows 7 virtual machine, in Ubuntu. Along with 3DS Max, these are the only software I have problems with (They force me to reboot into Windows..); I've managed to make all the others Adobe products work under Wine, but these are 64-bit and perhaps too complex for Wine (For now). Running them into a virtual machine would also use way too much memory to be usable.

But I've been wondering about this problem; I have a machine with 8GB of RAM. Assuming I want to avoid rebooting into my real Windows 7 OS, how much can I limit the RAM of Ubuntu, so that I'll be able to allow more RAM to the Windows 7 VM ?
I'm running Ubuntu 12.04 LTS x64 with Unity (Yes, it use a lot of memory. I want to keep it.). I've tried stopping a few processes, and replacing for a session Compiz by Metacity with this:

metacity --display:=0 --replace

It work. Compiz use 80MB of RAM, while Metacity, only 5MB. By stopping a few processes, I've managed to lower the memory used by Ubuntu alone to 11% of 8GB (Well, 7,7). Just wondering, is it safe to disable "Unity-Panel" process ?
By replacing Compiz by Metacity, I don't have the Unity dash, but I can create an empty folder of the desktop, and launch Linux applications by going to /usr/share/applications, that's ok.

I've also optimized my Windows 7 VM, and use an excellent software that I've had a great experience with, GameBooster, used to stop system process during gaming/intense activity.

How can I free more RAM in Ubuntu, so that I can allow more to Windows 7 ? I've now allowed 4,5GB to the VM, but I was at 73% used, I could put some more. 4,5GB is very low to use AfterEffect, even at low display quality.

Would Lubuntu x64 be more efficient? That's not a so awesome solution, because installing another OS takes up space, and I have a (small) 320GB hard drive, with already 3 OS installed (Ubuntu, Windows 7, and Windows 2000, a small partition, for testing). How much RAM would I benefit by running Lubuntu? Maybe running it off a ISO file (Booted from GRUB) do it? Is it slower (Not from a USB stick. Adding an entry to the ISO from GRUB menu) ? Of course, I should be able to auto-install VirtualBox in the ISO file, not sure how.. :S

Any availible option? Can I stop more processes to make Ubuntu more "transparent" ?

Thanks!

i installed ubuntu on a netbook because i use ubuntu on all my other machines, but ubuntu was too slow on an atom processor, after trying several other ubuntu derivations, i installed debian using the 200mb network install, and it runs really fast, i have a dual core atom with a gig of ram and it runs extremely well; im considering installing debian and removing ubuntu on all my other machines.

[GameX2]

Maybe a bit unrelated to your specific case - If you're referring to the max RAM size as per the laptop's official manual, then chances are that your laptop might actually support more RAM than what's written on the book (assuming mb has the latest BIOS). The probable reason is that the vendors make the hardware/BIOS to support the largest possible RAM capacity, but test ( and advertise ) only the largest commercially available dimm size at that point in time.
In my case the laptop's manual says it supports up to 4 GB of RAM, but using 'dmidecode' command I see that it can go up to 8 GB. And my PC officially supports 4GB, but it can go up to 16 GB of RAM, ( currently being used with 6 GB with no issues, see below ). Note the bold lines in red.

$ sudo dmidecode -t memory
# dmidecode 2.11
SMBIOS 2.2 present.

Handle 0x0007, DMI type 5, 24 bytes
Memory Controller Information
    Error Detecting Method: 64-bit ECC
    Error Correcting Capabilities:
        None
    Supported Interleave: One-way Interleave
    Current Interleave: One-way Interleave
    Maximum Memory Module Size: 4096 MB
    Maximum Total Memory Size: 16384 MB
...
Physical Memory Array
    Location: System Board Or Motherboard
    Use: System Memory
    Error Correction Type: None
    Maximum Capacity: 16 GB
    Error Information Handle: Not Provided
    Number Of Devices: 4
...


$ free -m
             total       used       free     shared    buffers     cached
Mem:          5971       5843        128          0        210       4457
-/+ buffers/cache:       1174       4796
Swap:         4093          0       4093

Just my 2 cents.

That's really interesting;
I would love to try, but "dmidecode" list the max RAM as 8GB. :/ (Which is the info I found everywhere)

Is it risky to put more RAM in? Will it simply just won't be detected, if the maximum is reached?
Thanks!

EDIT: Hey! Check the fourth post of the Lenovo forums (My laptop is a Lenovo Thinkpad E420)! :O
http://forums.lenovo.com/t5/ThinkPad...TO/td-p/892413

COOL.

[erind]

That's really interesting;
I would love to try, but "dmidecode" list the max RAM as 8GB. :/ (Which is the info I found everywhere)

Hmm ... not sure what to say but it's definitely worth a try.

Is it risky to put more RAM in? Will it simply just won't be detected, if the maximum is reached?
Thanks!

Not really, the worst it could be (I think) the laptop won't boot, or BIOS won't see full 16 GB, ... but nothing serious really.

EDIT: Hey! Check the fourth post of the Lenovo forums (My laptop is a Lenovo Thinkpad E420)! :O
http://forums.lenovo.com/t5/ThinkPad...TO/td-p/892413

COOL.

That's really something to consider, the guy in that thread is sure that it can go up to 16 GB.
It doesn't hurt to try ... keep all the receipts, just in case

[GameX2]

I want to try so bad, but it's quite expensive (for me). :S

Will a see a different in the general speed of Ubuntu (I know, 16GB is a lot) ? Or will that be a benefit purely for video editing, virtualisation, 3D modeling and gaming (I've got only 2 games which are going to appreciate the boost much. Harry Potter 7 Part 1 and 2.) ?

Which brand is good (I use DDR3) ?

Thank you very much for the info !

EDIT: I've read I won't get benefit from gaming by upgrading RAM - not an issue, since the only demanding games I run are the 2 last Harry Potter, and really playable, just not always 100% fluid.

I do a lot of PhotoShop, as well a video editing (Premiere/AfterEffects), and 3D modeling. Soon, I'll start to animate 3D model, as well. I guess that's still interesting. But.. expensive.

[erind]

I want to try so bad, but it's quite expensive (for me). :S

Check the daily deals' sites, say dealnews.com ... There's always a good chance to find them on sale one day or another.

Will a see a different in the general speed of Ubuntu (I know, 16GB is a lot) ? Or will that be a benefit purely for video editing, virtualisation, 3D modeling and gaming (I've got only 2 games which are going to appreciate the boost much. Harry Potter 7 Part 1 and 2.) ?

Yes, there'll surely be an overall improvement, however it's not only the RAM, it's the CPU, the slower performance of the hard disk is a big bottleneck - a SSD will definitely help a lot, but it costs though.
As others have stated, the best performance comes from a low footprint OS (Lubuntu or Xubuntu), an optimized VM, (use Win XP as VM if that is an option), but still it wouldn't be the same experience as you'd get from running the software natively by dual-booting.

Which brand is good (I use DDR3) ?

Any brand will do, but read the reviews first. Stay within the specs of your machine (DDR3).

I do a lot of PhotoShop, as well a video editing (Premiere/AfterEffects), and 3D modeling. Soon, I'll start to animate 3D model, as well. I guess that's still interesting. But.. expensive.

Check those deals' sites, ... you might get lucky someday.

Thank you very much for the info !

You're welcome

[jeldridge13]

Hey erind,

Random question, with trying the "dmidecode" command, I get this: /dev/mem: permission denied

I am really new to this whole Ubuntu thing, however, just curious if it is possible to enable those permissions?

[erind]

Try it with sudo, cause it needs elevated permissions to display the results. In a terminal type:

sudo dmidecode -t memory

Or with longer output:

sudo dmidecode

PS. Files in /dev directory are special device files, and their permissions can't ( and are not supposed ) to be changed. In this case /dev/mem is a special file which dmidecode reads from.

http://en.wikipedia.org/wiki/Device_file