Find the answer to your Linux question:
Results 1 to 10 of 10
Can someone help me understand this? The way I read this top shows I am using over 6.5gb of memory but System Monitor shows less than 1gb. I must not ...
Enjoy an ad free experience by logging in. Not a member yet? Register.
  1. #1
    Just Joined! bonesTdog's Avatar
    Join Date
    Jan 2011
    Location
    Atlanta, GA
    Posts
    91

    Memory Usage - top vs System Monitor (Solved)


    Can someone help me understand this? The way I read this top shows I am using over 6.5gb of memory but System Monitor shows less than 1gb. I must not understand how to read these correctly. Can anyone help? The attached link shows a snapshot of top and System Monitor.
    http://dl.dropbox.com/u/6865564/Screenshot.png

  2. #2
    Linux Guru Cabhan's Avatar
    Join Date
    Jan 2005
    Location
    Seattle, WA, USA
    Posts
    3,252
    I suspect it's because top and System Monitor handle this case differently:

    Help! Linux ate my RAM!

  3. #3
    Just Joined! bonesTdog's Avatar
    Join Date
    Jan 2011
    Location
    Atlanta, GA
    Posts
    91
    Perfect. Thanks. I figured there had to be a logical explanation.

  4. #4
    Linux Guru Rubberman's Avatar
    Join Date
    Apr 2009
    Location
    I can be found either 40 miles west of Chicago, in Chicago, or in a galaxy far, far away.
    Posts
    11,575
    Yes, this confuses a lot of new Linux users. "I'm not doing anything, and 99% of my memory is used!"... Caching really speeds up the system, but it utilizes a LRU (Least Recently Used) algorithm to keep stuff (files, executable images, etc) in memory because that is the stuff that is most likely to be used again, eliminating the need to read it from disc, which is orders of magnitude (1 order = 10x) slower than RAM, especially in current systems. You can see it if you do something like executing the command "ls -R" on a directory tree. The first time, it is noticeably slow and you will see the disc activity light flash as it reads the file system from disc. Do it again, and the results will be instantaneous and the disc light will stay off because all that directory information is now cached in RAM.
    Sometimes, real fast is almost as good as real time.
    Just remember, Semper Gumbi - always be flexible!

  5. #5
    Just Joined! bonesTdog's Avatar
    Join Date
    Jan 2011
    Location
    Atlanta, GA
    Posts
    91
    Great test to run ls -R. You can really notice the difference. Thanks for the education. Sad thing is I don't really consider myself a new linux user! Just took me a couple of years to ask the question to figure out what I was looking at!

  6. #6
    Linux Guru Rubberman's Avatar
    Join Date
    Apr 2009
    Location
    I can be found either 40 miles west of Chicago, in Chicago, or in a galaxy far, far away.
    Posts
    11,575
    The first step to wisdom is knowing what you don't know! Glad to help "illuminate" things a bit for you!
    Sometimes, real fast is almost as good as real time.
    Just remember, Semper Gumbi - always be flexible!

  7. #7
    Just Joined! bonesTdog's Avatar
    Join Date
    Jan 2011
    Location
    Atlanta, GA
    Posts
    91
    The other thing I know I don't know is how the heck to mark this thread as solved...

    Feeling pretty stupid...

  8. #8
    Linux Guru Rubberman's Avatar
    Join Date
    Apr 2009
    Location
    I can be found either 40 miles west of Chicago, in Chicago, or in a galaxy far, far away.
    Posts
    11,575
    Quote Originally Posted by bonesTdog View Post
    The other thing I know I don't know is how the heck to mark this thread as solved...

    Feeling pretty stupid...
    I think one of the moderators needs to do that now - an inadvertent side-effect of recent changes to the forums...
    Sometimes, real fast is almost as good as real time.
    Just remember, Semper Gumbi - always be flexible!

  9. #9
    Just Joined! bonesTdog's Avatar
    Join Date
    Jan 2011
    Location
    Atlanta, GA
    Posts
    91
    Ok, thanks. Feeling slightly smarter now.

  10. #10
    Administrator MikeTbob's Avatar
    Join Date
    Apr 2006
    Location
    Texas
    Posts
    7,864
    Glad you got everything sorted to your liking. I've marked this thread as solved and closed.
    I do not respond to private messages asking for Linux help, Please keep it on the forums only.
    All new users please read this.** Forum FAQS. ** Adopt an unanswered post.

    I'd rather be lost at the lake than found at home.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •