lip5016

Q: Can some1 please SCHOOL ME on what a "RAM Disk" is? should I be using one?

Can somebody please tell me what a "RAM Disk" is, and if I should be using one?

 

I was looking on the internet about how Apple used to have this "RAM Disk" thing in their old Mac's before eventually doing away with this feature.. I'm no expert on the subject, but it sounds like you can use a chunk of your harddrive space as RAM?

 

This sounds pretty sweet, but I was also reading that the information created when you make one of these things can easily be lost.. I'm a performance junkie, so I always love the allure of improving my machines, but not at the expense of losing important information..

 

1. Can somebody please tell me what this whole "RAM Disk" concept is about?

 

2. Should I be using a "RAM Disk" when I do work in Logic X or w/music in general?

 

3. What are the benefits of a "RAM Disk"? (Any negatives?)

 

4. How much do they really improve performance?

 

5. How big should you set your RAM Disk size? (to avoid memory paging) I've read that you should use no more than 50% of your total RAM as your maximum sized RAM Drive.. Thoughts?

 

6. How do you even use a RAM Disk? Do you just make it and let it sit there while it does the rest? What do you do when you want to close it or turn off your computer or something to avoid data loss?

 

CAN SOMEONE PLEASE DROP SOME KNOWLEDGE ON ME? THANK YOU!

 

 

 

oh yeah, also, i got this app thing too.. not sure what size to try out? should i bother messing with a RAM Disk at all? i have 16gb installed internally as hardware

 

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Thank you!!

MacBook Pro, OS X Mavericks (10.9.5)

Posted on Oct 21, 2014 6:52 PM

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Q: Can some1 please SCHOOL ME on what a "RAM Disk" is? should I be using one?

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  • by BobHarris,

    BobHarris BobHarris Oct 21, 2014 8:11 PM in response to lip5016
    Level 6 (19,609 points)
    Mac OS X
    Oct 21, 2014 8:11 PM in response to lip5016
    1. Can somebody please tell me what this whole "RAM Disk" concept is about?

     

    Some of your RAM is taken locked down and the RAM disk software pretends it is a disk.

     

    All the RAM dedicated to the RAM disk is no longer available for applications.

     

    One area where a RAM disk is still used, is when an operating system is booting from a read only device (such as a DVD), but it needs to be able to pretend it has a writable file system.

     

    I'm no expert on the subject, but it sounds like you can use a chunk of your harddrive space as RAM?

    What you are describing is NOT RAM disk, but is called virtual memory.  Mac OS X has been using virtual memory since its first release.

     

    There may be some very rare situations where a RAM disk might help an app that only a 32-bit app and uses disk because it does not have enough disk space for scratch area.  So if that scratch area was a RAM disk, it would get fast disk performance, as it was not really talking to a disk, but rather to RAM. Today, apps can be compiled as 64-bit apps which allows it to use much more RAM and not need to use disk.

     

    Also today, it is just as easy to use a  Solid State Disk (SSD) which would give fast disk access (not as fast as RAM, but way better than a rotating hard disk).

     

    2. Should I be using a "RAM Disk" when I do work in Logic X or w/music in general?

    I would assume Logic X is a 64-bit app and can directly use all the RAM it needs.  If it does need to access disk, it would be better to give it an SSD to access, and not a RAM disk, which would take away RAM Logic X could be using.

     

    3. What are the benefits of a "RAM Disk"? (Any negatives?)

    (plus) Fast access.  (neg) Less RAM for applications to use.  Difficult to guess exactly how much RAM to give to the RAM disk.  Getting the application to actually use the RAM disk (apps often have their own ideas on where they should read/write scratch data).

     

    I'm going to stop here, as I do not think it is a good use of RAM.  The operating system tries very hard to use your RAM to the maximum extent possible to avoid expensive disk access (where expensive can be access time as well as battery power powering the disk).

     

    If you really are worried about disk performance, then start looking at getting an SSD.  It will give you much better performance per dollar spent than more expensive RAM.  You can get a terabyte SSD for under $500, were as you Mac can most likely not exceed 32GB (maybe only 16GB) and that RAM is better spent giving it to applications, not a pseudo disk.