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Best use of SSD space for high perfirmance------Should OS, swap, Matlab, data be on SSD or spinning drive for max speed? RRS feed

  • Question

  • Hello,

    First apologies if this is in the wrong place. I could not find a forum for general windows performance questions.

    I have a 250gb SSD, 64 gigs of ram, 12 cores, 4tb hard drive space (2 2tb in raid 0) in a Dell Precision Tower 5810.

    I run independent component analyses in the tool EEGLAB under Matlab on 4gb files of EEG data. A parallelized version of ICA utilizes all of my cores. I am trying to understand how to configure or utilize the SSD and RAM to make these ICAs happen as quickly as possible. Right now they take about 12 hours.

    When Matlab is calculating, I don't understand if there is a lot of disk accessing for the OS, and for Matlab. If there is, maybe I should put them on the SSD, but it seems once I issue the command for the calculation, it will put needed routines from the OS and Matlab in RAM rather quickly and then won't be accessing the disk to service OS or Matlab. It seems at that point it would just access the disk for the data. So I can free up needed SSD space by putting the OS and Matlab on the spinning drives, which would then become the C drive, and put that data on the SSD, so that the calculations frequently accessing the data are fast.

    And should I install the OS on the SSD, or spinning drives?

    Thanks

    Jim Kroger

    Saturday, January 16, 2016 5:07 PM

All replies

  • frist think I would due is open task manager using control alt delete then click on view more detail then open the tab performance

    once you have the performance tab open then go to your MatLab (which I am assuming is a MATH LAB PROGRAM) after opening program alt tab back to performance monitor and just watch what is going on with your cpu and ram and hard drive to see which is peaking out first 

    there are many things you can do as far as tweaking how windows uses ram and cpu and your hard drive I also need to know which windows versions you are using  also before I can tell you what your options are

    SSD are way faster the platters because they are RAM have better access times and read and write rates then the fastest spinning platters on the market

    which would be SCSI drives some spindle at 50,000 rpm servers models only

    ram drives or ssd have no spindle or moving parts making it way faster then ram drives the first problem you have is your OS SHOULD BE ON THE SSD

    and using or disk for storage only

    the registry key hkey\ localmachine\ software \current control set \control \SESSION MANAGER\MEMORY MANAGEMENT\ is where you control how windows propagates ram to the system but I have tried all kinds of scenarios using this key WARNING messing with these keys if you calculate more SYSTEM RAM then you have will result in the BIGGEST BSOD YOU HAVE SEEN IN YOUR LIFE using the registry key entry  DWORD: IoPageLockLimit is your key and keeping that under your system ram amount should give you a boost my laptop has 8 gigabytes ram and I set mine at 7521 which 8 gigs of ram would be 8192 after you do this you can go back into system performance monitor and to the performance tab ram and see that it allocated more ram to the pagefile  with 64 gigs like you say you have just make sure you stay under that limit so you wont BSOD cause its hard fixing this after it is done

    But Spindles will always be slower then actual ram period

    the reg key if you are not used to this would be a dword32 write the IoPageLockLimit <--just like that and then use decimal radio button and fill in your amount of ram PLEASE DO NOT USE MORE THE say 60gigs leaving space you can also fill in Second level data cache to what your MOBO has using for L3 cache

    and you can also overthrow the system managed ram in Administrator\Control Panel\System and Security\System\ Advanced \Settings\Advanced\Virtual Memory\ Change \  untick let windows automatically manage paging file size the on the c drive change that I used 50 gigs of space which will also show in the performance monitor on the ram tab also you have to reboot after making any of these changes

    this should help some but I can tell you from expertise that any program that uses raw calculation's on any computer UNLESS its a super computer example CRAY will be a desktop or laptop to death

    you also may be able to do some surfing to find and website that has links to super computers for math computations and use them

    also you may be able to add old computers you may still have around and network them to where you are using more then your cpu

    also if you still try to use the computer after MATLAB is started this will also slow it down

    and last but not least when in the task manager you can right click the process  or (program) click on details then in that tab set the Affinity And Priority also while it runs

    Monday, February 22, 2016 1:11 AM
  • When Matlab is calculating, I don't understand if there is a lot of disk accessing for the OS, and for Matlab. If there is, maybe I should put them on the SSD, but it seems once I issue the command for the calculation, it will put needed routines from the OS and Matlab in RAM rather quickly and then won't be accessing the disk to service OS or Matlab. It seems at that point it would just access the disk for the data. So I can free up needed SSD space by putting the OS and Matlab on the spinning drives, which would then become the C drive, and put that data on the SSD, so that the calculations frequently accessing the data are fast.


    This sounds reasonable. Maybe re-stating the question a little can help getting better replies.

    For example, you can ask how to use Windows performance tools to confirm your guess that the data access creates much more disk activity than accessing program files. Especially, random access activity. 

    You can also put the data on a  temporary 2nd SSD and see if this helps.

    As for keeping programs and data in the RAM: unlike some other operating systems, Windows does not have an easy way to create "RAM drives". It is believed that caching is smart enough, so we should not be needing a RAM drive. So you can ask how to validate that this is true in your case.

    -- pa



    • Edited by Pavel A Monday, February 22, 2016 11:44 AM
    Monday, February 22, 2016 11:35 AM