What is Memory pressure and Memory Efficiency on Info Panel ?

[Gregory-CJ]

On the Info panel are found memory pressure and memory efficiency... What does this really tell me?

 

Thanks

 

 

 

[v_kyr]

Take a look at:

 

• The Memory load thread here

[Gregory-CJ]

Thanks  v_kyr   !

[Gregory-CJ]

 

 

I consolidated a few comments  from another thread here.

 

 

Hi Frank,

 

Memory Pressure is actually the one you are looking for - once it hits 100%, it means Photo is using the disk..

 

Memory Efficiency is simply a measure of how well Photo is managing to remove redundancy internally (ie. clone a pixel layer - efficiency will increase - until you start editing pieces of the cloned layer, etc. etc.)

 

Hope this helps,

 

Andy.

 

[Gregory-CJ]

Hi  Andy,

Just so that I completely understand, Memory pressure measures  what percentage of Ram  AP is  using and once it hits 100% then AP writes to Disk... right?

But I still don't get what memory efficiency is.... would you mind giving a more detailed description of what ME is and why does the percentage move into the thousands?

 

Thanks

 

Gregory

[R C-R]

Just so that I completely understand, Memory pressure measures  what percentage of Ram  AP is  using and once it hits 100% then AP writes to Disk... right?

 

I believe he means that AP is paging data to disk, which is different from saving a file to the disk. When apps run out of working memory, the OS starts moving chunks of data out of RAM into virtual memory, a section of the disk set aside on the fly as a temporary storage location. If & when that data is needed again by the app it is paged back into RAM.

 

Since it takes time to move data onto & off of the disk, this can cause the app to slow down while it waits for the data to be moved into RAM, sometimes long enough for the spinning wait cursor (sometimes known as the "spinning beach ball of death") to appear.

 

I am clueless about what memory efficiency means, other than I think it might be some kind of measure of data redundancy.

[anon1]

I believe he means that AP is paging data to disk, which is different from saving a file to the disk. When apps run out of working memory, the OS starts moving chunks of data out of RAM into virtual memory, a section of the disk set aside on the fly as a temporary storage location. If & when that data is needed again by the app it is paged back into RAM.

 

Since it takes time to move data onto & off of the disk, this can cause the app to slow down while it waits for the data to be moved into RAM, sometimes long enough for the spinning wait cursor (sometimes known as the "spinning beach ball of death") to appear.

 

I am clueless about what memory efficiency means, other than I think it might be some kind of measure of data redundancy.

to put RAM vs SSD or HDD into perspective 

 

http://www.directionsmag.com/entry/ram-is-100-thousand-times-faster-than-disk-for-database-access/123964

 

if you render a huge panorama for whatever reason and your computers has to write to the hard-drive, even if it is the fastest M.2 SSD with a good connector your CPU can no longer work at 100% load because the data can not be served quickly enough. (happened to me once)

 

an Apple reseller once told a friend of mine that you would not need 8GB RAM because the new SSDs were so fast, which is obviously totally wrong.

 

cheers

[Gregory-CJ]

Thanks RC-R

 

Oh yes, virtual memory,, kind of forgot about that.  Coming from a windows environment  I remember that I could set the virtual memory size, but I guess that is not the case with the Mac. As I understand, the Mac OS automatically scales the  virtual memory size , so  I guess the recommendation is to keep lots of space on  the  start up hard drive, right? 

 

Thanks MBd  

those are hugemungous files for sure.

 

 

As a newbie to AP ( coming from photoshop)  I  can't find anywhere within the UI of AP where the file size of a document is located.

It appears to tell me that the file is 48.00 MP  but no where within AP can I find that the file size is 152.4 MB.. Can you help?  thanks

[v_kyr]

Not sure what you exactly mean here with file size location, but the actual file infos are shown at top left ...

 

• 

... further when you are exporting an image file, the corresponding export panel will show the to be expected file size for saving too.

 

 

Related to memory efficiency I can only guess here, since it's no where explained in detail. BTW it's also used as a term under the listed AP features but here again without any further explanation of what concrete mem efficiency that should be at all. - However, I can imagine that it is some sort of measurement for objects memory allocation/reusage and freeing up, so to say in a similar way memory garbage collection works.

[Gregory-CJ]

Thanks v_kyr,

 

Yes , I did see that file indicator... pixel dimensions, Megalpixel size ( I assume =MP) and color space.

 

Photoshop gives a bit more file info at the bottom of  open doc. To let me know whether or not the file is getting too big for Photoshop to handle.... As I use a lot of layers, which adds to the overall file size and gradually brings Photoshop to a halt.

 

As I am in the habit of monitoring file size in Photoshop to help keep Photoshop running, I am looking for a similar indicator in AP, to alert me that the AP file is getting too big.

 

Example with the same file;

 

On hard drive file size = 1.54 GB

 

In Photoshop file size  = 444.9 MB/ 2.68 GB

 

In AP  = 155.52 MP

 

Assuming MP is tied to the pixel dimensions and not actual file size. (increasing  number of layers= increasing file size).

 

Just looking for a way to monitor file size in AP so that I can eliminate having AP grind to an unexpected halt .

 

Your thoughts.

 

 

[v_kyr]

I see, hmm didn't recognized other file size infos during trying out AP, so can't tell if there are maybe somewhere deep inside some of these infos (like PS shows up) hidden.  But maybe those "Performace options" under the Preferences are of some additional help, there you can setup a RAM usage limit and a Disk usage warning limit.

[R C-R]

Not sure what you exactly mean here with file size location, but the actual file infos are shown at top left ...

That isn't file information, it is the pixel dimensions & total number of pixels (in MP) of the document. Consider that a new document has no file size until it is saved to disk, & even once it has been saved, not all of the file needs to be loaded in to RAM at once. So there is no point in trying to use file size as an indicator of when AP may slow down due to paging to VM. That is (I think) what Info > memory pressure would be useful for.

 

The OS X Activity Monitor.app (in the Applications/Utilities folder) has a memory pressure graph in the Memory tab which shows the aggregate impact on performance of the memory use of all running processes. According the help files for the Apple app, this is determined by the amount of free & cached memory, the VM swap rate, & other factors like "wired" memory that can't be swapped out. Basically, if that graph says in the green zone, memory use will not impact performance. If it creeps into the yellow or red zones then adding more RAM to the system will improve performance; otherwise it will not.

[v_kyr]

That isn't file information, it is the pixel dimensions & total number of pixels (in MP) of the document. Consider that a new document has no file size until it is saved to disk, & even once it has been saved, not all of the file needs to be loaded in to RAM at once. So there is no point in trying to use file size as an indicator of when AP may slow down due to paging to VM. That is (I think) what Info > memory pressure would be useful for.

 

 

Good point for new created documents!

 

Related to the OS X Activity Monitor here ...

• 

... the AP memory pressure value in percentage could be (?) related here to the AP Preferences pre-settings.

 

It's often useful to have to some degree some memory usage control and also some automatic settable warning indicator here, which kicks in when things exceed specific memory sizes. In the past I did a lot of huge Java programming projects and most of the used IDEs sometimes suffered from freeing up themselves their used memory they allocated by the underlayed VM (virtual machine). Since I had myself a big need for some control mechanisms here, I wrote memory control plugin-tools for them, which allowed to control memory allocation/usage and automate forcing garbage collection in order to free up some occupied memory back etc. I also used setable memory size warning indicators for these, so I was forwarned before the IDE performance slowed down and stalled.

• 

Those lower MB values here were just set low in order to make usability screenshots then, otherwise I would had to wait too long for some GC or warning activity! :)

[R C-R]

v_kyr, thank you very much for the link to that Apple help topic article about Activity Monitor! I had never seen it before.  :)

 

It used to be that the built-in help for AM just had some sketchy info about memory use plus a link to the formidable developer doc about memory management, something I have studied considerably but still struggle to understand at more than a superficial level. The help topic article is much easier to understand & seems to cover all the basic info that users need to know.

[Gregory-CJ]

 

 

Related to memory efficiency I can only guess here, since it's no where explained in detail. BTW it's also used as a term under the listed AP features but here again without any further explanation of what concrete mem efficiency that should be at all. - However, I can imagine that it is some sort of measurement for objects memory allocation/reusage and freeing up, so to say in a similar way memory garbage collection works.

 

 

Thanks V_kyr for this explanation of Mem efficiency, although I don't really see the practicality of it for the end user of AP.

[Gregory-CJ]

... the AP memory pressure value in percentage could be (?) related here to the AP Preferences pre-settings.

 

I wrote memory control plugin-tools for them, which allowed to control memory allocation/usage and automate forcing garbage collection in order to free up some occupied memory back etc. I also used setable memory size warning indicators for these, so I was forwarned before the IDE performance slowed down and stalled.

• ememmon.gif

 

 

Nice coding on that plug-in of yours!  and thanks for the link to the Mac activity monitor... I have used that in the past, although it is convenient to have something right in the application to let you know why your application is suddenly doing strange , unpredictable things, especially noticeable  with a large  Photoshop file (3GB+) and odd  paint brush performance.

 

I can get used to using the AP memory pressure as a gauge. Just have to let go of an old photoshop habit of checking file sizes...

 

You also  mentioned  " the AP memory pressure value in percentage could be (?) related here to the AP Preferences pre-settings."  

This is an interesting thought.

 

 

Thanks RC-R for your comments as well.

[Gregory-CJ]

 

  But maybe those "Performace options" under the Preferences are of some additional help, there you can setup a RAM usage limit and a Disk usage warning limit.

 

I wonder if there is an "ideal setting" for both RAM usage limit and Disk usage warning limit.  I know Photoshop , in its preferences, suggest an  Ideal setting.

 

[v_kyr]

...

 

It used to be that the built-in help for AM just had some sketchy info about memory use plus a link to the formidable developer doc about memory management, something I have studied considerably but still struggle to understand at more than a superficial level. The help topic article is much easier to understand & seems to cover all the basic info that users need to know.

 

The dev doc gives some more finer grade technical insights to the way OS X works here, it's something every dev needs who has to deal with those memory aspects. Also some of the Apple dev tools (like the XCode 8 - Memory Graph Debugger etc.) are valuable for the software development cyclus!

[v_kyr]

I wonder if there is an "ideal setting" for both RAM usage limit and Disk usage warning limit.  I know Photoshop , in its preferences, suggest an  Ideal setting.

 

Screen Shot 2017-02-27 at 11.25.59 AM.png

 

Aren't there any value presets setup? - Can't look into that since I used only a trial version which in the meantime expired due to the time usage limit.

 

But I believe that AP will also use here some wisely choosen values as default too, so to say using some common ideal experienced settings which do fulfill most usage scenarios.

[Gregory-CJ]

yes, there was a default settings for both  but with any slider,,,,, well I ramped up both RAM usage limit and a Disk usage warning limit.

[R C-R]

Aren't there any value presets setup? - Can't look into that since I used only a trial version which in the meantime expired due to the time usage limit.

 

But I believe that AP will also use here some wisely choosen values as default too, so to say using some common ideal experienced settings which do fulfill most usage scenarios.

From what I can tell, RAM use limit defaults to all the installed RAM for both AP & AD. Obviously, it will never hit that limit (because the system & other processes must use some of the installed RAM) but I suppose it might be useful to set a lower limit in some usage scenarios, like if someone is running a batch job in AP & wants to make sure other apps they are using still has plenty of RAM. 

 

Disk Use warning for my system defaults to 32GB for both apps. I have no idea if that varies depending on startup disk capacity (I have a 1 TB startup disk) or something else. I do not know if this has any affect on performance.

 

Regardless, both apps seem to be very memory efficient, much less greedy than Adobe products, so I doubt most users will ever have to worry about changing anything from the default values.

[R C-R]

yes, there was a default settings for both  but with any slider,,,,, well I ramped up both RAM usage limit and a Disk usage warning limit.

I can run up the RAM limit to many times more than the total installed RAM, but it won't matter -- there is no way AP (or AD) can use more than the fraction of the actual installed RAM the OS allows it to use.

[Gregory-CJ]

I can run up the RAM limit to many times more than the total installed RAM, but it won't matter -- there is no way AP (or AD) can use more than the fraction of the actual installed RAM the OS allows it to use.

 

That''s good to know , as I felt inclined to reset the sliders back to their default positions,,, which I can only guess at.  

[Gregory-CJ]

Thanks RC-R for the RAM info,, very helpful.

[Gregory-CJ]

 

.......although it is convenient to have something right in the application to let you know why your application is suddenly doing strange , unpredictable things, especially noticeable  within Photoshop  and working  a large file (3GB+) which produces very a odd and unpredictable  paint brush performance.

 

I can get used to using the AP memory pressure as a gauge. Just have to let go of an old photoshop habit of checking file sizes...

 

 

 I guess my final thought is finding out the upper limits of file size that AP ( as an application) can handle before showing signs of strain and unpredictability , as I found with Photoshop's paint brush tool  interacting with large GB files.  Working in AP will tell.