There is always a bit of confusion concerning how much RAM (random access memory) is needed and how much your system can use.  In this short article I’m going to try and detail enough information so you can evaluate your own system’s needs.

 

There is always a bit of confusion concerning how much RAM (random access memory) is needed and how much your system can use.  In this short article I’m going to try and detail enough information so you can evaluate your own system’s needs.

With the price of RAM at all-time lows, increasing your RAM ‘may be’ the least expensive performance gain you can get from your system.  Let’s look at some things we should know:

 

With the price of RAM at all-time lows, increasing your RAM ‘may be’ the least expensive performance gain you can get from your system.  Let’s look at some things we should know:

 

It helps to first know a few things concerning RAM (Random Access Memory):

a.  An SSD is faster than a Hard Drive, RAM is faster than an SSD.  All three can and will be used when processing images or executing other programs.  The key to determining how best to distribute your resources is in understanding when your  operating system and/or program is tasking which resources.

b.  How much RAM you can access is limited in an x32 operating system.  An x32 OS, depending on the BIOS of the machine it's installed on, can use from 3 to 3.2gigs of RAM.  Any amount of RAM over this amount isn’t used.   x64 OS's are limited too, but way beyond what ANY current system can hold.

c.   RAM comes in different speeds, but the default speed for DDR3 RAM used in desktop is currently 1033.  Faster RAM is nice, but you'll need a BIOS which supports RAM profiles or specific RAM settings.  Most support specific RAM settings but this is beyond "easy" for the average person, while RAM profiles are very easy for everyone.

 

c.   RAM comes in different speeds, but the default speed for DDR3 RAM used in desktop is currently 1033.  Faster RAM is nice, but you'll need a BIOS which supports RAM profiles or specific RAM settings.  Most support specific RAM settings but this is beyond "easy" for the average person, while RAM profiles are very easy for everyone.

 

RAM usage in a system is affected by:

The program being used and how it's programming executes instructions.  It's a mistake to think that since you have a 20mb image, it only needs 20mb of RAM to process that image.  If the RAM is available, an imaging program will often use all available RAM to process an image, and still need to write to a 'scratch disk file' of 20-50gb or more.  Without knowing or understanding how image software is programmed we won't know the specifics of how/why, but it's enough to know it does.

How many programs being used.  For instance, the  more tabs in a browser we use, the more RAM the browser uses.  If you run Lightroom, Adobe CS5, Outlook (email), a browser, a torrent client, Windows Media Player, the Operating System, and whatever else you run.. it uses a lot of RAM.  More RAM allows you to run more programs at the same time without slowing the machine.

RAM usage isn't constant.  RAM use is dynamic, as you perform certain tasks with an open program, open close files, open/close programs, your RAM usage will change.

A RAM usage monitor only shows you how much RAM your system is using then with all its current restrictions/options.

Your operating systems has a memory manager.  The history of memory managers is very interesting.  This is a matter of programming and they've evolved and become much smarter over the years.  Memory managers assign RAM to a task on request, and then (ideally) release the RAM when the task is finished.  "Memory holes" are when not all of the RAM is released as it should be.  This is why old XP (and previous versions of Windows) machines needed frequent rebooting to maintain maximum performance.  With Vista is got much better at eliminating memory holes, with Win7 that much better again. 

Win8 will improve memory management even further. A memory manager basically looks at how much memory your system have, how much memory your OS overhead is using, how much memory your programs ‘must’ have, and then distributes available memory trying to keep all programs as well supplied as possible.  You might only be using 2gb now, but if you install 4gb, or 8gb, or more, your memory manager will see this and task your RAM more, and your SSD/HDD less thereby greatly enhancing the performance of your system.

Some programs (CS5 Photoshop for example) allow you to set the amount of system RAM (memory) it uses.  This works in concert with your operating system memory manager and is a very advanced function.  You won't see this option on many programs because of this.

 

As you read this, you can see that many things affect RAM usage, and that the more capability you have, the more the operating system, memory manager, and programs will use.   RAM is faster than an SSD which is faster than a HDD..  Each has different limits and each has different cost factors.  When building a system you need to consider these limits and cost factors to get the best performing system for the least amount of money.

 

As you read this, you can see that many things affect RAM usage, and that the more capability you have, the more the operating system, memory manager, and programs will use.   RAM is faster than an SSD which is faster than a HDD..  Each has different limits and each has different cost factors.  When building a system you need to consider these limits and cost factors to get the best performing system for the least amount of money. 

 

Some additional facts concerning RAM usage:

Every operating system uses a “page file” by default.  A page file is a portion of your hard drive or SSD you set aside for the programs to use when executing their tasks.  This default size is set by the OS depending on how much RAM you have and how much HDD/SSD space is available, but frequently is 20-50gb in size depending on the amount of RAM in your system.  By default Windows assigns a page file 1.5x the size of your RAM.  You can up that manually to 3x. This is simply a section of your HDD/SSD the operating system uses ‘in place’ of RAM when it needs more RAM.. which is almost all the time.  You can stop this page file from being used, or allow it to use more of your HDD/SSD up to the 3xRAM allowed.

Imaging programs like Lightroom, Photoshop CS5 and most others.. also use a “cache file” for their RAM overhead much like the OS uses a page file.  You can often set which drive and alter the default size in the preferences menu.

Imaging programs like Photoshop CS5 also allow you to set a “scratch disk” and alter its drive and size.. this is used for image overhead and not the program overhead, though depending on the programming of the imaging software or plug-in, this line can be very murky.

 

Imaging programs like Photoshop CS5 also allow you to set a “scratch disk” and alter its drive and size.. this is used for image overhead and not the program overhead, though depending on the programming of the imaging software or plug-in, this line can be very murky.

 

This gets complicated trying to understand because your OS’s page file, your imaging programs cache files, and their scratch disks all interact.. lots of good reading on this topic out there.

Now.. considering all of the above.. A system will easily use almost as much RAM as you can afford.  RAM being the fastest of all memory in your computer affects performance in a huge way.  So, the more RAM the better, to an certain point.    It’s also helpful to designate your fastest SSD/HDD for cache file and scratch disks.. the faster they are, the better performance.  When designing a system, it’s all about knowing (having experience) with certain programs (or types of programs), how they use RAM, and then balancing the system RAM, SSD, and HDD types/amounts, percentage of tasking, and cost..

 

How much RAM?  Win7 machines should have a minimum of 4gb.  Vista 2gb but will greatly benefit from 4gb, a very noticeable difference.  For most gaming 6gb of RAM will get you to the “point of marginal returns”, for most image processing 12gb, and light to moderate video rending 24gb, and heavy video rendering 48gb+.   The “point of marginal returns” is an economic term which is basically saying you’ll see significant performance gains as you add more, but there comes a point where adding more reduces the gains to a smaller amount which makes you stop to consider the cost exceeds the value of the gain.

 

Depending on the above paragraph, these ‘general’ guidelines apply to ‘most’ people:

Use a x64 OS for your next system.  x64 drivers and support for modern machines are just as readily available as for x32.  x64 allows the OS to recognize and task more RAM.

Buy the fastest SSD’s and storage drives  you can afford.  You’ll realize their performance benefits across the board on every task you perform.

How much RAM?  Win7 machines should have a minimum of 4gb.  Vista 2gb but will greatly benefit from 4gb, a very noticeable difference.  For most gaming 6gb of RAM will get you to the “point of marginal returns”, for most image processing 12gb, and light to moderate video rending 24gb, and heavy video rendering 48gb+.   The “point of marginal returns” is an economic term which is basically saying you’ll see significant performance gains as you add more, but there comes a point where adding more reduces the gains to a smaller amount which makes you stop to consider the cost exceeds the value of the gain.

Of course, even an imaging system will benefit from 48gb+.. it will just access its page file, cache, and scratch disks less often.  But from a user perspective you’ll see/feel less speed improvements on average after 12gb.