Content of the material
- What is RAM and how does it work?
- The RAM in Your Computer Resembles a Ruler or Stick
- Media Streaming
- Static RAM
- What does RAM do, exactly?
- Okay, So I Know What I Have. Whats the Easiest ‘Next Step’?
- What Is XMP?
- Why is RAM important?
- How much RAM for tablets?
- OK, I got what RAM is! What about ROM?
- How your phone uses its RAM
- RAM is cheap and having more RAM looks great on a spec sheet
What is RAM and how does it work?
Let’s start with the most basic elements of the question. RAM is where data is stored before processing. RAM stands for Random Access Memory, and it consists of dynamic memory chips that can be written and rewritten with data very quickly. Unlike your hard drive, however, the memory used for RAM is also volatile, meaning that it only holds onto that data while the chip is powered, so it’s not designed to hold information long term.
Essentially, RAM is the memory that actually lets you work with the data needed to run programs and open files. Whenever your computer loads a program or opens a file, it opens up that data in RAM. Even your operating system uses RAM when it’s running. If you want to run a program, it pulls the data from long-term storage on your hard drive to short-term storage in RAM, where it can be accessed quickly enough for smooth operation.
This flow of data between the disk and the RAM is controlled by the computer, which manages the writing of data to physical locations on the memory chip, and that it needs a certain amount of free space to function. For each program you run, it will actively use some of the space for in-use memory and allocate some of the available space as standby memory, essentially reserved space for potential operations.
Once you hit the limit of what your RAM can hold, then your computer will compensate with a swap file, putting some of the data onto your storage drive. It will try to use this swap file in the same way it does RAM, constantly reading and writing the data during operation, but the memory in your storage drives simply isn’t designed to move data as rapidly as DRAM. A swap file still lets you get some things done, but will be dramatically slower.
The bottom line is that RAM is essential to the smooth operating of your computer, particularly for things like multitasking and accessing multiple files at one time. While your overall performance will largely be dictated by the capabilities of your processor and graphics hardware, your memory allotment will directly impact how well you can take advantage of that performance. Too little RAM creates a bottleneck that slows everything down, and the basic rule of thumb is that more RAM is always better.
The RAM in Your Computer Resembles a Ruler or Stick
A standard module or stick of desktop memory is a long, thin piece of hardware that resembles a short ruler. The bottom of the memory module has one or more notches to guide for proper installation and is lined with numerous, usually gold-plated, connectors.
Memory is installed in memory module slots located on the motherboard. These slots are easy to find— just look for the small hinges that lock the RAM in place, located on either side of the similarly-sized slot on the motherboard.
Certain sizes of modules may need to be installed in certain slots, so always check with your motherboard manufacturer before purchase or installation! Another option that might help is using a system information tool to see the specific type of modules the motherboard uses.
Memory modules come in various capacities and variations. Modern memory modules can be purchased in 256 MB, 512 MB, 1 GB, 2 GB, 4 GB, 8 GB, and 16+ GB sizes. Some examples of the different types of memory modules include DIMM, RIMM, SIMM, SO-DIMM, and SO-RIMM.
MB and GB are units of measurement for data. Knowing the differences is important when purchasing RAM and other data-centric devices and services.
Streaming music or binging on videos is a slightly different use case than simple web browsing, putting its own stresses on memory. We looked at both audio and video streaming, across several services, to see how much memory was impacted by video, be it cat videos, news clips, or high-definition movies.
Surprisingly, the overall memory demands weren’t that different from regular browsing. Whether listening to multiple audio streams or watching multiple videos, the overall memory use didn’t change much. Single audio or video streams from Spotify or YouTube used less than 3GB of memory (2,747 MB and 2,532 MB, respectively), and you had to bump that up to 4 or more simultaneous streams to get above the 3GB mark. At that point, you’re streaming an unenjoyable cacophony of sight and sound, but you can add more if you want.
Key takeaway: If your primary uses for a system will be streaming media, a basic 4GB should do the trick just fine.
Static RAM uses a completely different technology. In static RAM, a form of flip-flop holds each bit of memory (see How Boolean Logic Works for details on flip-flops). A flip-flop for a memory cell takes four or six transistors along with some wiring, but never has to be refreshed. This makes static RAM significantly faster than dynamic RAM. However, because it has more parts, a static memory cell takes up a lot more space on a chip than a dynamic memory cell. Therefore, you get less memory per chip, and that increases its price.
Static RAM is fast and expensive, and dynamic RAM is less expensive and slower. So static RAM is used to create the CPU’s speed-sensitive cache, while dynamic RAM forms the larger system RAM space.
Memory chips in desktop computers originally used a pin configuration called dual inline package (DIP). This pin configuration could be soldered into holes on the computer’s motherboard or plugged into a socket that was soldered on the motherboard. This method worked fine when computers typically operated on a couple of megabytes or less of RAM, but as the need for memory grew, the number of chips needing space on the motherboard increased.
The solution was to place the memory chips, along with all of the support components, on a separate printed circuit board (PCB) that could then be plugged into a special connector (memory bank) on the motherboard. Most of these chips use a small outline J-lead (SOJ) pin configuration, but quite a few manufacturers use the thin small outline package (TSOP) configuration as well. The key difference between these newer pin types and the original DIP configuration is that SOJ and TSOP chips are surface-mounted to the PCB. In other words, the pins are soldered directly to the surface of the board, not inserted in holes or sockets.
Memory chips are normally only available as part of a card called a module. When you shop for memory, on many of the modules you can see the individual memory chips.
In the next section we’ll look at some other common types of RAM.
What does RAM do, exactly?
RAM is temporary storage that goes away when the power turns off. So what is RAM used for, then? It’s very fast, which makes it ideal for things the computer is actively working on, such as applications that are currently running (for example, the web browser in which you’re reading this article) and the data those applications work on or with (such as this article).
It can help to think about RAM with the analogy of a physical desktop. Your working space — where you scribble on something immediately — is the top of the desk, where you want everything within arm’s reach and you want no delay in finding anything. That’s RAM. In contrast, if you want to keep anything to work on later, you put it into a desk drawer — or store it on a hard disk, either locally or in the cloud.
Ultimately, RAM allows you to access multiple programs at once with speed and efficiency.
RAM is significantly faster than a hard disk — twenty to a hundred times faster, depending on the specific hardware type and task. Because of its speed, RAM is used to process information immediately. When you want to accomplish a specific task, computer operating systems load data from the hard disk into RAM to process it, such as to sort a spreadsheet or to display it on screen. When it’s done actively “doing something,” the computer (sometimes at your instruction) saves it into long term storage.
So, for example, let’s say you want to work with a spreadsheet. When you start Excel, your computer loads the application into RAM. If you load an existing spreadsheet (which is stored on your hard disk), the operating system copies that information into RAM, too. Then you can work with Excel, crunching numbers in your usual fashion. In most circumstances, the computer responds super-fast, because RAM is fast. When you’re done with the spreadsheet, you tell Excel to save it — which means that the data gets copied to the hard disk or other long-term storage. (If you forget to save and the power fails, all that work is gone, because RAM is temporary storage.) And when you close the application, the computer operating system takes it out of RAM and clears the deck so that the space is free for you to work on the next thing.
One extended use of RAM is to help previously-accessed information be available much more quickly. When you first turn on your computer and launch any application, such as PowerPoint or Spotify, it takes a while to load. However, if you close a program and then relaunch it, the software opens almost instantly (unless your PC isn’t optimized for performance). That’s because the app is loaded out of the significantly faster RAM, rather than the hard disk.
In short, RAM is used for any task that requires fast access to computing resources.
One notable example is the operating system’s own process. For example, if you use Windows, its key functions — such as the ability to display images on your screen — are copied into RAM, because the OS needs super-fast access to the devices you use all the time. Not every device driver is loaded into RAM immediately, but many of them are.
Another example is a Windows feature called SuperFetch, which records your usage patterns. Based on your existing behavior, it automatically pre-loads applications and files into RAM when you turn on your PC. This makes working with your computer significantly faster.
When an application needs a lot of RAM, it often gives you a progress bar or other status report. That’s common when you load a game or powerful application. When you launch a game, you may see a “loading” screen while the computer copies information into RAM, such as maps, character models, and objects. That “loading” message is displayed to ensure you know something is happening, when the developers cannot make the process instantaneous!
Okay, So I Know What I Have. Whats the Easiest ‘Next Step’?
The search ends here for some PC upgraders, as some machines simply can’t be upgraded. The above screenshots, for example, come from an old, DDR3-equipped notebook that doesn’t support modules of 8GB each and already has its two slots filled with 4GB memory modules. A key thing for starters: DDR3 is a sign of an older PC, and you can’t simply swap in DDR4 modules in their place. On both laptops and desktops, DDR3 and DDR4 memory are keyed differently from one another and are incompatible. But if you’re not getting this information from the manufacturer, there are other ways to figure it out.
Memory sellers that specialize in end-user sales (notably, Crucial and Kingston) offer online “memory configurators” to help potential customers find an array of compatible memory-module options from their enormous product stacks. Unlike the oft-outdated memory-module “compatibility lists” that system and desktop motherboard manufacturers maintain on a board-by-board level, memory manufacturers’ lists are constantly updated to represent real-time availability. Buyers can simply select the fastest kit of the desired capacity recommended for their system, but with the understanding that these lists typically lean toward the safest parts, rather than, necessarily, the fastest or best-value ones. (Crucial’s is called Crucial System Advisor, while Kingston’s is Kingston Memory Finder.)Tracking RAM upgrade possibilities with Kingston’s Memory Finder
Now, if all you want is a memory-capacity boost, and you’re not concerned about eking out every last droplet of performance or overclocking, your search can end there. Using a memory configurator is a safe bet, and it is often the best idea for upgraders of laptops, whose memory-upgrade options are usually pretty limited, anyway.
If you’re a PC enthusiast, though, and are looking at a high-performance desktop, a memory maker’s configurator may not go deep enough. We like picking our own memory, which is where the next parts come in.
What Is XMP?
Intel’s Extreme Memory Profiles (XMP) are additional configuration sets, accessed via the system BIOS, that allow the motherboard to automatically apply overclocking values to match the needs of nonstandard memory. As an overclocking technology, XMP has some limitations: Some motherboards don’t support XMP at all, and some modules are programmed only with specific XMP values that exceed a given motherboard’s capabilities.Turning on XMP in an Asus BIOS
It may be an Intel technology, but enthusiast-class AMD motherboards are also designed to support XMP. As motherboards are often programmed to slightly alter certain timings to further stabilize AMD’s different memory controllers, motherboard manufacturers have occasionally applied their own names to this setting, such as Asus and its D.O.C.P.
The usual drawback of XMP involves inadequate module programming. Many memory kits have only two automatic configurations—say, DDR4-3600 CAS 18 and DDR4-2133 CAS 15, where the motherboard will retain the CAS 15 setting when you manually select a middle value such as DDR4-3200. The manual configuration fails if the memory required CAS 16 to operate at DDR4-3200.
Different users can argue differently about the best memory product, but from an ease-of-use standpoint, it’s easier to argue, say, for a DDR4-3200 kit that contains a DDR4-2933 secondary XMP along with basic configurations of DDR4-2666, DDR4-2400, and DDR4-2133 than it is to argue against having those fallbacks. Overclocking is never a certainty, and it’s nice to know that the party won’t stop just because some other part of the system (such as the CPU’s memory controller) isn’t cooperating with an XMP setting that’s supposedly supported by the motherboard.
Why is RAM important?
RAM can process data at lightning-fast speeds. Its ability to randomly access data means you can get to any spot in the RAM just as quickly as any other spot. RAM sits on top of the processor, which explains why your processor can do tasks seemingly instantaneously.
RAM is what you use to do basically anything on your computer. Sure, you can browse through the contents of your hard drive and look through folders and files, but opening any of those files means pulling out a copy and placing it onto the RAM. Only there can data be read and written in nanoseconds.
Inserting RAM sticks into their slots on a computer’s motherboard.
For example, when you edit a Microsoft Word file, you might think you’re working deep inside the folders of your hard drive. But, in computing terms, your hard drive is quite far from your workstation.
RAM puts the information you need right in front of your processor. Imagine wanting to read a paragraph from your favorite book — you could ask a friend to read it to you over the phone (like calling on your hard drive), or you could simply grab the book and read it yourself.
If it had to rely solely on its hard drive, your computer would slow to a crawl, while its memory became overloaded trying to find all the information needed to carry out normal work. And don’t bother trying to boot up your computer without RAM — you’ll simply get an error message.
How much RAM for tablets?
Tablets are not expected to deal with heavy-duty software tasks, so their RAM needs tend to be pretty low — similar to a lot of smartphones.
However, as multi-tab browsers and more complex software continue to make the transition, tablet needs are becoming more and more similar to laptop needs. Current spec options typically range from 2GB to 16GB of RAM, with other considerations like battery life and processor speed often being of greater consideration.
With something like the iPad Mini, which touts 3GB of RAM, its design is more focused on its vibrant display and long battery life. Meanwhile, Apple’s latest 12.9-inch iPad Pro has 6GB of RAM to accommodate the 2-in-1 crowd, although the new 2021 models will ship with 8GB or 16GB. Microsoft’s Surface Go 2 has a default 4GB with an option of 8GB because it falls somewhere between a laptop and a tablet — our reviewer was not entirely won over.
Ultimately, this gives us a guideline for choosing tablet RAM:
- 4GB is OK for lightweight users.
- 8GB is a better fit in most tablet cases.
- 16GB if you plan to use a tablet as your primary PC.
Remember, tablets are generally complementary devices that reside between your smartphone and your PC. If you’re leaning more toward a laptop replacement, buy a tablet configuration with the RAM you’d need for any other desktop or laptop.
OK, I got what RAM is! What about ROM?
While sounding similar, RAM is very different from ROM. Read-only Memory is exactly what it says: a form of memory that a computer can read but not write to. That sounds limited, but you’re actually familiar with it in the form of music CDs or DVD-ROMs.
How your phone uses its RAM
RAM in your phone is mostly used as a place for running apps to store their data. In the simplest terms, that means more RAM can let more apps run in the background without slowing your phone down. But like most things, it’s not really that simple. The RAM in your phone is in use before Android is even up and running.
We’re not going to talk about fancy low-level management or things like compcache or swap partitions here, but this is basically how your phone uses the RAM inside of it. If you want to discuss using storage as RAM, you probably already know this stuff anyway.
- The kernel-space: Your Android phone runs on top of the Linux kernel. The kernel is stored in a special type of compressed file extracted directly into RAM during the device power-on sequence. This reserved memory holds the kernel, drivers, and kernel modules that control the hardware and room to cache data in and out of the kernel.
- A RAMdisk for virtual files: Some folders and files in the system tree aren’t “real.” They are pseudo files written at boot and hold things like battery levels and CPU speed data. With Android, the whole /proc directory is one of these pseudo file systems. RAM is reserved, so they have a place to live.
- Network radios: Data about your IMEI and radio settings are stored in NVRAM (Non-Volatile memory that’s not erased when you power off your phone), but get transferred to RAM along with the software needed to support the modem when you first turn on your phone. Space is reserved to keep this all in memory.
- The GPU: The graphics adapter in your phone needs memory to operate. That’s called VRAM, and our phones use integrated GPUs that have no stand-alone VRAM. System RAM is reserved for this.
Once that’s done, and your phone is up and running, what’s left is the available RAM your phone needs to operate and run apps. A portion of this is also reserved for things that need to happen quickly (low-level operating system functions and housekeeping), but it’s reserved a different way. These are software-based settings the people who wrote the OS and built the kernel for your phone set, and it keeps a set minimum amount of RAM free so these low-level functions can be done as needed without having to wait for an app to free any memory.
All this is why the available RAM listing in settings isn’t the same as the total amount of RAM installed inside your phone. The full amount really is inside, but a portion of it (usually about 1GB or so) is reserved. Your apps get to fight over the rest.
Unused RAM is wasted RAM
You might have heard this saying about Android and memory management. It’s a Linux thing, and Android is a Linux kernel-based OS just like Ubuntu. It means that Android was built to stuff the RAM full of apps and their associated data as fast as possible and keep it full, leaving only the minimum free amount we talked about above open for housekeeping duties.
This is different from how Windows works, though it’s very close if you’re using a Mac. Windows keeps RAM open and free for an app that needs it. Linux keeps an app in memory until the memory is needed elsewhere. That’s also decided by those minimum free settings the company that built your phone set. Apps and their processes are given a priority based on what they do, how they do it, and when the last time they were on the screen. When you want to open a new app, the apps with lower priorities get closed, so the new app has the RAM it needs.
As you use your phone, you’ll use many of the same apps more than others. These apps will tend to stay resident in RAM and be running, so they are available instantly. Having that RAM free instead of having the app(s) already resident in the RAM means the app would need to restart the processes that allow you to interact with them, and that’s slower and uses more battery power than keeping them resident in RAM.
It’s a true saying for your Android (or iOS) phone, but not your Windows computer. It’s kind of true for your Chromebook (also a Linux-kernel-based OS ). Each operating system manages things differently and manages the RAM it has available differently, too. When it comes to your Android phone though, you are better off with almost all the RAM filled with application data instead of free. Either way, it’s available.
RAM is cheap and having more RAM looks great on a spec sheet
Companies charge a lot for a model with more RAM, but most of that is because it means they have another model to manufacture and another parts list to maintain. The actual chips that go inside the phone only cost pennies when bought at volume. But being able to say your phone has 12 or even 16GB of RAM when it’s announced can go a long way when it comes to the spec sheet.
It’s impressive, especially to tech enthusiasts and early adopters. I’ll admit, it gets me interested. I like seeing optimized software that can run well on minimal hardware because it’s an art form; writing code can be beautiful. But I’m also intrigued by what having extra RAM can mean when the two have meshed together in the same device. Seeing 12GB or more of RAM in the specs instantly gets me interested, the same way a high-resolution display does.
Companies that build phones know this. They also know that putting more RAM in a phone means they can get away with less software optimization (a costly and time-intensive thing) or try and do more with their version of Android. Either way, some of us will be buying only because of the specs. That makes the added costs worth it because people talking about your product is priceless.
So how much RAM do you really need? As much as you really need is the right answer. The best answer is as much as you can get.