Certainly the more memory in a laptop PC the better but there are other concerns regarding memory in laptops. Laptops are generally more restricted in the amount of memory that can be installed into a system. Sometimes access to that memory can also be a problem if you plan a future upgrade.
How Much is Enough?
The rule of thumb that I use for all computer systems for determining if it has enough memory is to look at the requirements of the software you intend to run. Check each of the applications and the OS that you intend to run and look at both the minimum and recommended requirements. Typically you want to have more RAM than the highest minimum and ideally at least as much as the highest listed recommended requirement. The following chart provides a general idea of how a system will run with various amounts of memory:
- Minimum: 2GB
- Optimal: 4GB
- Best: 8GB
The ranges provided are a generalization based upon most common computing tasks. It is best to check the requirements of the intended software to make the final decisions. This is not accurate for all computer tasks because some operating systems use more memory than others.
Many laptops also use integrated graphics controllers that use a portion of the general system RAM for the graphics. This can reduce the amount of available system RAM from 64 to 512MB depending upon the graphics controller. If the system is using an integrated graphics controller it is best to have at least the optimal or 4GB of memory as having the minimum will impact performance even more.
Types of Memory
Pretty much every new laptop on the market should use DDR3 memory now. DDR4 has been announced but it won't likely make it to market for some time. In addition to the type of memory installed in the laptop, the speed of the memory can also make a difference in the performance. When comparing laptops, be sure to check both of these pieces of information to determine how they may impact performance.
There are two ways that the memory speeds can be designated. The first is by the memory type and its clock rating, like DDR3 1333. The other method is by listing the type along with the bandwidth. In the case the same DDR3 1333 memory would be listed as PC3-10600 memory. Below is a listing in order of fastest to slowest memory types in both formats:
- DDR3 1600 / PC3-12800
- DDR3 1333 / PC3-10600
- DDR3 1066 / PC3-8500
- DDR2 800 / PC2-6400
- DDR3 800 / PC3-6400
- DDR2 667 / PC2-5300 or PC2-5400
- DDR2 533 / PC2-4200
- DDR2 400 / PC2-3200
Laptops generally have two slots available for memory modules compared to four or more in desktop systems. This means that they are more limited in the amount of memory that have available. With current memory module technologies for DDR3, this restriction generally comes to 16GB of RAM in a laptop based on 8GB modules if the laptop can support them. 8GB is the more typical limit at this time. Some ultraportable systems are even fixed with one size of memory that cannot be changed at all. So what is important to know when you look at a laptop?
First find out what the maximum amount of memory is. This is generally listed by most of the manufacturers. This will let you know what upgrade potential the system has. Next, determine how the memory configuration is when you buy the system. For example, a laptop that has 4GB of memory can be configured as either a single 4GB module or two 2GB modules. The single memory module allows for better upgrade potential because by adding another module you are gaining more memory without sacrificing any current memory. Upgrading the two module situation with a 4GB upgrade would result in the loss of one 2GB module and a memory total of 6GB. The downside is that some systems may actually perform better when configured with two modules in dual-channel mode compared to using a single module.
Most laptops today have a small door on the underside of the system with access to the memory module slots. If it does then it is possible to just purchase a memory upgrade and install it yourself without much trouble. A system without an external door or panel for memory access will require installation by a service technician. This generally will add additional expense to the memory upgrade in the future or possibly even the requirement that the system be sent in to a service center which means the lack of a computer until the upgrade is completed. As laptop sizes have continued to get smaller, there are more systems where memory is completely fixed and can't be upgraded at all because of the limited amount of space.