Memory comes in various speed ratings and sizes per DIMM.  It can be confusing to try to understand which will offer the best performance and layout.  We have undertaken extensive testing in many applications including Photoshop and Lightroom in order to fully understand the implications of using different memory types and configurations in your photography PC.  Here we give you the information you need to know to fully understand the best way to specify your system memory for best value and performance.

 

Rule 1:- Always use memory in pairs.  This will allow the PC to access the memory in dual channel format and will increase the memory bandwidth significantly.  The performance increase is relatively modest at around 5% but its essentially free performance because using 2 sticks of memory instead of one doesn’t usually affect the price.  If your motherboard is a high end board which allows access in quad channel, there is little benefit in populating all 4 memory channels in Photoshop, performance seems to max out at dual channel.  The increase in performance by going from 2 DIMMs to 4 DIMMs in a quad channel system is only 0.5%.  If you have a motherboard with 4 memory channels or just 4 memory slots, you may be better to leave these free for future memory upgrades later as a larger amount of memory may improve performance when handling large image file sizes.

 

Rule 2: The size of each memory DIMM doesn’t affect the performance.  For example, a system configured with 4 x 4GB memory would perform at the same level as a system configured with 2 x 8GB DIMMs.  In this example, you would be advised to specify 2 x 8GB DIMMs even if your motherboard has 4 memory slots because it leaves you two free slots so you can add more memory later.

 

One important caveat for DDR5 systems. The “leave two slots free” advice was written for DDR4, where adding a second matching pair later works well. DDR5 boards behave differently: with all four slots populated the memory controller drops to around 4000MHz to 4400MHz, and a kit of two with two more sticks added later is often unstable even when the parts look identical. On a DDR5 system, buy the capacity you need at the outset as a single two-stick kit, whether that is 2x16GB, 2x32GB or 2x48GB, and leave the other two slots empty.

Rule 3: Memory speed does make a small difference to system performance.  DDR4 runs at 3200MHz in current systems, and DDR5 from 5600MHz upwards.  DDR5 memory speeds start at 4800MHz and increase to over 6000MHz.  There is an increase in performance as you increase memory speed but the performance benefit reduces with each increment.  For a balance of stability. compatibility and performance, we recommend using DDR4-3200 or DDR5-5600 memory for your photography PC.  Beyond this speed, performance benefits are small and there is a chance of impacting long term system stability.

 

The final consideration is how much memory to install in your system.  The answer really depends upon the size of the images you are likely to need to process and the format they are in.  Using RAW image files will offer the best quality but the file sizes will be larger.  As a rule of thumb, later versions of Photoshop will also have a heaver demand on system resources and will likely benefit from increases in system memory.  Updated September 2026. Photoshop’s neural filters, Lightroom’s AI Denoise and the newer generative tools hold far more in memory than the 2023 versions did, so our guidance has moved up a step:

JPEG and light RAW work, 24MP cameras: 16GB minimum, 32GB recommended
RAW editing, 24 to 45MP, Lightroom catalogues: 32GB
Medium format, 60MP+, panoramas and heavy layering: 64GB
Studio and commercial batch work: 96GB or more

Choose the capacity your files need now rather than planning to add to it. On our DDR5 systems that means picking the right two-stick kit in the configurator: 2x16GB, 2x32GB or 2x48GB, all running at full speed. Memory has also been the most volatile component cost of the past year, which is one more reason to get the specification right first time. See our note on component prices for the background.