Cheapest DDR3 1600MHz RAM ranked by price per GB

DDR3-1600 (PC3-12800): the most common DDR3 speed

1600MHz was the speed most DDR3 desktops and laptops ended up running, and it is the speed to buy for nearly any DDR3 machine still in use. The 620 DDR3-1600 kits and modules above are ranked by price per gigabyte, from £0.00/GB to £83.49/GB with a median of £5.69/GB; the cheapest right now is ESUS IT MEMORY RAM UPGRADE 8GB for Apple Mac Mini MacBook Pro iMac DDR… at £0.01. Desktop DIMMs, laptop SO-DIMMs and low-voltage modules are all listed, so filter by form factor first.

The names: DDR3-1600, PC3-12800 and 12800MB/s

The same speed appears under several labels. DDR3-1600 is the data rate; PC3-12800 is the module's peak bandwidth in MB/s (1600 multiplied by 8 bytes). Low-voltage modules are labelled PC3L-12800 and run at 1.35V; they are covered in detail on the DDR3L page. A sticker ending in U is a desktop DIMM, S a laptop SO-DIMM, and E or R an ECC or registered server module, which belongs on the server page and will not work in a consumer board.

Latency: CL11 or CL9

The standard JEDEC timing for DDR3-1600 is CL11 (11-11-11), and almost every plain module and laptop SO-DIMM runs at that. Enthusiast desktop kits such as Corsair Vengeance and Kingston HyperX were often sold as CL9, which needs the XMP profile enabled in the BIOS and usually 1.5V. In practice the difference is small, and on a machine this age the capacity is what you will notice, not the timing.

Which machines take it

• Intel 2nd, 3rd and 4th gen Core (Sandy Bridge, Ivy Bridge, Haswell) on 6, 7, 8 and 9-series boards. Ivy Bridge and Haswell support 1600 officially; Sandy Bridge is officially 1333, but most of its boards run 1600 modules, at 1333 if not.
• AMD FX on AM3+ and the AM3 Phenom II and Athlon II boards, plus FM2 APUs. FX processors support faster DDR3, but 1600 is the common and cheapest buy.
• Laptops from about 2011 to 2015, and the DDR3-era Macs, using 204-pin SO-DIMMs.

Mixing speeds is allowed on DDR3: the board runs every module at the speed of the slowest one, so adding a 1600 stick next to a 1333 stick gives you 1333 across both. Matching the capacity in each channel is what keeps dual channel working.

Ranks and high-density modules

Module listings often state the rank layout. 2Rx8 means two ranks of x8 chips, usually sixteen chips on an 8GB stick, and is the standard layout that works on virtually every DDR3 board. 1Rx8 is typical of 4GB modules. Be careful with cheap 8GB modules sold as "high density" or "for AMD only": they use a chip organisation that many Intel desktop chipsets cannot address, and on those boards they are not detected or the system will not start. If the listing does not state the layout, look for the standard low-density 2Rx8 type, or a module from Crucial, Kingston, Corsair or Samsung that names its rank organisation.

For most DDR3 boards 16GB as 2x8GB or 4x4GB is the ceiling and the sensible target; the 8GB DDR3 page lists single modules for topping up. Since the remaining stock is old or second-hand, check the price history on the product page before you buy.