Compression Attached Memory Module (CAMM) is a memory module form factor which uses a land grid array (LGA). CAMM can refer to both the general form and an early version developed by Dell. CAMM2 is the JEDEC-standardized version defined for DDR5 and LPDDR5.
Before 2022, most laptops either SO-DIMMs or soldered-on memory modules. SO-DIMMs were developed in 1997 as a size-reduced version of the DIMM memory module. Both are removable memory modules that use an edge connector ("slot"), which means that the contacts are all on one side arranged in a row. [1] Faster memory of the DDR5/LPDDR5 generation are very sensitive to the synchrony of signals, a large amount of PCB area, both on the computer motherboard and the memory module itself, need to be dedicated to carefully length-matched traces. The longer these traces get, the more power they waste, and the harder it is to keep the speed high while keeping the signals intact. Soldered-on modules do not have this problem, but they are not user-replaceable. [2]
Dell engineer Tom Schnell developed the original version of CAMM. By replacing the edge connectors with a land grid array, many more pins can be connected at the same time with much smaller variation in trace length (and hence less extra trace length to match them). As a result, shorter traces are needed on the motherboard and the memory module PCBs, allowing the module to run at a lower voltage at higher speeds. [3] [2]
Compared to SO-DIMM, CAMM provides lower thickness, enables faster speeds above 6400 MT/s (hence higher bandwidth), and allows for higher capacities up to 128 GB per module: features previously restricted to soldered-on LPDDR chips.
On the other hand, CAMM sockets takes more area on the motherboard compared to DIMM/SO-DIMM slots. As a result, motherboards do not generally provide spare CAMM sockets like they would provide spare DIMM/SO-DIMM slots. A user who wants to add more RAM to their system will likely need to replace the existing CAMM module instead of simply adding another module.
CAMMs also cannot be replaced without tools as they use screws.
The Dell CAMM was released in 2022. It is rectangular and had 616 contact points (44 per row times 14 rows). It is always rectangular. [4]
CAMM2 was standardized by the JEDEC on December 5, 2023. The standard, dual-channel version has 646 or 666 pins in a long rectangular array. [5] It very closely resembles the kind of "CAMM" demoed by ADATA in June 2023. [6]
The version for LPDDR5 (MO-357E) has a small footprint consisting of a rectangular "body" (23 millimetres (0.91 in) long ×78 millimetres (3.1 in) wide) covering the pins and a trapezoidal "handle" part. It uses the standard dual-channel contacts.
The version for DDR5 (MO-358C) allows for a lot more variation. Chip sizes are defined to house different numbers of memory chips and pin channels: Axxx (40 mm, dual channel pins), Bxxx (54 mm, dual channel pins), Cxxx (68 mm, dual channel pins), Dxxx (28.5 mm, single channel pins), and Exxx (56.5 mm, single channel pins). Each dual-channel socket can be split into two by raising the two halves to different heights, allowing two single-channel modules to be attached. [5] [7]
In April 2022, Dell launched laptops in the Dell Precision 7000-series that used a custom form factor of CAMM for DDR5 SDRAM. [8]
The first computer, and laptop, to use CAMM2 (LPCAMM2: CAMM2 with LPDDR5) memory modules is the Lenovo ThinkPad P1 Gen 7 released in April 2024. [9] [10] [11]
In May 2024, MSI announced the first desktop consumer motherboard with CAMM2 support, the Z790 Project Zero Plus. [12]
At Computex 2025, various companies unveiled CAMM2 products. Chiefly, Gigabyte showed new motherboards, [13] on which various RAM manufacturers demonstrated their new modules: G.Skill demonstrated prototype 5300 MHz (DDR5-10600) kits, [14] Kingston showed 32-128 GB kits from their "Fury Impact" line. [15] TeamGroup also demonstrated 4000 MHz (DDR5-8000) CAMM2 kits. [16]
SO-DIMMs, which were first introduced almost 25 years ago, haven't changed much in all that time besides moving to newer and faster DRAM methods.