Tuesday, April 26th 2022
Dell's DDR5 CAMM Appears in More Detail, Comes in Several Shapes, Won't be Proprietary
Last week the first details of Dell's CAMM (Compression Attached Memory Module) made an early appearance courtesy of a product leak, but now official details have appeared and the good news is that Dell is saying it won't be a proprietary solution. The Compression Connector looks unlike anything used by consumer computers today and Dell is said to be hoping that it'll be the next industry standard for memory modules, according to PCWorld. The interposer mentioned in the previous news article is also mentioned and allows for a pair of DDR5 SO-DIMMs to be used, albeit with a much taller Z-height.
Dell is apparently planning on getting its CAMM approved by the JEDEC, which is the standards organisation when it comes to memory. However, even if the CAMM format is accepted as a JEDEC standard, Dell holds patents and is likely to charge some kind of royalty fees to interested parties. That said, if it becomes a JEDEC standard, Dell has to follow RAND or Reasonable and Non-Discretionary terms, so the royalty fees would have to be reasonable for JEDEC to agree on making CAMM a standard. The main benefit of Dell's CAMM is that the memory traces end up being shorter and more direct, since the CAMM has a single-sided interface, whereas SO-DIMMs are interfaced on both sides, just like standard DIMMs. This would allow for higher speed memory interfaces, without the need of using something like signal re-drivers or re-timers.Dell is apparently getting ready for DDR6 already and told PCWorld that by the time DDR6 arrives, SO-DIMMs are no longer going to be fit for purpose. Another advantage of the CAMM, is that higher memory speeds can be used in combination with greater densities of RAM, as a single CAMM can host 128 GB of DDR5. The type of connector used is known as DGFF and Dell is already using it in some of its products today, as a bridge connector for GPU boards among other things. Dell claims that the DGFF connector is capable of handling frequencies of up to 20 GHz, or four times the speed of DDR5 memory at 4800 MHz. The physical CAMM will come in different shapes and sizes, but the common part is the compression connector, which is as the name implies, compressed in place with the help of a pair of screws. Additional screws are also used to hold the CAMM securely in place, with the modules shown, using between four to six screws in total.
Dell also claims that the CAMM connector can act as a heatsink and help with heat dissipation, although the company didn't go into any details of exactly how this is meant to work. There will be what Dell calls a bolster plate that sits above the CAMM, most likely to protect it from damage from the screws, but it seems like it could also be extended as part of a heatsink if needed. The bottom bolster is what the top bolster screws into, rather than the compression connector itself. It should be noted that the CAMM doesn't have any kind of pins, so precision installation is going to be key, but judging from the pictures provided there are some kind of guides to make this easier. Each of the 14 interface rows appears to have 44 contacts per, for a total of up to 616 interface contact points. The contact points seem to vary in shape and size depending on their function. A CAMM can be single or double-sided, depending on memory density and Dell has developed CAMM's ranging from 16 to 128 GB. Dell will start shipping computers with CAMMs installed later this quarter.
Dell is apparently planning on getting its CAMM approved by the JEDEC, which is the standards organisation when it comes to memory. However, even if the CAMM format is accepted as a JEDEC standard, Dell holds patents and is likely to charge some kind of royalty fees to interested parties. That said, if it becomes a JEDEC standard, Dell has to follow RAND or Reasonable and Non-Discretionary terms, so the royalty fees would have to be reasonable for JEDEC to agree on making CAMM a standard. The main benefit of Dell's CAMM is that the memory traces end up being shorter and more direct, since the CAMM has a single-sided interface, whereas SO-DIMMs are interfaced on both sides, just like standard DIMMs. This would allow for higher speed memory interfaces, without the need of using something like signal re-drivers or re-timers.Dell is apparently getting ready for DDR6 already and told PCWorld that by the time DDR6 arrives, SO-DIMMs are no longer going to be fit for purpose. Another advantage of the CAMM, is that higher memory speeds can be used in combination with greater densities of RAM, as a single CAMM can host 128 GB of DDR5. The type of connector used is known as DGFF and Dell is already using it in some of its products today, as a bridge connector for GPU boards among other things. Dell claims that the DGFF connector is capable of handling frequencies of up to 20 GHz, or four times the speed of DDR5 memory at 4800 MHz. The physical CAMM will come in different shapes and sizes, but the common part is the compression connector, which is as the name implies, compressed in place with the help of a pair of screws. Additional screws are also used to hold the CAMM securely in place, with the modules shown, using between four to six screws in total.
Dell also claims that the CAMM connector can act as a heatsink and help with heat dissipation, although the company didn't go into any details of exactly how this is meant to work. There will be what Dell calls a bolster plate that sits above the CAMM, most likely to protect it from damage from the screws, but it seems like it could also be extended as part of a heatsink if needed. The bottom bolster is what the top bolster screws into, rather than the compression connector itself. It should be noted that the CAMM doesn't have any kind of pins, so precision installation is going to be key, but judging from the pictures provided there are some kind of guides to make this easier. Each of the 14 interface rows appears to have 44 contacts per, for a total of up to 616 interface contact points. The contact points seem to vary in shape and size depending on their function. A CAMM can be single or double-sided, depending on memory density and Dell has developed CAMM's ranging from 16 to 128 GB. Dell will start shipping computers with CAMMs installed later this quarter.