PC memory module with 128 GB for dual-slot mainboards
Adata announces unbuffered DDR5 memory modules with 128 gigabytes capacity, which are however only suitable for certain desktop PC mainboards.
DDR5 memory module from Adata
(Image: Christof Windeck/heise medien)
Taiwanese memory module manufacturer Adata announces a special DIMM with 128 GB capacity: however, it will likely only work on mainboards that can control Clock-Unbuffered-(CU-)DIMMs and have two slots for it. This consequently allows for a maximum of 256 GB of RAM.
Desktop PCs and notebooks are usually designed only for so-called unbuffered memory modules, or UDIMMs for short. These can currently be equipped with a maximum of 64 GB of DDR5 RAM.
On mainboards with four slots for CUDIMMs, four of the new modules, each with 128 GB, are unlikely to be controllable together because Adata utilizes a special feature: the 128 GB DDR5 CUDIMMs have four ranks instead of just two.
Rank customer
So far, DRAM chip manufacturers produce individual DDR5 SDRAM chips with a maximum capacity of 32 gigabits (Gbit). Eight of these therefore hold 32 GB (8 bits = 1 byte) and together form a so-called rank. A single-rank (SR) UDIMM thus stores 32 GB, a dual-rank (DR) UDIMM stores 64 GB.
More than two ranks are not intended for UDIMMs, but only for Registered DIMMs (RDIMMs), also called buffered DIMMs.
The memory controllers of most desktop PC processors control two RAM channels, each of which can be equipped with a maximum of two DR UDIMMs, meaning a total of four ranks.
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Rank trick
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On a mainboard with two DIMM slots, i.e., only one DIMM per channel (1DPC), a maximum of two ranks are fundamentally intended. However, the CPU's memory controller could still control two additional ranks.
Adata therefore equips the new 128 GB modules with four ranks (4R), soldering twice as many DDR5 SDRAM chips onto them. Adata simultaneously uses a clock driver chip that stabilizes the clock frequency signals. These are therefore 4R CUDIMMs.
According to the press release from Adata, prototypes of the 128 GB 4R CUDIMMs are already running on an MSI mainboard with a Z890 chipset for an Intel Core Ultra 200 processor.
Adata has not yet announced prices or delivery dates. However, due to the currently significantly increasing DDR5 RAM prices, demand for memory modules with extremely high capacity is likely to be low.
(ciw)
