Western Digital this week is previewing the industry's first 4 TB SD card. The device is being showcased at the NAB trade show for broadcasters and content creators and will be released commercially in 2025.
Western Digital's SanDisk Extreme Pro SDUC 4 TB SD card complies with the Secure Digital Ultra Capacity standard (SDUC, which enables up to 128TB). The card uses the Ultra High Speed-I (UHS-I) interface and is rated for speed Class 10, therefore supporting a minimum speed of 10 MB/s and a maximum data transfer rate of 104 MB/s when working in UHS104 (SDR104) mode (there is a catch about performance, but more on that later). WD's SD card is also rated to meet Video Speed Class V30, supporting a minimal sequential write speed of 30 MB/s, which is believed to be good enough for 8K video recording, above and beyond the 4K video market that Western Digital is primarily aiming the forthcoming card at.
For now, Western Digital is not disclosing what NAND is in the SanDisk Extreme Pro SDUC 4 TB SD card. Given the high capacity and relatively distant 2025 release date, WD may be targetting this as one of their first products to use their forthcoming BiCS 9 NAND.
And while not listed in WD's official press release, we would be surprised if the forthcoming card didn't also support the off-spec DDR200/DDR208 mode, which allows for higher transfer rates than the UHS-I standard normally allows via double data rate signaling. Western Digital's current-generation SanDisk Extreme Pro SDXC 1 TB SD card already supports that mode, allowing it to reach read speeds as high as 170 MB/s, so it would be surprising to see the company drop it from newer products. That said, the catch with DDR208 remains the same as always: it's a proprietary mode that requires a compatible host to make use of.
Western Digital has not disclosed how much will its SanDisk Extreme Pro SDUC 4 TB SD card cost. A 1 TB SanDisk Extreme Pro card costs $140, so one can make guesses about the price of a 4 TB SD card that uses cutting-edge NAND.
StorageAs LPCAMM2 adoption begins, the first retail memory modules are finally starting to hit the retail market, courtesy of Micron. The memory manufacturer has begun selling their LPDDR5X-based LPCAMM2 memory modules under their in-house Crucial brand, making them available on the latter's storefront. Timed to coincide with the release of Lenovo's ThinkPad P1 Gen 7 laptop – the first retail laptop designed to use the memory modules – this marks the de facto start of the eagerly-awaited modular LPDDR5X memory era.
Micron's Low Power Compression Attached Memory Module 2 (LPCAMM2) modules are available in capacities of 32 GB and 64 GB. These are dual-channel modules that feature a 128-bit wide interface, and are based around LPDDR5X memory running at data rates up to 7500 MT/s. This gives a single LPCAMM2 a peak bandwidth of 120 GB/s. Micron is not disclosing the latencies of its LPCAMM2 memory modules, but it says that high data transfer rates of LPDDR5X compensate for the extended timings.
Micron says that LPDDR5X memory offers significantly lower power consumption, with active power per 64-bit bus being 43-58% lower than DDR5 at the same speed, and standby power up to 80% lower. Meanwhile, similar to DDR5 modules, LPCAMM2 modules include a power management IC and voltage regulating circuitry, which provides module manufacturers additional opportunities to reduce power consumption of their products.

Source: Micron LPDDR5X LPCAMM2 Technical Brief
It's worth noting, however, that at least for the first generation of LPCAMM2 modules, system vendors will need to pick between modularity and performance. While soldered-down LPDDR5X memory is available at speeds up to 8533 MT/sec – and with 9600 MT/sec on the horizon – the fastest LPCAMM2 modules planned for this year by both Micron and rival Samsung will be running at 7500 MT/sec. So vendors will have to choose between the flexibility of offering modular LPDDR5X, or the higher bandwidth (and space savings) offered by soldering down their memory.
Micron, for its part, is projecting that 9600 MT/sec LPCAMM2 modules will be available by 2026. Though it's all but certain that faster memory will also be avaialble in the same timeframe.
Micron's Crucial LPDDR5X 32 GB module costs $174.99, whereas a 64 GB module costs $329.99.
Memory
While the new CAMM and LPCAMM memory modules for laptops have garnered a great deal of attention in recent months, it's not just the mobile side of the PC memory industry that is looking at changes. The desktop memory market is also coming due for some upgrades to further improve DIMM performance, in the form of a new DIMM variety called the Clocked Unbuffered DIMM (CUDIMM). And while this memory isn't in use quite yet, several memory vendors had their initial CUDIMM products on display at this year's Computex trade show, offering a glimpse into the future of desktop memory.
A variation on traditional Unbuffered DIMMs (UDIMMs), Clocked UDIMMs (and Clocked SODIMMs) have been created as another solution to the ongoing signal integrity challenges presented by DDR5 memory. DDR5 allows for rather speedy transfer rates with removable (and easily installed) DIMMs, but further performance increases are running up against the laws of physics when it comes to the electrical challenges of supporting memory on a stick – particularly with so many capacity/performance combinations like we see today. And while those challenges aren't insurmountable, if DDR5 (and eventually, DDR6) are to keep increasing in speed, some changes appear to be needed to produce more electrically robust DIMMs, which is giving rise to the CUDIMM.
Standardized by JEDEC earlier this year as JESD323, CUDIMMs tweak the traditional unbuffered DIMM by adding a clock driver (CKD) to the DIMM itself, with the tiny IC responsible for regenerating the clock signal driving the actual memory chips. By generating a clean clock locally on the DIMM (rather than directly using the clock from the CPU, as is the case today), CUDIMMs are designed to offer improved stability and reliability at high memory speeds, combating the electrical issues that would otherwise cause reliability issues at faster memory speeds. In other words, adding a clock driver is the key to keeping DDR5 operating reliably at high clockspeeds.
All told, JEDEC is proposing that CUDIMMs be used for DDR5-6400 speeds and higher, with the first version of the specification covering speeds up to DDR5-7200. The new DIMMs will also be drop-in compatible with existing platforms (at least on paper), using the same 288-pin connector as today's standard DDR5 UDIMM and allowing for a relatively smooth transition towards higher DDR5 clockspeeds.
Memory
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