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.

PCI-SIG this week released version 0.5 of the PCI-Express 7.0 specification to its members. This is the second draft of the spec and the final call for PCI-SIG members to submit their new features to the standard. The latest update on the development of the specification comes a couple months shy of a year after the PCI-SIG published the initial Draft 0.3 specificaiton, with the PCI-SIG using the latest update to reiterate that development of the new standard remains on-track for a final release in 2025.

PCIe 7.0 is is the next generation interconnect technology for computers that is set to increase data transfer speeds to 128 GT/s per pin, doubling the 64 GT/s of PCIe 6.0 and quadrupling the 32 GT/s of PCIe 5.0. This would allow a 16-lane (x16) connection to support 256 GB/sec of bandwidth in each direction simultaneously, excluding encoding overhead. Such speeds will be handy for future datacenters as well as artificial intelligence and high-performance computing applications that will need even faster data transfer rates, including network data transfer rates.

To achieve its impressive data transfer rates, PCIe 7.0 doubles the bus frequency at the physical layer compared to PCIe 5.0 and 6.0. Otherwise, the standard retains pulse amplitude modulation with four level signaling (PAM4), 1b/1b FLIT mode encoding, and the forward error correction (FEC) technologies that are already used for PCIe 6.0. Otherwise, PCI-SIG says that the PCIe 7.0 speicification also focuses on enhanced channel parameters and reach as well as improved power efficiency. 

Overall, the engineers behind the standard have their work cut out for them, given that PCIe 7.0 requires doubling the bus frequency at the physical layer, a major development that PCIe 6.0 sidestepped with PAM4 signaling. Nothing comes for free in regards to improving data signaling, and with PCIe 7.0, the PCI-SIG is arguably back to hard-mode development by needing to improve the physical layer once more – this time to enable it to run at around 30GHz. Though how much of this heavy lifting will be accomplished through smart signaling (and retimers) and how much will be accomplished through sheer materials improvements, such as thicker printed circuit boards (PCBs) and low-loss materials, remains to be seen.

The next major step for PCIe 7.0 is finalization of the version 0.7 of specification, which is considered the Complete Draft, where all aspects must be fully defined, and electrical specifications must be validated through test chips. After this iteration of the specification is released, no new features can be added. PCIe 6.0 eventually went through 4 major drafts – 0.3, 0.5, 0.7, and 0.9 – before finally being finalized, so PCIe 7.0 is likely on the same track.

Once finalized in 2025, it should take a few years for the first PCIe 7.0 hardware to hit the shelves. Although development work on controller IP and initial hardware is already underway, that process extends well beyond the release of the final PCIe specification.

Composable disaggregated data center infrastructure promises to change the way data centers for modern workloads are built. However, to fully realize the potential of new technologies, such as CXL, the industry needs brand-new hardware. Recently, Samsung introduced its CXL Memory Module Box (CMM-B), a device that can house up to eight CXL Memory Module – DRAM (CMM-D) devices and add plenty of memory connected using a PCIe/CXL interface.

Samsung's CXL Memory Module Box (CMM-B) is the first device of this type to accommodate up to eight 2 TB E3.S CMM-D memory modules and add up to 16 TB of memory to up to three modern servers with appropriate connectors. As far as performance is concerned, the box can offer up to 60 GB/s of bandwidth (which aligns with what a PCIe 5.0 x16 interface offers) and 596 ns latency. 

From a pure performance point of view, one CXL Memory Module—Box is slower than a dual-channel DDR5-4800 memory subsystem. Yet, the unit is still considerably faster than even advanced SSDs. At the same time, it provides very decent capacity, which is often just what the doctor ordered for many applications.

The Samsung CMM-B is compatible with the CXL 1.1 and CXL 2.0 protocols. It consists of a rack-scale memory bank (CMM-B), several application hosts, Samsung Cognos management console software, and a top-of-rack (ToR) switch. The device was developed in close collaboration with Supermicro, so expect this server maker to offer the product first.

Samsung's CXL Memory Module – Box is designed for applications that need a lot of memory, such as AI, data analytics, and in-memory databases, albeit not at all times. CMM-B allows the dynamic allocation of necessary memory to a system when it needs this memory and then uses DRAM with other machines. As a result, operators of datacenters can spend money on procuring expensive memory (16 TB of memory costs a lot), reduce power consumption, and add flexibility to their setups.

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TikTok’s Beijing-based owner ByteDance tightened its grip over its US operations over the past two years, according to company insiders, even as momentum to ban the short-video app grew in Washington.

The US government passed legislation this week aimed at forcing TikTok to divest from its parent or face a countrywide ban, but prising the viral video app from its $268 billion parent company would present a formidable challenge.

More than two dozen current and former employees told the Financial Times that TikTok has only become more deeply interwoven with ByteDance as tensions over the app’s ownership escalated.

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Today, the US Environmental Protection Agency announced a suite of rules that target pollution from fossil fuel power plants. In addition to limits on carbon emissions and a tightening of existing regulations on mercury releases, additional rules target coal ash waste left over from power generation and contaminants in the water used during the operation of power plants. While some of these regulations will affect the operation of plants powered by natural gas, most directly target the use of coal and will likely be the final nail in the coffin for the already dying industry.

The decision to release all four rules at the same time goes beyond simply getting the pain over with at once. Rules governing carbon emissions are expected to influence the emissions of other pollutants like mercury, and vice versa. As a result, the EPA expects that creating a single plan for compliance with all the rules will be more cost-effective.

Targeting carbon

The regulations that target carbon dioxide emissions have been in the works for roughly a year. The rules came in response to a Supreme Court decision in West Virginia v. EPA, which ruled that Clean Air Act regulations had to target individual power plants rather than giving states flexibility regarding how to meet broader standards. As a result, the new rules target carbon dioxide the only way they can: Plants can either switch to burning non-fossil fuels such as green hydrogen, or they can capture their carbon emissions.

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On Thursday, the US Department of Energy released its preliminary estimate for the nation's carbon emissions in the previous year. Any drop in emissions puts us on a path that would avoid some of the catastrophic warming scenarios that were still on the table at the turn of the century. But if we're to have a chance of meeting the Paris Agreement goal of keeping the planet from warming beyond 2° C, we'll need to see emissions drop dramatically in the near future.

So, how is the US doing? Emissions continue to trend downward, but there's no sign the drop has accelerated. And most of the drop has come from a single sector: changes in the power grid.

Off the grid, on the road

US carbon emissions have been trending downward since roughly 2007, when they peaked at about six gigatonnes. In recent years, the pandemic produced a dramatic drop in emissions in 2020, lowering them to under five gigatonnes for the first time since before 1990, when the EIA's data started. Carbon dioxide release went up a bit afterward, with 2023 marking the first post-pandemic decline, with emissions again clearly below five gigatonnes.

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