Breaking the "Memory Wall": Optical Interconnects Emerge in GPU–HBM Packaging As a solution to the "memory wall," one of the chronic challenges in AI semiconductors, the memory and packaging industries at home and abroad are weighing an approach that decouples the GPU and high-bandwidth memory (HBM) and packages them separately. The core idea is to move the HBM—until now mounted right next to the GPU—a certain distance away, and bridge the gap with light (optics), allowing several times more HBM to be installed than is possible today. On the 22nd, a researcher at a major domestic memory maker said, "We're currently struggling to expand HBM bandwidth and capacity, so we're discussing with customers a plan to overcome the GPU's shoreline limit through optical interconnects and mount more HBM." Shoreline refers to the length of the chip's perimeter. In today's AI computing environment, the key factor dragging down compute efficiency is the data transfer speed of memory chips. While GPU performance has grown by leaps and bounds with each generation, the speed at which memory stores and supplies data has failed to keep pace—creating a structural performance barrier, the memory wall. The arrival of HBM, with its wide data pathways, put out the immediate fire, but critics continue to point out that bandwidth and transfer speeds still fall short of handling the explosive growth in AI compute. Until now, the industry has focused on stacking HBM ever higher to increase memory capacity and bandwidth within a confined footprint. But as stack counts climbed past 12 and 16 layers toward 20 and beyond, process difficulty rose exponentially. The technology hit physical limits, including the growing difficulty of meeting fixed height specifications. Vertical stacking has reached an inflection point—so much so that the JEDEC standards body has relaxed its HBM height specifications. The bigger problem is that if stack counts can't be raised, the alternative is to add more HBM horizontally around the GPU—but that, too, is impossible. In the current 2.5D packaging structure, the GPU and HBM are mounted tightly together on a single substrate. Within this structure, the number of HBM units that can be placed is strictly limited by the finite length of the GPU chip's perimeter—its shoreline. Even when more HBM is desired, there is physically no room to place it, leaving the industry in a structural deadlock. The alternative now emerging across the semiconductor industry is to separate the GPU and HBM and package them independently. It overturns the conventional chip-design principle that components must sit close together to minimize data transfer time. Instead of keeping the two chips adjacent, the approach spaces them apart and links them with overwhelmingly fast optical signals to overcome the added physical distance. Placing the HBM slightly away from the GPU within the board frees the design from the GPU's shoreline constraint. With the spatial limitation gone, far more HBM can be spread out laterally and packed into the board—several times more than today—without having to push stack heights to extremes. This means the total memory capacity and data bandwidth of the AI accelerator system would expand dramatically, on a scale incomparable to current systems. "Discussing Placing HBM Beneath the GPU"… Form Factor Could Change The industry is now producing a range of architectural design proposals over where exactly to place the HBM within the GPU board. The same memory researcher said, "Options under discussion range from broadly utilizing the space immediately around the GPU to isolating the HBM beneath the GPU board." He added, "In the latter case—isolating it beneath the GPU board—the motherboard would have to be extended lengthwise, so we're discussing even an overall form-factor change with the GPU maker." Specifically, the HBM might surround the GPU from several centimeters away, or a separate HBM zone might be created in the center of the board. "We're keeping every possibility open as we discuss the optimal layout," he said. "Nothing has been confirmed as an official roadmap yet, but as part of preliminary research toward next-generation AI accelerators, we're in talks with our partners." The outsourced semiconductor assembly and test (OSAT) industry is also watching this trend closely. An executive at a global OSAT firm said, "Optical interconnects are a clear trajectory. The only question is timing," predicting that "rack-to-rack and server-to-server links will go optical first, and then chip-to-chip connections within the board will follow." He added, "The larger units will be connected by light first, but optical research is moving so fast that it may not be that far off." Technically, the optical-interconnect technology linking GPU and HBM shares the same underlying principle as the technology connecting server to server inside a data center. The difference is the high technical barrier of shrinking optical-conversion technology—once used for communication between large pieces of equipment—down to the microscopic scale of a single board and chipset. An executive at a domestic developer of co-packaged optics (CPO) components explained, "As HBM stack heights approach their limit, the industry is discussing spreading the memory out laterally to maximize how much can physically be mounted." He added, "The principle is the same as conventional data-center optical interconnects, but HBM optical links that have to operate within a confined board space require optical components to be miniaturized to far smaller sizes and far higher integration density—so the technical difficulty is greater."

最近AI逆风的消息有点多，不过市场总是这样，坏消息都是接踵而逝的。 今天最重要的新闻是“Anthropic的Fable 5和Mythos 5被美国商务部以出口管制指令强制下架，所有用户失去访问权限，包括美国本土用户。” 事情背景：三天上线即被封杀 最初的政治指令要求“暂停所有外国国民（foreign nationals）对这两款模型的访问”，无论身在美国境内还是境外，甚至包括 Anthropic 自己的外籍员工。 一刀切： Anthropic 表示，难以在短时间内准确识别所用户国籍身份，因此只能选择一刀切，全线下线。 官方原因：国家安全 多家媒体（CNBC、Axios 等）引用美国官员的话称，“另一家公司声称成功破解了 Mythos 的安全防护机制”。商务部在致 Anthropic 的函件中，将此上升到出口管制与国家安全层面。 阴谋论 瞎猜： 1️⃣政府与Anthropic之前冲突历史：Anthropic此前坚持AI 军事用途两条红线，而国防部要求移除，矛盾升级导致国防部合同续约谈崩。 2️⃣特朗普个人对其的厌恶：今年2月27日特朗普下令联邦政府全面停用 Anthropic，理由是该公司“试图用极左价值观左右美国军队如何作战”。 3️⃣先进AI模型成为下一步的出口限制：美国把最前沿通用大模型逐步纳入类似“高端 GPU / EDA 软件”的出口控制框架，属于“AI 卡脖子”新阶段。

都说sell in May and walk away，6月2日了，我还是满仓，还是每天疯狂学习AI。依旧看好AI的未来和我的账户的未来。 但是也确实担心6月整体市场会有什么不利因素，因此在月初来梳理一下这个月的风险因子。 1️⃣6月5日，【美国5月失业率】➕非农 前值：4.30% 预期：4.30% 2️⃣6月10日，【5月CPI年率】 3️⃣6月12日，SpaceX 上市。 🌟4️⃣6月16-17日 换主席后的第一次FOMC利率决议，将同步更新2026-2027年利率路径预测 🌟5️⃣6月18日/19日，四巫日 有假日，所以实际上的四巫日应该是6.18，历史上成交量和波动率显著放大 🌟6️⃣6月24日 美光财报日 伊朗问题我觉得已经不是主要扰动因素了，对市场会有影响但不是核心因素。

The US government, citing national security authorities, has issued an export control directive to suspend all access to Fable 5 and Mythos 5 by any foreign national, whether inside or outside the United States, including foreign national Anthropic employees. The net effect of this order is that we must abruptly disable Fable 5 and Mythos 5 for all our customers to ensure compliance. Access to all other Claude models is not affected. We apologize for this disruption to our customers. We believe this is a misunderstanding and are working to restore access as soon as possible. Read our full statement: anthropic.com/news/fable-myt…

$MRVL Marvell CEO Matt Murphy: “There's still not enough logic wafers to go around.”

特朗普：今晚将严厉打击伊朗，并在某个时候夺取哈尔克岛。 不懂就问，这个岛夺下来的可能性高么？