中国与日本半导体：内存接口芯片引子：乘上AI浪潮

Memory Interface Chip Primer: Riding on the agentic AI boom We initiated coverage on Montage in April (initiation report and deck) where we discussthe opportunity for memory interface chip vendors driven by agentic AI. In this primer, weprovide a comprehensive overview of the industry's growth drivers, competitive dynamics,and investment implications to help investors navigate the sector. Updated models can bedownloaded here: Memory Interface Chip Industry Model and Montage Model.ReiterateOutperform on Montage, PT revised up from HKD 320 to 520 in H-share and CNY 220 to400 in A-share.Reiterate Outperform on Renesas. Qingyuan Lin, Ph.D.+852 2123 2654qingyuan.lin@bernsteinsg.com David Dai, CFA+852 2918 5704david.dai@bernsteinsg.com Francis Ma+852 2123 2626francis.ma@bernsteinsg.com Memory interface chips are a direct and amplified beneficiary of the server CPURenaissance driven by Agentic AI.As the industry shifts from GPU-centric trainingtoward inference-heavy agentic AI deployments—where the CPU reclaims its role asorchestrator of multistep, sequential tasks—server CPU volumes are poised to growstructurally faster than expected (our CPU report), and the role of memory interface chipbecomes increasingly important when the DRAM capacity and bandwidth per CPU grows.We project the global memory interface chips TAM to reach USD 20Bn by 2030 (3x of ourprevious projection) at 65% CAGR (vs 32%), driven by three reinforcing tailwinds: risingserver CPU volume, increasing DRAM package count per CPU, and higher interface chipcontent per package through the MRDIMM upgrade. Kai Zhang+852 2123 2665kai.zhang@bernsteinsg.com Jack Lin+852 2123 2683jack.lin@bernsteinsg.com Juho Hwang+81 3 6777 6980juho.hwang@bernsteinsg.com MRDIMM penetration is an important driver, as interface chip value per MRDIMMmodule is roughly 10× that of RDIMM.Each MRDIMM adopts a "1 MRCD+10 MDB"architecture, versus just one RCD in standard DDR5 RDIMM. We project MRDIMMpenetration to reach 25% (vs 20% previously) of global server DDR DIMM shipments by2030, driven by the bandwidth improvement MRDIMM delivers. The adoption hurdle ismanageable: MRDIMM premium is only about 10% of the current 128GB RDIMM price, andthis gap narrows further as rising DRAM die prices reduce the premium. Carmine Milano, CFA+44 20 7762 1857carmine.milano@bernsteinsg.com The competitive landscape for core memory interface chips is a textbook oligopolythat drives high margin.Montage, Renesas, and Rambus (RMBS, not covered) collectivelycontrol 90%+ of global share, protected by rigorous JEDEC qualification cycles and deepco-development ties with DRAM IDMs and CPU platforms. The chip is crucial for thepackage performance but takes only LSD% of the package price, customers have very lowincentive to shift to new vendors and are willing to offer high margin to secure the quality.The three vendors compete neck-and-neck on the RDIMM roadmap, while Renesas andMontage hold early-mover advantages in MRDIMM. The complementary supporting chipssegment is more fragmented, where Renesas leads thanks to its analog heritage. We favor all three leading suppliers, as market has not fully priced in upside fromCPU acceleration and MRDIMM adoption.We raise Montage TP to CNY400/ HKD520for A-/H-Share, supported by CPU-driven demand across both its memory interfaceand PCIe businesses, as well as share gains from CXMT expansion.Renesas’s memoryinterface is at a scale similar to Montage’s despite contributing only 6% of it revenue, yetits market cap is only 25% above Montage's; it appears significantly undervalued, andmanagement’s guidance for 20-30% growth CAGR for this business is too low.Rambusbenefits across both interface chip products and memory controller IP royalties; its smallerrevenue base and market cap give it the largest potential upside elasticity. BERNSTEIN TICKER TABLE PRICE TARGET CHANGE / ESTIMATE CHANGE IN BOLD INVESTMENT IMPLICATIONS Since April the shares of Montage, Rambus, and Renesas have rallied for several months, reflecting strong investor interest inthe memory interface chip sector as the CPU vendors comment on strong server CPU demand. Over the past month, however,their share prices have corrected 10–30% from peak levels as investors increasingly question whether valuations havebecome overstretched. We expect sentiment to remain weak in the near term, reflecting continued softness in memory-relatedsentiment, profit-taking following the strong share price rally, and concerns around weak near-term earnings due to substrateshortage for Montage and Rambus. From a tactical perspective, investors may prefer to remain on the sidelines for the nearterm. However, we expect that on a 12-month horizon, as the MRDIMM penetration continue to increase, when investor start tolook into the potential upsides in 2028 then the stocks could work again, therefore long-onlys should look to buy the dip whenthe market corrects. Montage Technology:We rate Montage Technology asOutperfo