Board Holds All Challenged Claims of Four Advanced Cluster Systems Cluster Computing Patents Unpatentable in Intel's IPRs, and Advanced Cluster Systems Appeals.

Four decisions

The Board's four final written decisions, each captioned Intel Corporation v. Advanced Cluster Systems, Inc., came from overlapping panels. In IPR2025-00913 (Paper 32, August 26, 2026), Administrative Patent Judges Karl D. Easthom, Arthur M. Peslak and Brian P. Murphy, in an opinion by Judge Murphy, held claims 1-30 of U.S. Patent 11,570,034 unpatentable (IPR2025-00913, Paper 32, at 1, 69). The same panel and author held claims 1-19 of U.S. Patent 12,021,679 unpatentable in IPR2025-00914 (Paper 31, September 1, 2026) (IPR2025-00914, Paper 31, at 1, 59). In IPR2025-00915 (Paper 32, September 23, 2026), Judges Easthom, Peslak and Scott Raevsky, in an opinion by Judge Peslak, held claims 1-30 of U.S. Patent 11,563,621 unpatentable (IPR2025-00915, Paper 32, at 1, 85). In IPR2025-00916 (Paper 32, October 20, 2026), Judges Easthom, Hung H. Bui and Raevsky, in an opinion by Judge Easthom, held claims 1-20 of U.S. Patent 11,811,582 unpatentable (IPR2025-00916, Paper 32, at 1, 86).

Intel Corporation and Advanced Micro Devices, Inc. filed the petitions together, and the November 7, 2025 decision instituting review in IPR2025-00913 is captioned with both (IPR2025-00913, Paper 16, at 1-2). The Board later terminated Advanced Micro Devices as a party in all four proceedings by an order granting a joint motion (IPR2025-00913, Paper 32, at 3 n.1); the '621 decision dates the termination January 29, 2026 and says it followed a settlement agreement between Advanced Cluster Systems and Advanced Micro Devices (IPR2025-00915, Paper 32, at 3 n.1). The decisions in IPR2025-00913, -00914 and -00916 say the Acting Director denied the patent owner's request for discretionary denial and referred the petition to the Board (IPR2025-00913, Paper 32, at 2; IPR2025-00914, Paper 31, at 2; IPR2025-00916, Paper 32, at 2 n.2). Review of all challenged claims was instituted on November 7, 2025 in IPR2025-00913, November 12, 2025 in IPR2025-00914 and November 19, 2025 in IPR2025-00915 (IPR2025-00913, Paper 16, at 49-50; IPR2025-00914, Paper 31, at 2; IPR2025-00915, Paper 32, at 2). The four cases were argued at a consolidated hearing on August 13, 2026 (IPR2025-00913, Paper 32, at 2).

The patents and the prior art

All four patents are titled Cluster Computing, and the Board applied June 13, 2006 as the earliest possible priority date (IPR2025-00913, Paper 32, at 52; IPR2025-00915, Paper 32, at 16; IPR2025-00916, Paper 32, at 4 n.3). As the decisions describe them, the patents concern nodes, each running a single-node kernel that evaluates mathematical expressions, that communicate with one another through cluster node modules so the group can work as though it were a single computer (IPR2025-00913, Paper 32, at 4-7; IPR2025-00915, Paper 32, at 3-6). The '034 and '679 claims recite a first node with a user interface that distributes calls to a second node, which passes a result to a third node, which returns a further result to the first node (IPR2025-00913, Paper 32, at 8-9; IPR2025-00914, Paper 31, at 8-9). The '621 and '582 claims recite three processors, each with a kernel and a cluster node module (IPR2025-00915, Paper 32, at 6-7; IPR2025-00916, Paper 32, at 6-7).

Every ground rested on the same printed publications: a 1997 supercomputing conference paper titled MultiMATLAB: Integrating MATLAB with High-Performance Parallel Computing, a 1996 university technical report titled MultiMATLAB: MATLAB on Multiple Processors, and a 2001 hardware planning manual for the parallel computer system those papers used, titled RS/6000 SP: Planning Vol. 1, Hardware and Physical Environment. The '034 and '679 grounds added a 2001 manual titled Operation and Use, Volume 1, Using the Parallel Operating Environment, with the 1994 MPI: A Message-Passing Interface Standard added for '034 claims 26 and 29. The '621 and '582 grounds added the MPI standard, with the operating environment manual added for two dependent claims in each (IPR2025-00913, Paper 32, at 9-10; IPR2025-00914, Paper 31, at 9; IPR2025-00915, Paper 32, at 8; IPR2025-00916, Paper 32, at 8). Each challenge was an obviousness ground under pre-AIA 35 U.S.C. 103(a).

The Board's reasoning

In the '034 case, the Board had ordered the parties at institution to construe the phrase a hardware processor with a plurality of processing cores (IPR2025-00913, Paper 16, at 13-14, 49-50). Advanced Cluster Systems argued that the phrase requires a single multi-core processor, so that a node built from several single-core processors, as in the 2001 hardware manual, does not meet it. The Board disagreed and held that the plain and ordinary meaning is one or more single-core or multi-core microprocessors with a plurality of processing cores, because the claims recite a processor with cores rather than cores within a single chip package and the specification describes a processor as one or more single-core or multi-core microprocessors (IPR2025-00913, Paper 32, at 13-19, 26-27).

The Board found a motivation to combine the two MultiMATLAB papers, which it described as the work of the same university research group about a year apart, the later paper building on the earlier one, and it rejected the patent owner's argument that the later paper teaches away from the earlier design (IPR2025-00913, Paper 32, at 27-35; IPR2025-00914, Paper 31, at 18-26; IPR2025-00915, Paper 32, at 33-44).

Advanced Cluster Systems argued that the references return only screen output, not computed data, to the user's node, and so do not teach the claimed path of results from node to node and back. The Board held that the claims require communicating a result, not data for further use, and that the references' example script, in which each process doubles a value and passes it to the next, with output sent to the process the user works in, teaches the claimed order of operations (IPR2025-00913, Paper 32, at 35-51; IPR2025-00914, Paper 31, at 26-42; IPR2025-00916, Paper 32, at 65-77). The Board noted that the patent owner agreed at the hearing that its distinction rested on screen output not being data (IPR2025-00913, Paper 32, at 45; IPR2025-00916, Paper 32, at 69).

The Board treated the argument that the references route results through a central master, and so lack the claimed peer-to-peer architecture, as raised for the first time in sur-reply and unsupported by evidence (IPR2025-00913, Paper 32, at 49-50 and n.24; IPR2025-00914, Paper 31, at 40 and n.21), and in the '582 case it held that the combination meets dependent claim 15's peer-to-peer limitation in any event (IPR2025-00916, Paper 32, at 79-81). In the '621 case it held that the references teach cluster node modules that transmit tasks to one another without going through a master node (IPR2025-00915, Paper 32, at 67-70), and that placing two processors on the same die, as dependent claims 20 and 25 recite, would have been an obvious engineering choice as of the June 2006 priority date, rejecting the patent owner's argument that the relevant time frame was the mid-1990s (id. at 75-79).

The Board also held that all five references were publicly accessible before June 13, 2006 and qualify as printed publications, relying in part on a librarian's declaration submitted with Intel's reply and on the Federal Circuit's decision in VidStream LLC v. Twitter, Inc., and it found that the patent owner had waived its admissibility objections by not filing a motion to exclude (IPR2025-00913, Paper 32, at 51-69).

The notices of appeal

On October 27, 2026, Advanced Cluster Systems, Inc., as patent owner, gave notice that it appeals to the Federal Circuit from the final written decision entered August 26, 2026 in IPR2025-00913 (Paper 32), determining claims 1-30 of the '034 patent unpatentable, and from all underlying orders, decisions, rulings, findings and opinions (IPR2025-00913, Paper 33, at 1). The notice states that the issues may include the Board's construction of the hardware-processor limitations of independent claims 1, 25, 28 and 30, its findings on communication of results between nodes, its reliance on expert testimony, its disposition of the peer-to-peer arguments, including on waiver grounds, its printed-publication rulings, and the Board's compliance with the Administrative Procedure Act (id. at 1-2).

On October 30, 2026, Advanced Cluster Systems gave notice that it appeals from the final written decision entered September 1, 2026 in IPR2025-00914 (Paper 31), determining claims 1-19 of the '679 patent unpatentable, and listed similar issues, including the Board's treatment of the peer-to-peer architecture limitation of claim 1 (IPR2025-00914, Paper 32, at 1-2). Each notice states that a copy and the docketing fee were being filed with the Federal Circuit clerk (IPR2025-00913, Paper 33, at 3; IPR2025-00914, Paper 32, at 3).

The Texas cases

The decisions list two Western District of Texas cases as related: Advanced Cluster Systems, Inc. v. Intel Corporation, No. 7:24-cv-00245, and Advanced Cluster Systems, Inc. v. Advanced Micro Devices, Inc., No. 7:24-cv-00244 (IPR2025-00913, Paper 32, at 3; IPR2025-00915, Paper 32, at 3; IPR2025-00916, Paper 32, at 2-3). Both dockets show the cases filed September 26, 2024. The Intel docket shows a claim construction order on September 26, 2025 (ECF 87), a motion to stay filed February 2, 2026 and an order on it February 3, 2026 (ECF 102 and 103), an order entered August 27, 2026 with which the case was terminated (ECF 105), and a status report filed September 1, 2026 (ECF 106). The Advanced Micro Devices docket shows a stipulation of dismissal on January 21, 2026 and an order dismissing the case on January 22, 2026 (ECF 83 and 84).

What to watch next

Watch for the Federal Circuit docket numbers and briefing in the appeals from the '034 and '679 decisions, and for any notice of appeal from the '621 and '582 decisions. The appeals can end at any time, including by settlement or voluntary dismissal.