Tech
Cracking a long-standing weakness in a classic algorithm for programming reconfigurable chips
Researchers from EPFL, AMD, and the University of Novi Sad have uncovered a long-standing inefficiency in the algorithm that programs millions of reconfigurable chips used worldwide, a discovery that could reshape how future generations of these are designed and programmed.
Many industries, including telecoms, automotive, aerospace and particle physics rely on a special breed of chip called the Field-Programmable Gate Array (FPGA). Unlike traditional chips, FPGAs can be reconfigured almost endlessly, making them invaluable in fast-moving fields where designing a custom chip would take years and cost a fortune. But this flexibility comes with a catch: FPGA efficiency depends heavily on the software used to program them.
Since the late 1990s, an algorithm known as PathFinder has been the backbone of FPGA routing. Its job: connecting thousands of tiny circuit components without creating overlaps.
For decades, it worked so well that it became the standard. However, as circuits grew larger, engineers began encountering frustrating slowdowns and occasional outright failures. Designs that should have worked were often labeled “unroutable.”
Now, with colleagues from the University of Novi Sad and the technology company AMD, researchers from the Parallel Systems Architecture Laboratory (PARSA) in the School of Computer and Communication Sciences have come one step closer to untangling the inner workings of this classic algorithm.
In their paper, which received the Best Paper Award at the 33rd IEEE International Symposium on Field-Programmable Custom Computing Machines, they revealed why these failures happen and how PathFinder’s limits can be overcome.
Cracks in the algorithm
“In fact, it’s not surprising that PathFinder sometimes fails,” explained Shashwat Shrivastava, Ph.D. student with PARSA and first author of the paper.
“Very early on, researchers showed that the problem behind FPGA routing is extremely hard. Later, the creators of the original algorithm, together with a few collaborators, found cases where PathFinder would never succeed—but they noted such cases wouldn’t appear in practice.”
For decades, it seemed they were correct—PathFinder worked surprisingly well.
“PathFinder worked so well, in fact, that when it failed, people rarely questioned the algorithm. Instead of venturing inside to see what was going on, they tweaked its parameters, modified circuits, or switched to larger FPGAs,” added Stefan Nikolić, an EPFL alumnus and now a professor at the University of Novi Sad.
“Part of the reason for this is that it is rather difficult to understand what PathFinder is actually doing on examples of practical importance. Modern circuits are so large that their signals form veritable on-chip jungles.”
Enter the forest
“So, we really needed to look at the individual trees in that jungle,” continued Shrivastava, “and I really mean trees. Each signal—a connection that carries information between circuit components—must reach multiple destinations without overlapping other signals. FPGA routing is essentially about building one tree for each signal on the chip.”
While working on another project that relied on PathFinder, the team kept seeing results that defied intuition. At first, they blamed external factors, not the algorithm itself. Eventually, they realized they needed controlled examples: small, tricky cases where a solution definitely existed, and in which PathFinder should succeed.
“We needed real, practical examples, and lots of them, to understand what was really going on,” Shrivastava explains. “So, we built a framework to automatically extract small, hard problems from real circuits. Watching how PathFinder struggled with these helped us uncover issues that had remained hidden for a very long time.”
Power in partnership
“This breakthrough would have been much harder without industry support,” said Mirjana Stojilović, Shrivastava’s Ph.D. advisor. “From the start, we collaborated with Chirag Ravishankar and Dinesh Gaitonde from AMD. They helped us model FPGAs as close as possible to commercial devices, ensuring our findings had real-world impact.”
Once the framework was ready, things moved quickly. The team found that PathFinder often built routing trees larger than necessary, increasing the risk of overlaps. The problem came from the order in which it created and added new branches to the trees.
“In retrospect, this is intuitive, but somehow it went largely unnoticed for many years,” Shrivastava said. “Our first solution was simple: try different orders and pick the one that results in the smallest tree. Experimentally, it worked surprisingly well.”
The team is now exploring more scalable solutions. “I am especially proud that Summer@EPFL interns have been contributing significantly. One of them, Sun Tanaka, is also a co-author of the paper,” added Stojilović.
“Our discovery could reshape how millions of FPGAs are programmed and influence the design of future generations of these reconfigurable chips.”
More information:
Shashwat Shrivastava et al, Guaranteed Yet Hard to Find: Uncovering FPGA Routing Convergence Paradox, 2025 IEEE 33rd Annual International Symposium on Field-Programmable Custom Computing Machines (FCCM) (2025). DOI: 10.1109/fccm62733.2025.00060
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Cracking a long-standing weakness in a classic algorithm for programming reconfigurable chips (2025, October 3)
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Tech
Port of Tyne advances connected mobility, autonomous logistics | Computer Weekly
The North East Automotive Alliance (NEAA), alongside the Port of Tyne, autonomous driving technology provider Oxa and a consortium of leading industry and academic partners, has delivered the Port‑Connected and Automated Logistics (P-CAL) project.
The Port of Tyne is one of the UK’s major deep-sea ports handling specialised bulk and containerised products, alongside delivery logistics, and assisting growing passenger numbers via its International Passenger Terminal.
Overall, the Port of Tyne adds £658m to the local economy, supporting 10,400 jobs directly and indirectly, and as one of the UK’s largest trust ports. Fully self-financing, it runs on a commercial basis, reinvesting all of its profits back into facilities along the River Tyne for the benefit of the North East and its stakeholders.
Delivered and funded through the UK government’s CAM [Connected and Automated Mobility] Pathfinder programme, NEAA – a collaborative, industry-led cluster dedicated to fostering a competitive and sustainable environment for businesses – is working with its partners to deliver P-CAL to demonstrate autonomous container transport at the Port of Tyne. The initiative will see the deployment of a fully autonomous terminal tractor and secure mesh communication network to move containers between the dockside and the container compound, creating a UK first in waterside port automation.
P-CAL was designed to push the boundaries of autonomous logistics by deploying and validating a fully autonomous terminal tractor in a live port environment. Building on the North East’s earlier 5G CAL and V‑CAL initiatives – which looked to assess the commercial viability of deploying autonomous yard tractors on the Vantec-Nissan route in Sunderland – the project worked to move autonomous technology from proof‑of‑concept trials into a complex, safety‑critical, real‑world operational setting.
Over the course of the project, the consortium is said to have successfully designed, integrated and tested an autonomous container transport service capable of operating on a busy quayside. The scope of work included the deployment of a fully autonomous terminal tractor; a resilient mesh communication network; the capability to integrate with terminal operating systems; real‑time coordination with live crane movements; and the implementation of a cyber security framework to enable safe, remote and automated operations.
The system was developed and tested in a newly defined and highly complex operational design domain. This is said to reflect the realities of a working port environment where traffic density, variable conditions and human interaction present unique challenges.
The regional and national partnership delivering the project combined expertise across autonomous systems, logistics, cyber security, academia, legal compliance and industrial operations. The consortium believes its project has generated valuable technical, operational and regulatory insight that will inform the future deployment of CAM services across ports, logistics hubs and industrial sites nationwide.
By augmenting the capability of the existing workforce, it says it has shown that autonomous systems can take on repetitive or more hazardous tasks, allowing skilled workers to focus on higher-value roles. This is seen as particularly vital for the North East, ensuring the region remains at the forefront of industrial evolution while creating a more resilient and tech-enabled labour market.
“Delivering autonomous logistics in a live port environment has been a major step forward for the sector,” said Graeme Hardie, operations director at the Port of Tyne. “P-CAL has shown what’s possible when innovation is applied to real operational challenges, improving safety, efficiency and sustainability. The Port of Tyne is proud to have played a leading role in a project that will influence how ports across the UK and beyond approach automation.”
Oxa founder and CEO Paul Newman added: “The success of P-CAL proves how autonomy will enable the future of resilient logistics operations. Through the project, we’ve demonstrated that existing work vehicles can be turned into a digital workforce – successfully completing autonomous container movements in a dynamic quayside environment, while providing worksite intelligence necessary for real-time industrial optimisation. P-CAL provides a blueprint for how ports and industrial hubs worldwide can deploy autonomous technology to drive productivity, efficiency and safety.”
CAM Pathfinder is funded by the UK government, delivered by the Department for Business and Trade in partnership with automated mobility firm Zenzic and Innovate UK, the UK’s national innovation agency.
Zenzic programme director Mark Cracknell said: “P-CAL is a strong example of how government and industry can work together to accelerate the commercial readiness of CAM technologies. Projects like this are vital in turning innovation into deployment, creating high‑value jobs and ensuring the UK remains globally competitive in connected and automated mobility. As the project closes, the outcomes and learning from P-CAL will continue to shape future CAM initiatives, investment opportunities and policy development, both regionally and nationally.”
The next phase of the project will examine how the system performs across broader port operations, including the added pressures of multiple vehicles working alongside people, equipment and live commercial activity.
Tech
‘STAGED’: Conspiracy Theories Are Everywhere Following White House Correspondents’ Dinner Shooting
In the immediate aftermath of the attack on the White House Correspondents’ Dinner on Saturday night, influencers, pundits, and random posters lit up social media platforms like X, Bluesky, and Instagram with conspiracy theories about the attack and the alleged shooter.
Both left and right-wing accounts claimed, without evidence, that the attack was staged.
President Donald Trump, Vice President JD Vance, and dozens of other high-profile administration officials and journalists were attending the dinner at the Hilton hotel in Washington, DC, when a suspect, later identified by media reports as Cole Tomas Allen from California, allegedly ran past security towards the event. He was detained by law enforcement while the president and vice president were evacuated. Police said that they believe Cole acted alone, but did not expand on who his intended target was or what his motive may have been. “We believe the suspect was targeting administration officials,” acting attorney general Todd Blanche told NBC’s Meet the Press on Sunday morning.
On Bluesky, which has a predominantly left-leaning user base, many people simply wrote the word “STAGED” over and over again, echoing the response to the Trump assassination attempt in Butler, Pennsylvania in 2024.
On X, many claimed the shooting was staged as a way to bolster support for Trump’s plan to build a new ballroom in the White House. The president referenced the ballroom in a press conference after the incident and a Truth Social post on Sunday morning. Many prominent online Trump boosters echoed the need for the ballroom, including far-right podcaster Jack Posobiec, Libs of TikTok creator Chaya Raichik, and Tom Fitton, the right-wing activist who runs Judicial Watch.
Their quick response, conspiracy theorists claimed, was evidence of a coordinated campaign following the shooting. “Is this another staged event,” one X user asked in a post that has been viewed more than 5 million times.
Other social media users who claimed the incident was staged pointed to a Fox News clip that featured the station’s White House correspondent Aishah Hasnie speaking from the Hilton hotel. Hasnie told viewers that prior to the shooting, press secretary Karoline Leavitt’s husband allegedly told her “you need to be very safe,” before the call was cut off.
“Fox News just cut one of their reporters off as they seemed to indicate the shooting was a pre-planned false flag,” one X user wrote in a post that has been viewed more than 2 million times. Hasnie later clarified in an X post that her cell service had cut out in a location with notoriously bad service, adding: “He was telling me to be careful with my own safety because the world is crazy. He was expressing his concern for my safety.”
“I don’t want to be fomenting conspiracies,” wrote Angelo Carusone, the chair and president of Media Matters, on Bluesky about the Fox News interview. “But I mean…this was super weird. Super weird.”
Leavitt herself was also the focus of conspiracy theories after she said “shots will be fired” in an interview ahead of the dinner, referring to the jokes Trump was scheduled to deliver. Following the attack, X users claimed the comment was “strange,” “sus,” or a “curious choice of words,” while sharing memes that suggested the shooting was staged. At least one mainstream outlet appeared to amplify the conspiracy theory as well, describing Leavitt’s comment as “eerie” and “bizarre.”
Tech
Your Kindle Is Better With Accessories. Here’s Where to Start
Kindle Holders
Hate holding up your Kindle? Or struggle with chronic pain that makes holding it feel terrible? These holders will literally take the weight out of your hands.
A Freestanding Charger
Looking to keep your Kindle charged without adding another cord to the floor of your desk or bedside table? Same. Here’s a more stylish solution if you have one of the Signature editions.
A Kindle Page Turner
The hottest new item to get as a Kindle lover is a page turner. They’re especially handy for holders like the ones above, where your hands aren’t already on the device, and can make for a great accessibility accessory for readers with different needs.
My biggest irritation with these devices so far is that you have to charge them both individually, and if one runs out of battery, the whole thing is useless. I also don’t love that the turner does tend to block at least one letter while I read, and you can’t place it on the lower or upper margins since it’ll activate the menus instead of turning the page. Still, it makes reading ultra comfortable, especially for my strained wrists.
Here’s my favorite one so far, that’s been solid at holding a charge, and next I’m testing this remote ($15) with a wearable ring clicker instead of a remote.
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