ajdecon

@ajdecon

Building HPC systems for researchers, currently at IonQ. Formerly NVIDIA, FB, LANL; and before that, materials physics. Perpetually a bit confused. As always opinions are mine. He/him. 🏡: Denver, CO 🌐: Signal: @ajdecon.42

886 Following1,860 Followers1,424 Posts

Bluesky

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ajdecon@ajdecon· 3d

I continue to be impressed with all the advances in weather models lately. Tons of great work being done in this space.

This collaborative work brought together
Al researchers and engineers at Google DeepMind and Google Research, with expert forecasters at the National Hurricane Center (NHC), the Cooperative Institute for Research in the Atmosphere (CIRA), the UK Met Office, and weather agencies around the world.
Our research has already had real-world impact. During the 2025 hurricane season, our model helped the NHC to make a historic forecast for Hurricane Melissa by predicting the storm's rapid intensification and landfall in Jamaica.
This enabled the NHC to issue an advance warning, giving teams on the ground critical time to prepare. This year, we continue to work together and are now predicting 1,000 possible scenarios for each cyclone to help support forecasters in their decision-making.

ajdecon@ajdecon· 9d

This little creature hasn’t let me get a full night of sleep in a week. So, yeah, DON’T

A mini golden doodle puppy running at the camera

ajdecon@ajdecon· 13d

“AI datacenter” defined as a 20 MW site, 20 kW racks, any direct liquid cooling. I swear I was running systems that large over a decade ago, and no they weren’t running chatbots.

(2) ARTIFICIAL INTELLIGENCE DATA CEN-TER.—The term "Artificial Intelligence Data Cen-ter" means buildings, equipment, structures, and other stationary items, such as server racks, that—
(A) are located on a single site or on con-tiguous, adjacent, or otherwise connected sites;
(B) are owned or operated by the same en-
tity or by any entity that controls, is controlled by, or is under the common control of that enti-ty, regardless of whether the site is a single-oc-cupant or multi-occupant facility; and
(C)(1) are used for the development or op-
eration of artificial intelligence models at scale;
Or
(il) (1) have a maximum rated power capac-
ity or total peak power load in excess of 20
megawatts;

(II) are designed or equipped to— (aa) deliver 20 kilowatts or more of
electrical power to a single server rack; or
(bb) utilize cooling systems that cir-
culate liquid to individual hardware components or submerge electronic hardware in liquid.
(3) ASSOCIATED INFRASTRUCTURE.—The term
"associated infrastructure" means any physical infrastructure built to serve an Artificial Intelligence Data Center, including but not limited to transmission lines, power substations, natural gas plants, natural gas pipelines, backup generation facilities, and water pipelines and cooling infrastructure.
(4) FEDERAL LAND.—The term "Federal
land”ー
(A) means all land owned or managed by the United States, including land under the jurisdiction of the Department of Defense; and
(B) does not include land held in trust by the United States for the benefit of an Indian
Tribe or member of an Indian Tribe.

ajdecon@ajdecon· 21d

This is a wild statement, and afaict refers to section 219 which establishes a defense tech R&D partnership. Which doesn’t seem like something we should do! But isn’t “merge parts of our military with the IDF”. www.military.com/massie-reviv...

The provision, which was renumbered from Section 224, would establish a United
States-Israel Defense Technology
Cooperation Initiative. It would require the defense secretary to appoint an official responsible for coordinating joint research, testing, weapons development, technology integration and industrial cooperation between the two countries.
The initiative would cover areas including missile defense, artificial intelligence, autonomous systems, cybersecurity, quantum technology, electronic warfare and weapons co-production.

ajdecon@ajdecon· 22d

I would visit Jurassic Park (after updating my life insurance) I would hitch a ride to Mars (but not with Musk) I would visit the ocean floor in a (well-built) submarine Some chances you just don’t skip!

A four-panel comic strip drawn in a simple, stick-figure style that follows a sequence of events. In the first panel, a stick figure reaches toward a rectangular object with the word "PULL" written above. The second panel shows the figure experiencing an electric shock, indicated by jagged lines and the word "ZAP." The third panel depicts the figure standing still and looking contemplative. The final panel splits into two separate paths: on the left, labeled "NORMAL PERSON," the figure has a thought bubble that reads, "I GUESS I SHOULDN'T DO THAT"; on the right, labeled "SCIENTIST," the figure has a thought bubble that reads, "I WONDER IF THAT HAPPENS EVERY TIME."

ajdecon@ajdecon· 28d

One thing I found confusing is that Liz’s DID document shows a PLC in alsoKnownAs. Do you know if there’s some kind of aliasing mechanism between the two methods, or is something else going on?

{
"@context": [
"https://www.w3.org/ns/did/v1",
"https://w3id.org/security/multikey/v1",
"https://w3id.org/security/suites/secp256k1-2019/v1"
],
"id": "did:web:lizthegrey.com",
"alsoKnownAs": [
"at://web.lizthegrey.com",
"did:plc:i4tfenpfog244rxry5uz4vtk"
],

ajdecon@ajdecon· Jul 7

I definitely paused at the title, but this is otherwise quite a good article.

these people matter.
They're real. They exist, and they have hopes and dreams and lives of their own, and it's a miracle that any one of us exists. And I think that matters more than any utopian dream of social homogeneity, or academic theorizing about the idealized state of society.

ajdecon@ajdecon· Jul 3

A photo from our drive from WA to CO several days ago. The photo doesn’t capture how vivid and bright the rainbow truly was.

ajdecon@ajdecon· Jul 1

Ok yeah this is a fun version of the political compass idea. The results, they do not shock me 😁

Committed Libertarian Left
You want equality without a boss. Mutual aid, shared ownership, as little coercion as you can manage.

ajdecon@ajdecon· Jun 30

This post on age verification with zero knowledge proofs is really interesting, and TBQH I think it shows how *difficult* it will be to do online age verification in a privacy-preserving manner. blog.vrypan.net/2026/06/29/2...

What privacy advocates should focus on

None of this makes the EU system automatically safe. A privacy-preserving architecture can still be ruined by bad implementation.

Things that would break the promise:

- stable identifiers reused across websites
- the issuer being contacted on every age check
- centralized logs of verification events
- wallet telemetry recording which relying parties requested proofs
- websites demanding more attributes than necessary
- weak wallet security
- poor UX that nudges users into oversharing
- browser or device fingerprinting that links otherwise anonymous proofs
- revocation checks that reveal where credentials are used
- closed, unaudited national implementations

ajdecon@ajdecon· Jun 30

Ha! the Yglesias comparison feels rude, but the substance is accurate. “Bullish in a spreadsheet way, not a singularity way” sums it up pretty well.

YOU ARE...
The B2B SaaS Consultant
patron saint: Matt Yglesias
AI will quietly boost total factor productivity by some single-digit percentage and you think that's actually a huge deal, wonkily speaking. You're bullish in a spreadsheet way, not a singularity way. You've explained the Jevons paradox to someone who didn't ask.

ajdecon@ajdecon· Jun 24

Maddie considers a chess opening

A white and brown puppy sits on a chair and looks at the camera. In front of her, on a coffee table, is a chess set partway through an opening

ajdecon@ajdecon· Jun 23

Also, preemptively: Phryne, the cat depicted in the art is still doing just fine.

A calico cat sitting in a wooden cat bed mounted on a desk

ajdecon@ajdecon· Jun 23

If you’re like me, changing profile pictures can really throw you! Especially if the previous picture was in use for a long time. So. Since I changed it today, here are the old and new pictures as a reference. 😉

A cartoon-style depiction of a bearded man with glasses and a calico cat.

A photo of a bearded man, wearing glasses and a flat cap, in front of an expanse of blue water with an island in the near distance

ajdecon@ajdecon· Jun 23

Coming up on the end of our month on Whidbey and I kinda can’t imagine leaving. Absolutely beautiful relaxing month.

Sunlight shimmering on the bay, with trees in the foreground and on the other side of the bay

A golden doodle in a park with marine layer fog burning off

ajdecon@ajdecon· Jun 16

Benny would like to know why he doesn’t get a beer

A golden doodle with a bandanna laying in some bright green grass, looking up at the camera with a mournful expression

ajdecon@ajdecon· Jun 14

Summers in the Pacific Northwest are just absolutely beautiful.

A wide scenic view under a clear blue sky shows a grassy field and a manicured lawn separated by a line of bushes. Tall evergreen trees stand along the edge of the field, framing a glittering body of water with a forested shoreline in the far distance.

ajdecon@ajdecon· Jun 14

We had a bunch of these, but this may have been my favorite.

ajdecon@ajdecon· Jun 10

Lazy afternoon with the dogs

A coffee table with a chessboard, a kindle, a notebook, and whiskey

A leather chair with a puppy sleeping on a blanket

A large goldendoodle asleep at the end of a couch

ajdecon@ajdecon· Jun 4

A pretty chill afternoon

A large goldendoodle snoozes in grass, while a puppy lays right next to him with her head up looking at the camera

ajdecon@ajdecon· Jun 2

Hello Seattle friends! I’m in the area during the month of June, staying on Whidbey Island. Mostly I’m planning to chill with my partner and dogs, but if any friends or mutuals would like to get a coffee and say hello, let me know!

A dog wades into the water under a clear blue sky

ajdecon@ajdecon· May 24

Beautiful Sunday afternoon to hang out in the back yard.

A view of an outdoor table with a floral tablecloth. A chess set sits in front of a Kindle with a chess scenario open. Also on the table is a can of Avery White Rascal beer, a bottle of San Pelligrino sparkling water, and a vase with flowers.

ajdecon@ajdecon· May 24

Always nice to stop at the local brewery on a Sunday walk

ajdecon@ajdecon· May 21

I think they want things

Two golden doodles stare up into the camera

ajdecon@ajdecon· May 19

As an #HPC admin who has managed Slurm clusters with >20k nodes before, I can’t resist a moment of snark. But there are genuine reasons you would want to do this with k8s, eg managing training, inference, and general service workloads in the same control plane.

$Invincible meme, look what they need to mimic a fraction of our power. At the top is k8s multi-cluster orchestration. At the bottom is HPC schedulers.$

ajdecon@ajdecon· May 19

The topology management section also seems pretty rudimentary, and from an ML training perspective I struggle to see how it could manage complex overlapping network domains. (Eg NVLink + a compute fabric with locality constraints) But again… might be assuming this requires additional customization?

8. Topology handling
Two kinds of topology constraint, both passed through to the autoscaler. The scheduler handles final pod placement in both cases.
Co-location (the Same operator)
Same is the only new concept in the APl. During roll-up, for CRs needing co-location, the operator adds {key:
"topology. kubernetes.io/rack", op: "Same"}. The autoscaler provisions all nodes in one topology domain.
{key: "topology.kubernetes.io/rack", op: "Same"} → all nodes must share a rack. Autoscaler picks whicł
{key: "topology.kubernetes.io/zone", op: "Same", value → must share a zone, but only these two are candidate
{key: "topology.kubernetes.io/zone", op: "In", values: → each node independently in one of these zones. Can
Same only exists in the protobuf. The CRD uses standard operators.
The operator translates during roll-up.
Spread (topology spread constraints)
Copied from the pod's topologySpreadConstraints. Three fields pass through: topologyKey, maxSkew, whenUnsatisfiable.
DoNotSchedule : Don't provision nodes if spread can't be satisfied
- the scheduler will refuse to place pods on them.
ScheduleAnyway : Try to spread, but provision regardless.
Without this information, the autoscaler might provision all nodes in one zone. With one topology domain, maxSkew is trivially zero and DoNotSchedule is vacuously satisfied - incorrect with no unschedulable pods to trigger correction.

ajdecon@ajdecon· May 16

Ran across this site on my feed. Entirely unsurprising results. findmypolitics.com

Liberal Progressive: Centre-Left / Civil Libertarian

Economic: 34% left-wing
Social: 75% libertarian
Civil Liberties: 84% pro-liberty
Governance: 44% globalist
System trust: 44% high trust

ajdecon@ajdecon· May 16

Yesterday was my last day at NVIDIA! Seven VERY busy years, getting to work with some highly skilled, excellent and thoughtful humans. For now, I’m taking a break: June is a vacation month and I plan to spend more time walking the dogs than thinking about computers. After that? Watch this space!

Polyphe, one of the last big clusters I helped to design and build while at NVIDIA.

ajdecon@ajdecon· May 14

Note that, indeed, Bluesky the corporation regards the protocol as their product more than the app. This ecosystem is what they’re trying to build and enable. It’s not just Blacksky either (tho they have done amazing work!). There are more and more ATproto apps popping up lately.

If Bluesky-the platform and the corporation-vanished tomorrow, Blacksky would continue on unscathed. Its users would still post, still follow each other, still see their feeds, still be moderated according to Blacksky's policies rather than anyone else's. And they would still, because the protocol is open and the data is portable, be able to interact with everyone on the network who chose to remain reachable to them.

ajdecon@ajdecon· May 13

Ok actually it’s probably this one