Glenn K. Lockwood
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glennklockwood.com
Glenn K. Lockwood
@glennklockwood.com
I am a supercomputing enthusiast, but I usually don't know what I'm talking about. I post about large-scale infrastructure for #HPC and #AI.
November 5, 2025 at 5:41 PM
I never heard of Socks Club before this year, they seem to be crushing it. I now have WEKA socks, VAST socks, and Anyscale socks all from them. Made in the USA, and pretty high quality for conference swag. I should invest.

CC @addisonsnell.bsky.social my fellow sock aficionado.
November 5, 2025 at 4:57 PM
Satya posted a video showing off their GB300 which appears to be in a previous-gen, air-cooled DC. Look at the size of the two liquid-air heat exchangers required to support a single ~120kW NVL72 rack. Not as ridiculous as the 4x used by Meta, but man, this looks silly compared to traditional #HPC.
October 11, 2025 at 6:32 PM
Time for my vacation in North Dakota to come to an end. I can fly to either Denver or Denver. I guess I’m flying to Denver.
September 28, 2025 at 6:26 PM
Here is the lutefisk (bottom right) that I had for dinner. If you don’t know what that is, it’s worth looking up. Sounds way worse than it tastes.
September 26, 2025 at 12:32 AM
Here’s the klub I had for lunch. Hard to see the ~cm of melted butter at the bottom of the container.
September 25, 2025 at 1:02 AM
I’m in North Dakota this week celebrating Scandinavian heritage.

That liquid on top is butter.
September 24, 2025 at 10:32 PM
Also, check out the earthworks being done in preparation for their upcoming Doudna system. Going to require a lot of cooling!
September 19, 2025 at 11:53 PM
Visited some of my old pals at @nersc.bsky.social this afternoon. It feels like a lot has changed, but at the same time, it’s the same old place. I do miss working here, but am glad I now get a chance to visit under the auspices of my new role at VAST.
September 19, 2025 at 11:50 PM
I assume this +$4b buildout is the huge site next door to the just-disclosed Fairwater site. If you consider this a single "datacenter," this is what a ~gigawatt AI supercomputer is going to look like in 2027.
September 18, 2025 at 6:15 PM
September 8, 2025 at 6:19 PM
My first taste of loss since leaving Microsoft came last night 😢
August 22, 2025 at 4:40 PM
Getting on a plane for VAST for the first time on Monday. But I’m not so sure about the destination 🥵
August 9, 2025 at 5:03 PM
GPT-5 is cool and all, but it's still not to be trusted. Didn't take me long to get "PhD-level" made-up facts.

What really distinguishes "PhD-level" is the ability to critically think, be skeptical, and stand behind the information you put forward. GPT-5 still ain't there.
August 9, 2025 at 12:49 AM
One thing I really enjoy about working at VAST (or perhaps that I enjoy about not working at Microsoft) is that I can go out and talk to people again as part of my job. Here’s a view from where I got to spend my afternoon today.

#notHPC #butthatsok
August 5, 2025 at 5:21 AM
Typical hyperscale DLC designs require huge liquid-air heat exchangers adjacent to every rack without facility water, and even then, most GB200 is still 15% air, so racks are spaced apart to ensure enough volume is available. Here is a MAIA100 liquid-air hx; the GB200 one is even bigger.
July 16, 2025 at 9:44 PM
I am a sucker for photos of cool #HPC infrastructure, and here is a dense GB200 NVL72 cluster going up somewhere in Canada (I think). Impressive to see this many racks in row; the DC must have facility water which is still uncommon in hyperscale.

Source: www.linkedin.com/posts/5cai_h...
July 16, 2025 at 4:41 PM
Now that I am not beholden to an employer, I can say whatever I want online!

But I really never held back before, so I don’t have much to spill now. I am glad to get the corporate device management off my phone though.
July 9, 2025 at 10:46 PM
I turned in my badge and was escorted from the building, so I guess that means I am officially unemployed! For a few days at least.
July 9, 2025 at 10:12 PM
Photos of a new, big, naked Cerebras cluster in Oklahoma appearing on the socials today. Pretty neat. Wonder if this is another G42 install.
June 28, 2025 at 5:10 PM
June 28, 2025 at 4:17 PM
I just found a corporate blog post that called me “an extremely intelligent Microsoft engineer.” Very flattering! 🤩

But that’s also not what I said/wrote (source: blog.glennklockwood.com/2025/02/llm-...). Maybe misattribution is the highest form of flattery.
June 28, 2025 at 3:53 PM
I had no idea Fortran for deep learning was anything but a joke, but this talk from LBL is interesting. Apparently it can be really fast (cf. pytorch), and many modern Fortran features may map nicely to the algs used in ML/DL.

#ISC25
June 13, 2025 at 10:29 AM
Nice work from U Bologna: Tenstorrent has a good, if a bit complicated, story around efficiency (performance and perf/watt. What’s not shown in these slides is the massive price difference. At $699, I kinda want to buy one of these accelerators to mess with.

#ISC25
June 13, 2025 at 10:15 AM
Easy misconception is that AI people can just downcast from high precision to low precision and life is good. Reality is that there’s a bunch of gnarly mixed precision going on that’s a lot of work and complexity to implement usefully. Nobody’s enjoying a free lunch in either HPC or AI.

#ISC25
June 13, 2025 at 8:53 AM