wickberg

6 ms·

1.
by wickberg 11mo ago
Newer airports usually try to have space, that's the only thing helping with the physics involved here. Older airports might have EMAS [1] retrofitted at the ends to help stop planes, but that's designed more for a landing plane n
2.
by wickberg 2y ago
The US technician exam has almost zero relevance to operating a radio, outside of some legal reminders to broadcast your call sign every 10-minutes. I'll second the recommendation for hamstudy.org. 90 minutes cramming that the night be
3.
by wickberg 2y ago
That's 200Gbps from that card to any other point in the other 9,408 nodes in the system. Including file storage. Within the node, bandwidth between the GPUs is considerably higher. There's an architecture diagram at < https:&#x
4.
by wickberg 2y ago
Frontier is 4x 200Gbps links per node into the interconnect. The interconnect is designed for 540TB/s of bisection bandwidth. < https://icl.utk.edu/files/publications/2022/icl-utk-1570-202... > Bisec
5.
by wickberg 2y ago
"Aurora" at Argonne National Labs is intended to be a bit bigger, but has suffered through a long series of delays. It's expected to surpass Frontier on the TOP500 list this fall once they some issues resolved. El Capitan at
6.
by wickberg 2y ago
On a node-level, usually these are aiming for around 90-95% allocated. Note that, compared to most "cloud" applications, that usually involves a number of tricks at the system scheduling level to achieve. At some point, in order t
7.
by wickberg 2y ago
Almost no modern systems are running Torus these days - at least not at the node level. The backbone links are still occasionally designed that way, although Dragonfly+ or similar is much more common and maps better onto modern switch silic
8.
by wickberg 2y ago
Frontier runs unclassified workloads. Other Department of Energy systems, such as the upcoming "El Capitan" at LLNL (a sibling to Frontier, procured under the same contract) are used for classified work.
9.
by wickberg 2y ago
I know Golang has their own implementation of sd_notify(). For Slurm, I looked at what a PITA pulling libsystemd into our autoconf tooling would be, stumbled on the Golang implementation, and realized it's trivial to implement directly
10.
by wickberg 3y ago
Cluster authentication actually remains the sore point for all interactions - for most systems the least-common denominator remains whether one can SSH into a login node. At which point the main job commands - sbatch/squeue - are prett
11.
by wickberg 8y ago
Slurm is endian and word-size agnostic; there's nothing about the POWER9 platform that would be insurmountable for it to run on. There are occasionally some teething issues with NUMA layout and other Linux kernel differences on newer p
12.
by wickberg 8y ago
In terms of KNL deployments, LANL's Trinity system (#9 on June 2018) is slightly larger. Trinity has 9,984 KNL nodes, vs 9,688 in Cori.
13.
by wickberg 8y ago
I use it on my motorcycle in the US, but there are some major pain points. I have a Bluetooth headset in my helmet, so I can hear the directions... which are usually close enough. But you still do get some occasionally confusing voice promp
14.
by wickberg 8y ago
I don't have any customer data on hand at the moment, but I'd roughly describe it as basic scheduling on strict priority order getting the system to 80+% usage, and then backfill boosting that up to 90%+. Careful backfill tuning,
15.
by wickberg 8y ago
If you're the one that came up with the idea of the "quiesce", I feel like you owe quite a few of us in the systems software community a beer or three...
16.
by wickberg 8y ago
99% is a bit higher than most systems expect to run at - any mix of job sizes in the queue will tend to leave small gaps when nodes need to stay idle until jobs "fit" perfectly again. 95% is a pretty common target for these larger
17.
by wickberg 9y ago
Part time PhD's are rare - most professors need their grad students to be working on their grant-related research projects as RAs. That work is then used as the basis for your dissertation. As a part time PhD student you'd need to
18.
by wickberg 9y ago
It's even more subtle than that - about half of Connecticut is heavily involved with business in NYC, and would probably be quite unwilling to jump an hour over. To a lesser extent, south-western Vermont is economically linked to the A
19.
by wickberg 9y ago
The Netflix Open Connect appliances are custom-built hardware they send out to ISPs. [1] As evidenced by their heroic efforts to tunes performance[2], and their careful choice of hardware[3], they could certainly deploy POWER if they chose
20.
by wickberg 9y ago
Indeed, it does look like the set she's holding is one of three that were sold in the auction. If Adafruit has actually acquired the brand, this is certainly an odd way to go about announcing it. I could see this having been a joke tha
21.
by wickberg 9y ago
The Xeon... maybe. The Phi... definitely slower. The single-core performance is very low, and there are usually at least a few linking stages in any source code compilation that collapse the process down to a single thread - you can't
22.
by wickberg 10y ago
SchedMD | Software Engineer | Lehi, Utah | ONSITE https://www.schedmd.com SchedMD are the developers of the open-source Slurm resource manager (aka job scheduler) used by roughly half of the top500 systems. We're looking fo
23.
by wickberg 10y ago
This is meant as a competitor, at least in the high-performance computing market, to Intel's Xeon Phi (aka Knights Landing) based systems which will start including their OmniPath network fabric on-die (based on QLogic's Infiniban
24.
by wickberg 11y ago
STS was never fully automated, they would have needed to install a temporary cable that allowed the landing gear to be automatically deployed. It looks like https://en.wikipedia.org/wiki/STS-3xx has details on this cab
25.
by wickberg 12y ago
Mix in the just-announced CVE-2014-9322, among others, and you have a fairly obvious path to root. Generally, at any time, it's safer to assume there's at least one active local root exploit in any system.
26.
by wickberg 12y ago
I wouldn't rely on the Watson connection to influence their chip division strategy. It's not something they spread around, but from what I recall from a Q+A with IBM engineers the Watson prototype was developed on AMD xSeries serv
27.
by wickberg 14y ago
I was working on the same lines, and managed to bump it up to a score of 106: #define P printf( main(n){(n%3?0:P"Fizz"))+(n%5?0:P"Buzz"))?:P"%d",n);P"\n");n>99?:main(n+1);}
28.
by wickberg 14y ago
A few different reasons we keep them split: - Jitter. Others have mentioned it, but I'll repeat it. These systems run carefully tuned microkernels to try to avoid any spurious interrupts, placing disk storage directly in the system would ca
29.
by wickberg 14y ago
There are a few different companies that have ARM + custom interconnect systems out there or in development. They're not necessarily cost-competitive yet, but they're an interesting start. Dell's "Project Copper" - http://content.dell.com/
30.
by wickberg 14y ago
Yes, from a performance standpoint there's no reason to go after this type of system. No one is arguing this is a good system for production work. The application of this is a teaching model. It's a lot easier to demonstrate parallelism gai

More ›