jeffbee

39 ms·

661.
by jeffbee 7mo ago
California has high volumetric rates, but mostly that is because it has much more distributed generation than any other state, uses far less grid power, so the grid rates are dominated by fixed grid costs. Actual monthly electric bills in C
662.
by jeffbee 7mo ago
"That costs ~5 ns when the line is cold" I don't see how that could possibly be true. Sounds like a low-ball estimate. Also i wish to point out that the "tcmalloc" being used as a baseline in these performance claim
663.
by jeffbee 7mo ago
The easy speedup is to use 2 mutexes, one that protects head and tail_cached, and the other that protects tail and head_cached, and align so they don't interfere. In other words, take the RingBufferV5 from the article and define the cl
664.
by jeffbee 7mo ago
The GNU libstdc++ STL mutex is nothing but pthread_lock, so that's not a surprise. I really don't understand what you are saying about not using custom primitives. The whole article is "YOLO your own synchronization" and
665.
by jeffbee 7mo ago
I keep an eye on jaq, but there are some holes in the story. jaq 3.0 is faster than Linux distro builds of jq, but jq built correctly is faster than jaq. As far as I can tell the performance reputation of jq is caused by bad distro packag
666.
by jeffbee 7mo ago
My point is that the "huge win" is expressed in terms of a bogus and misleading baseline. The article moves immediately from the worst possible lock-based implementation to a pretty bad atomics-based implementation. The final punc
667.
by jeffbee 7mo ago
I use jq to grind through gigabytes of GeoJSON files exported from ArcGIS, as an ETL stage. It takes a long time.
668.
by jeffbee 7mo ago
I guess A/V pros are used to getting screwed constantly, but it must be really irritating to face the prospect of eventually having to move PCI add-in cards to TB5 enclosures that cost $1000 per slot.
669.
by jeffbee 7mo ago
That only explains the last stage. In order to steelman the mutex alternative, everything before "further optimization" should have used 2 critical sections. That would give a realistic baseline.
670.
by jeffbee 7mo ago
It's lock-free because it uses ordered loads and stores, which is also how you implement locks. I find the semantic distinction unconvincing. The post is really about how slow the default STL mutex implementation is.
671.
by jeffbee 7mo ago
I don't know but the IBM 360 and the DEC PDP-10 both had them. Those are the earliest systems I ever saw.
672.
by jeffbee 7mo ago
There are some microarchitectural resources that are either statically divided between running threads, or "cooperatively" fought over, and if you don't need to hide cache miss latency, which is the only thing hyperthreading
673.
by jeffbee 7mo ago
They must be doing something that integrates user-contributed data because one quirk of their course planner[1] is an out-and-back plan along the same course will have non-coincident elevation profiles, even along trails where it can&#x27
674.
by jeffbee 7mo ago
Garmin and Strava must be sitting on a gold mine of practical DEM data based on ride and hike records. They have huge databases from mobile devices recording GPS position, speed, and pressure.
675.
by jeffbee 7mo ago
It looks pretty odd in Oakland, California, where the elevated freeways pass through the city. I guess the DEM they are using for that place is based partially on aerial radar surveys, partially on ground surveys? That's my guess based
676.
by jeffbee 7mo ago
The difference is largely in the way that the legal caste perceives themselves to be aligned with media but opposed to tech.
677.
by jeffbee 7mo ago
You mean it's the first of many appeals, I assume. Trial courts will decide pretty much anything. Then the case gets appealed over whether the trial court correctly interpreted things you probably perceive as uncomplicated, like the 1s
678.
by jeffbee 7mo ago
I am surprised that they are surprised that car wiring diagrams are online. People wouldn't accept cars without online service manuals and schematics, and some states mandate them by law. I just looked up this subsystem for my car via
679.
by jeffbee 7mo ago
Closing bugs because of a rewrite is probably the most harmful practice in the whole industry. The accumulated unresolved issues of your existing code base are a rich resource of test cases. Writing the new code base without checking to see
680.
by jeffbee 7mo ago
Closing bugs because they can no longer be reproduced: obviously fine. Closing bugs automatically after a cron job demanded that the user verify reproducibility for the 11th time: obviously bad.
681.
by jeffbee 7mo ago
It's very common but it's still a poor practice.
682.
by jeffbee 7mo ago
Yeah there are so many reasons this could be reversed on appeal. Whether the judge correctly held questions of section 230, and the First Amendment, is not obvious.
683.
by jeffbee 7mo ago
It is weird to me how far from the state of the art mainstream server equipment is. I can't imagine anything worse than AC-AC UPS, active PDUs, and redundant AC-DC supplies in each rack unit, but that's still how people are doing
684.
by jeffbee 7mo ago
It's obviously not new. ±400VDC architecture was presented at Open Compute last year, which is a fair indicator that the presenter had put it into practice at least 5 years prior to disclosing it. 48VDC distribution within a rack, and
685.
by jeffbee 7mo ago
It isn't obvious to me that they intended to give this as the maximum single-core performance, or just the proportional share of 844GB/s across 136 cores. Implementations of Neoverse V2 by Nvidia and Amazon hit 20-30GB/s in s
686.
by jeffbee 7mo ago
How much, what kind, and what is your source? All mainstream server CPUs have a megabyte or two of SRAM on a core, of course.
687.
by jeffbee 7mo ago
Many of these words are unexplained. "Memory and I/O on the same die". Oh? What does this mean? All of the DRAM in the photo/render is still on sticks. Do they mean the memory controller ? Or is there an embedded DRAM c
688.
by jeffbee 7mo ago
None of the institutions function, or do the thing that we used to explain to children what they do. The whole thing demonstrably does not exist. You're welcome to describe my view with whatever pejorative you prefer.
689.
by jeffbee 7mo ago
Thanks! I'll keep an eye out for the paper.
690.
by jeffbee 7mo ago
We didn't even get the show trial!

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