BrendanLong

7 ms·

1.
Vibe Coding Is a System Design Interview(brendanlong.com)
2 points by BrendanLong 2mo ago|0 comments
2.
by BrendanLong 1y ago
Here's results of the Nginx benchmark pinned to 1-24 cores: https://docs.google.com/spreadsheets/d/1d_OK_ckLT1zTA_fG4vkq... At 51% reported CPU utilization, it's doing about 80% of the maximum requests p
3.
by BrendanLong 1y ago
I'd love to explain, but you'd need to change your name to Brendan first.
4.
by BrendanLong 1y ago
Fun data point though, I just ran three data points of the Phoronix nginx benchmark and got these results: - Pinned to 6 cores: 28k QPS - Pinned to 12 cores: 56k QPS - All 24 cores: 62k QPS I'm not sure how this applies to realistic wo
5.
by BrendanLong 1y ago
Yeah, the obvious thing with processors is to do something similar: (1) Measure MIPS with perf (2) Compare that to max MIPS for your processor Unfortunately, MIPS is too vague since the amount of work done depends on the instruction, and th
6.
by BrendanLong 1y ago
The advantage of stress-ng is that it's easy to make it run with specific CPU utilization numbers. The tests where I run some number of workers at 100% utilization are interesting since they give such perfect graphs, but I think the ve
7.
by BrendanLong 1y ago
Some esoteric methods of measuring CPU utilizations are to calculate either the current power usage over the max available power, or the current temperature over the max operating temperature. Unfortunately these are typically even more non
8.
by BrendanLong 1y ago
Thanks for the feedback. I think you're right, so I changed a bunch of references and updated the description of the processor to 12 core / 24 thread. In some cases, I still think "cores" is the right terminology though
9.
by BrendanLong 1y ago
A big part of this is that CPU utilization metrics are frequently averaged over a long period of time (like a minute), but if your SLO is 100 ms, what you care about is whether there's any ~100 ms period where CPU utilization is at 100
10.
by BrendanLong 1y ago
To be fair, in most of these tests hyperthreading did provide a significant benefit (in the general CPU stress test, the hyperthreads increased performance by ~66%). It's just confusing that utilization metrics treat hyperthread usage
11.
%CPU utilization is a lie(brendanlong.com)
437 points by BrendanLong 1y ago|168 comments
12.
by BrendanLong 5y ago
Expanding on that last point, one of the examples in the article is someone making ~$70 per month in cryptocurrency. The CI people -could- send a lawyer to Vietnam to try to collect that $70 but even if they succeed it's very not worth
13.
by BrendanLong 5y ago
They're not starting a CI job per hash (that would be too slow). I'm not sure exactly how each of these cryptocurrencies works, but presumably what they're doing is starting a miner which attempts hashes for a while and then
14.
by BrendanLong 6y ago
Investment info sites seem to be skeptical that there's anything wrong with naked shorts. They became illegal after the 2008 crisis, but they're bad in the sense of being extremely risky, not that they're fraudulent. It'
15.
Videos as images in HTML(brendanlong.com)
2 points by BrendanLong 9y ago|0 comments