| Latency Comparison Numbers (~2012) | |
| ---------------------------------- | |
| L1 cache reference 0.5 ns | |
| Branch mispredict 5 ns | |
| L2 cache reference 7 ns 14x L1 cache | |
| Mutex lock/unlock 25 ns | |
| Main memory reference 100 ns 20x L2 cache, 200x L1 cache | |
| Compress 1K bytes with Zippy 3,000 ns 3 us | |
| Send 1K bytes over 1 Gbps network 10,000 ns 10 us | |
| Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD |
FWIW: I (@rondy) am not the creator of the content shared here, which is an excerpt from Edmond Lau's book. I simply copied and pasted it from another location and saved it as a personal note, before it gained popularity on news.ycombinator.com. Unfortunately, I cannot recall the exact origin of the original source, nor was I able to find the author's name, so I am can't provide the appropriate credits.
| package main | |
| import ( | |
| "context" | |
| "flag" | |
| "fmt" | |
| "log" | |
| "net/http" | |
| "os" | |
| "os/signal" |
This is a short post that explains how to write a high-performance matrix multiplication program on modern processors. In this tutorial I will use a single core of the Skylake-client CPU with AVX2, but the principles in this post also apply to other processors with different instruction sets (such as AVX512).
Matrix multiplication is a mathematical operation that defines the product of
This week NN Group released a video by Jakob Nielsen in which he attempts to help designers deal with the problem of customers being resistant to their new site/product redesign. The argument goes thusly:
There's slightly more to it than that, he caveats his argument with requiring you to have of course followed their best practices on product design, and allows for a period of customers being able to elect to continue to use the old site, although he says this is obviously only a temporary solution as you don't want to support both.
