April 20th, 2010

Welcome to my new Blog Home

RSS icon RSS Category: Personal
Fallback Featured Image

Welcome to my new Blog Home!

And for those of you who made it, this quick tidbit.
Everybody in the JVM business optimizes for long arraycopys/memcpy.
You can get peak bandwidth on machines with a decently long memcpy.
It’s easy enough to do and arraycopy and memcpy are called a lot.
But what about short arraycopies?  How often do we call System.arraycopy with small numbers?
In a run of JBB2000 (yah, the old one – I happen to have numbers handy for it), how many times a second is System.arraycopy called?  Yes, the answer obviously depends on your score.  Lets assume your score is middlin’-high – say 1,000,000 BOPs/sec.
Did you guess 30million times/sec?  That’s 30 calls to System.arraycopy per BOP on average.
Now, how many bytes are moved on average?   – 42.5
That’s less than an x86 cache-line.
Getting a good score on JBB (and on many many benchmarks) depends on getting the overhead of short arraycopies reduced as much as possible.  Yes, in the end you need to do well on the rare 1Megabyte array copy… but it’s more important to copy those first few bytes with as little overhead as possible.
PS – We’re working on the RSS feed

Leave a Reply

AI-Driven Predictive Maintenance with H2O Hybrid Cloud

According to a study conducted by Wall Street Journal, unplanned downtime costs industrial manufacturers an

August 2, 2021 - by Parul Pandey
What are we buying today?

Note: this is a guest blog post by Shrinidhi Narasimhan. It’s 2021 and recommendation engines are

July 5, 2021 - by Rohan Rao
The Emergence of Automated Machine Learning in Industry

This post was originally published by K-Tech, Centre of Excellence for Data Science and AI,

June 30, 2021 - by Parul Pandey
What does it take to win a Kaggle competition? Let’s hear it from the winner himself.

In this series of interviews, I present the stories of established Data Scientists and Kaggle

June 14, 2021 - by Parul Pandey
Snowflake on H2O.ai
H2O Integrates with Snowflake Snowpark/Java UDFs: How to better leverage the Snowflake Data Marketplace and deploy In-Database

One of the goals of machine learning is to find unknown predictive features, even hidden

June 9, 2021 - by Eric Gudgion
Getting the best out of H2O.ai’s academic program

“H2O.ai provides impressively scalable implementations of many of the important machine learning tools in a

May 19, 2021 - by Ana Visneski and Jo-Fai Chow

Start your 14-day free trial today