@dang, why is there no black bar at the top of HN?
Luiz André Barroso has died
21–27 of 27 posts
Re: Luiz André Barroso has died
#22Oh, that's a shame. Luiz was one of the nicest people I met at Google and his tech contributions were excellent. He also promoted "roofshots over moonshots", which was a philosophy badly needed.
Because I was curious and others may be too, written by the man himself: https://rework.withgoogle.com/blog/the-roofshot-manifesto/
Thanks for sharing this article.
It feels like a hopeless endeavour to learn technical skills in later stages of life, reading the article helped me believe in maintaining my focus.
Re: Luiz André Barroso has died
#23Oh, that's a shame. Luiz was one of the nicest people I met at Google and his tech contributions were excellent. He also promoted "roofshots over moonshots", which was a philosophy badly needed.
Because I was curious and others may be too, written by the man himself: https://rework.withgoogle.com/blog/the-roofshot-manifesto/
He gave "self-driving cars" as an example of "disruptive, 10X leaps in technology". I am not so sure if that what we need is even more cars on the roads.
Re: Luiz André Barroso has died
#24Oh, that's a shame. Luiz was one of the nicest people I met at Google and his tech contributions were excellent. He also promoted "roofshots over moonshots", which was a philosophy badly needed.
Because I was curious and others may be too, written by the man himself: https://rework.withgoogle.com/blog/the-roofshot-manifesto/
https://web.archive.org/web/https://rework.withgoogle.com/bl...
Seems the source is overloaded or down.
Re: Luiz André Barroso has died
#25"By customizing nearly every inch of Google’s data centers and the hardware within them, including power supplies and cooling kits" This is the second time i hear about a company building its own power supply, the first being apple for the apple 1. As i know "nothing" about electricicty, i wonder : isn't power supply a solved issue at this point ? What could have they done differently that justify having its own prod…
There isn't a lot to the Apple power-supply story. An Apple employee designed a switching power supply at a time when the industry was moving from linear to switching power supplies. Ken Shirriff writes more: https://www.righto.com/2012/02/apple-didnt-revolutionize-pow...
Yes, low-voltage power supplies are commodities. But they're also complex and critical to a product's operation (look up "glitching attacks" to see how squirrely power can influence behavior). If running hardware reliably at scale is part of your company's core competency, then your core competency will likely also include understanding the power being supplied to that hardware.
Re: Luiz André Barroso has died
#26"By customizing nearly every inch of Google’s data centers and the hardware within them, including power supplies and cooling kits" This is the second time i hear about a company building its own power supply, the first being apple for the apple 1. As i know "nothing" about electricicty, i wonder : isn't power supply a solved issue at this point ? What could have they done differently that justify having its own prod…
There isn't a lot to the Apple power-supply story. An Apple employee designed a switching power supply at a time when the industry was moving from linear to switching power supplies. Ken Shirriff writes more: https://www.righto.com/2012/02/apple-didnt-revolutionize-pow... Yes, low-voltage power supplies are commodities. But they're also complex and critical to a product's operation (look up "glitching attacks" to see…
For datacenters, there are many design decisions for the power supplies and what voltages to use. The obvious solution is to use commodity PC hardware, so you have 120 volts AC to the computer's ATX power supply, which generates 12 volts DC, which is dropped to e.g. 1.5 volts on the motherboard to power the CPU. But this isn't the most efficient approach. You're going to get more efficiency with higher AC voltage (e.g. 208 volts). And you're going to get more efficiency with higher DC voltage (e.g. 48 volts). And also ATX power supplies aren't optimized for datacenters, since they have a lot of historical baggage and voltages that may not be needed (like standby). So there is a lot that can be done to squeeze more efficiency out of the power supplies.
Here's a Google presentation about changing to a 48V architecture: https://www.opencompute.org/files/External-2018-OCP-Summit-G...
Google has also used new circuitry for the DC-DC conversion. Here's a paper on their switched tank converter to drop 48 volts to 12 volts: https://storage.googleapis.com/pub-tools-public-publication-...
Re: Luiz André Barroso has died
#27I shared an office with Luiz for 2 years - with Urs Hölze and Bart Sano - I joked with them that I got a PhD every 12 months hanging out with them. Luiz was an amazing engineer - and a great teacher, role model, philosopher and amazing friend. Rest well my friend - you made an indelible mark on me.