Daniel Lemire

FEBRUARY 8, 2019

The division by a power of two ( / (2 N )) can be implemented as a right shift if we are working with unsigned integers, which compiles to single instruction: that is possible because the underlying hardware uses a base 2. Thus if 2 N / d has been precomputed, you can compute the division n/d as a multiplication and a shift. Can we do better?

C++ 279

C++ Benchmarking Hardware Testing 279

John McCalpin

FEBRUARY 17, 2025

From the form of the equation the units are GB/s * ns = Bytes, but to understand how this maps to computer hardware resources it is almost always more convenient to translate this to units of “cache lines” (with 64 Bytes per cache line in the processors reviewed here). The same is true for software prefetches.)

Latency 71

Latency Hardware Cache Systems 71

Brendan Gregg

NOVEMBER 29, 2017

Hardware virtualization for cloud computing has come a long way, improving performance using technologies such as VT-x, SR-IOV, VT-d, NVMe, and APICv. The latest AWS hypervisor, Nitro, uses everything to provide a new hardware-assisted hypervisor that is easy to use and has near bare-metal performance. I'd expect between 0.1%

Virtualization 110

Virtualization AWS Hardware Storage 110

Brendan Gregg

MARCH 16, 2024

To explain this example in more detail: The profiler periodically interrupts software execution, and for those disconnected stacks it happens to be the execution of the kernel software ("vfs*", "ext*", etc.). and we may have been flying close to the edge of hardware cache warmth, where adding a bit more instructions caused a big drop.

Java 137

Java Cache Google Hardware 137

SQL Performance

JANUARY 23, 2020

Waits and Queues has been used as a SQL Server performance tuning methodology since Tom Davidson published the above article as well as the well-known SQL Server 2005 Waits and Queues whitepaper in 2006. Since CPU and IO consumption translate directly to server hardware and cloud spend, this is significant. Most Queries Don't Wait.

Tuning 115

Tuning Servers Monitoring Hardware 115

Sutter's Mill

DECEMBER 29, 2011

Now welcome to the hardware jungle. From 1975 to 2005, our industry accomplished a phenomenal mission: In 30 years, we put a personal computer on every desk, in every home, and in every pocket. In 2005, however, mainstream computing hit a wall. The free lunch is over. Galaxy S II, Droid X2, iPhone 4S). There’s no going back.

Hardware 40

Hardware Games Operating System Software 40

The Agile Manager

MAY 31, 2022

Compare that to the relatively robust period of 2005 , when real interest rate curves were positive. Labor productivity improvement was so great compared to the hardware and software costs, interest rates had no discernible effect. In real terms, interest rates are still negative for 5 and 10 year horizons.

Hardware 52

Hardware Innovation Availability Software 52