Linux SMT-Aware Process Scheduling

Process scheduling for multicore multithreaded (SMT or HT) systems adds a new challenge to an operating system’s process scheduler. Two threads scheduled on different cores will run faster than two threads scheduled onto different thread contexts of the same core because much of the hardware resources are shared between SMT thread contexts. This can be . . . → Read More: Linux SMT-Aware Process Scheduling

PSU Fan Control

The Sparkle Power SPI270LE Flex ATX power supply has a rather noisy 40 mm fan that that is temperature-controlled to reduce noise when cool. The fan control circuit failed and powered the fan at full speed regardless of temperature. . . . → Read More: PSU Fan Control

Refrigerator Power Efficiency

It has been claimed that new refrigerators use much less power than old ones. This is also the premise of The Great Refrigerator Roundup program that encourages replacement of refrigerators older than 15 years. Here is one comparison, measured over about 3 days. . . . → Read More: Refrigerator Power Efficiency

Seasonal Fuel Efficiency

It is well-known that a car’s fuel efficiency decreases during the winter months. There are many potential contributors, including increased air density causing drag, excessively rich fuel mixture from cold starts taking a long time to warm up, increased pumping losses from dense cold air intake, increased engine oil viscosity, increased rolling friction from colder . . . → Read More: Seasonal Fuel Efficiency

Core 2, Nehalem, FPGA CAD

See also: Ivy Bridge Benchmarks

Here are some FPGA CAD benchmarks across a few relatively-modern machines. The original motivation was to figure out why VPR ran much slower on a Core 2 Xeon 5160 system than a desktop-class Core 2 Quad Q9550. A secondary goal is to measure the Core i7-980X @ 4215 MHz. I . . . → Read More: Core 2, Nehalem, FPGA CAD

Cardboard Boxes

Seeing as Engadget can get away with posting old news about computers in cardboard boxes, I will too 🙂
. . . → Read More: Cardboard Boxes

Teksavvy IPv6

Teksavvy now has a beta of IPv6 service over DSL. This is my configuration for a linux system serving as a router for a LAN. . . . → Read More: Teksavvy IPv6

USB Port Repair

The USB port on my laptop was broken by dropping the laptop onto something plugged into the USB port. It has been repaired by transplanting the core from a donor USB connector. . . . → Read More: USB Port Repair

Recording Equipment

Behringer C-2 ($65), Tascam US-122MkII ($90), laptop, piano.

. . . → Read More: Recording Equipment

Spam

Spam is profitable. With sufficient advertising by email, there will be some people who respond and generate revenue. Push the conversion rate lower still, and spam may become unprofitable. . . . → Read More: Spam