Discovering Cryptocurrencies

I recently found myself in the market for a mid-range graphics card and latched onto a previously-opened (hence discounted) GeForce GTX 750 Ti from Newegg. (I purchase all my computer equipment from them. They hate patent trolls, as do I. Unlike me, they actually do something about them.)

The GTX 750 Ti is based on the new Maxwell architecture and per online reviews actually vastly improves on previous generations in terms of cryptocurrency hashing power and efficiency, traditionally the realm of ATI graphics cards. Why? Besides generally having more ALUs, ATI chips implement the important right-rotate operation in silicon, whereas NVIDIA chips don’t. Right-rotate is used extensively in Bitcoin’s proof-of-work function, SHA-256, and by extension in scrypt and scrypt-N, leveraged by alternative coins such as Litecoin and Vertcoin. That means when an ATI chip goes to right-rotate by 6, it takes one clock-cycle to complete:

01100101100101001101111001110001 rot 6
= 11000101100101100101001101111001

Meanwhile, most NVIDIA chips have to do two shifts and an addition – three clock cycles:

01100101100101001101111001110001 >> 6
= 00000001100101100101001101111001

01100101100101001101111001110001 < < (32-6) = 11000100000000000000000000000000

OR of previous two operations
= 11000101100101100101001101111001

While the GTX 750 Ti probably still doesn’t outperform a similarly-priced ATI card, it at least remedies that right-rotation penalty. I get about 250-260 khash/s out of it when doing scrypt-2048.

Continue reading Discovering Cryptocurrencies

Linux Mint 16 Install With LUKS on LVM

Fedora has been my go-to Linux distribution since before it was Fedora, way back when there simply was Red Hat Linux. I was always happy with it, but in the past few years, I’ve had less time to deal with its quirks and bugs (Fedora is, by design, more bleeding-edge and less stable than RHEL), and after the Gnome-pocalypse hit, to deal with KDE, which just wasn’t my speed.

Searching for alternative distributions, I found Linux Mint and Cinnamon – a new desktop using GTK+3. Ten minutes after running a live-DVD, I was sold, and it was time to wipe the slate clean and set up my new system. And while I don’t normally wear a tin-foil hat I did want to encrypt my new system, which led me to do a lot of reading and learning about some twists and gotcha’s, which I am documenting here in the hope they can be useful to someone else.

Continue reading Linux Mint 16 Install With LUKS on LVM


This is a small tech blog with ramblings, musings and notes on various projects I am tinkering with at any time. Less big-picture and more nitty-gritty, I hope that some of its content can be helpful to anyone trying to understand the same minutae of the complicated technology we use nowadays, without having to waste the time I did.