SDE ScienceLover's blog

Weaning my Family from Windows to Linux

It started when my daughter got Leukemia (we're almost 2 years on now, and she's doing well). A cancer charity bestowed her with a Netbook computer running Windows 7 Starter. While delighted to have her own laptop computer, she often complained of "how slow" it was. Looking it over, it was clear that even the Starter edition of Windows 7 could be a drag on this resource-limited machine.

I already use Ubuntu via VirtualBox for software development and testing at my work. Therefore, my first attempt at resolving this for her was installing Ubuntu 12.04 via the Wubi installer. She liked it, but a month later was still complaining of performance issues. Sure enough, Unity was just too heavyweight for the little system to "just work nicely".

After searching around. I found Peppermint OS, an offshoot of Lubuntu that is focused on giving a Chromebook-like experience via Chromium and "desktop web apps", but without sacrificing the ability to be a general-purpose Linux computer. I installed it as a proper dual-boot option on her netbook. She loves it, and it even got a positive response from all other family members who have borrowed her machine from time to time. A few weeks ago, I provisioned a 2008-era Core 2 Duo Dell laptop for my wife with Peppermint OS as well. Total cost: $47 ($5 to take it off my workplace IT department's hands minus power supply and hard drive, $4 for a power supply, $38 for a 120 GB hard drive)

See the next post for how I'm gradually migrating our living room PC from Windows 7 to Linux as well. This one is more challenging because it's my little ones' "game machine" as well as our Netflix/Amazon Video/DVD/Blu-Ray box.

The Speed of PCI Express

PCI express if often quoted as having 500 MB/sec data transmission speed per lane. I've decided to blog the calculation, since I don't see it pulled together satisfactorily anywhere.

Gen 2

• Each "lane" of a PCI Express slot consists of a transmit path and a recieve path, each path capable of 5 Giga-transfers per second (5 GT/sec) (see https://secure.wikimedia.org/wikipedia/en/wiki/Gigatransfer for details on this unit).
• The path is 1 bit wide or 1/8 of a byte wide.
• Also, the transmission uses 8B/10B encoding, which means 10 bits are transmitted for every 8 bits of data. (See http://en.wikipedia.org/wiki/8B10B).

1/8 byte / transfer  x  5 GT/sec  x  8/10= 0.5 GB/sec = 500 MB/sec

Also remember that this data rate is each way simultaneously, since each lane has two paths for full duplex operation. That is why you sometimes see an "aggregate rate" advertised of 1000 MB/sec or 1 GB/sec.

Typical PCIe Gen 2 slot sizes  on performance machines are 1x, 2x, 4x, 8x and 16x, where the numbers refer to the number of lanes. The lanes can be used in concert to multiply the data rate.

Type	One-way Data Rate (GB/sec)	"Aggregate" Data Rate (GB/sec)
1x	0.5	1
2x	1	2
4x	2	4
8x	4	8
16x	8	16

I hope this clarifies things somewhat for somebody else out there.

Gen 3

PCI Express 3.0 is coming. The transfer rate has been increased from 5 GT/sec to 8 GT/sec, and some tricks around encoding have been pulled off. The new encoding scheme uses 128B/130B encoding. So, one way on a single lane, the data rate is as follows:

1/8 byte/transfer  x  8 GT/sec  x  128/130 = 128/130 GB/sec ~ 0.985 GB/sec ~ 985 MB/sec

So, by increasing the clock rate by 60% and the encoding efficiency by 20%, the data rate has been nearly doubled in this new generation.

SATA 2 and SATA 3

Referring simply to one-way data speeds, SATA 2 is capable of 3 GT/sec and SATA 3 of 6 GT/sec. Both use 8B/10B encoding, which gives data speeds of 0.3 and 0.6 GB/sec respectively.

Read Daniel Suarez's Novels *NOW*

Daemon

Freedom (TM)

Just read these a few months ago. Best couple of sci-fi thriller books I've seen in a while.

Ship It! -- Book Review

Ship it! A Practical Guide to Successful Software Projects

Jared Richardson

This is a fantastic book. Developers of all levels of experience can learn something from their hard-won pragmatic best-practices.

Being Prepared

Just in Case

Kathy Harrison

I used my February 15% coupon from Barnes & Noble to pick this one up. I've only just begun to read it, but I want to become serious about having reserve supplies at home in case of emergency, or simply the unexpected.

Currently Reading: Pompeii

Pompeii: A Novel

Robert Harris

I'm about a third into this. I never imagined I could be gripped by a book where most of what is going on is aqueduct engineering. It is a facinating read, though, so far. I never realized just how advanced the Romans were.

The Crisis of Credit Visualized

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The Crisis of Credit Visualized from Jonathan Jarvis on Vimeo.

Dean Koontz's Frankenstein

 

Prodigal Son (Dean Koontz's Frankenstein, Book 1)

Dean Koontz

My parents got me these for Christmas, and I ripped right through them. The final volume was apparently due in 2006, but there's nothing I can find online about it. Does anybody out there know when he will be publishing it?

 

City of Night (Dean Koontz's Frankenstein, Book 2)

Dean Koontz

Android versus iPhone...

Android versus iPhone

Apologies to Slashdot Review

Lately, I keep liking the Youtube video's Andy posts on the SlashDot Review blog, and grab them for my blog, too. Today's theft is a demo of Microsoft Sphere. I was blown away by a live demo of Surface a couple of years ago, and this is a nice evolution of that.

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Microsoft Sphere Demo