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@hellerbarde
hellerbarde / latency.markdown
Created May 31, 2012 13:16 — forked from jboner/latency.txt
Latency numbers every programmer should know

Latency numbers every programmer should know

L1 cache reference ......................... 0.5 ns
Branch mispredict ............................ 5 ns
L2 cache reference ........................... 7 ns
Mutex lock/unlock ........................... 25 ns
Main memory reference ...................... 100 ns             
Compress 1K bytes with Zippy ............. 3,000 ns  =   3 µs
Send 2K bytes over 1 Gbps network ....... 20,000 ns  =  20 µs
SSD random read ........................ 150,000 ns  = 150 µs

Read 1 MB sequentially from memory ..... 250,000 ns = 250 µs

@jimbojsb
jimbojsb / gist:1630790
Created January 18, 2012 03:52
Code highlighting for Keynote presentations

Step 0:

Get Homebrew installed on your mac if you don't already have it

Step 1:

Install highlight. "brew install highlight". (This brings down Lua and Boost as well)

Step 2:

@thijsc
thijsc / gist:1391107
Created November 24, 2011 11:08
Select item from chosen js select with Capybara and Selenium
def select_from_chosen(item_text, options)
field = find_field(options[:from])
option_value = page.evaluate_script("$(\"##{field[:id]} option:contains('#{item_text}')\").val()")
page.execute_script("$('##{field[:id]}').val('#{option_value}')")
end
@stevenharman
stevenharman / constant_scopes.rb
Created September 12, 2011 15:29
Constant scoping weirdness in Ruby...
module Foo
end
module Foo::Bar
end
class Baz
end
class Quux