| In early November, 2012, Apple issued a graphics update for all mid-2012 MacBooks. In a continued streak of stupidity, however, this update forces your Mac to use "Safe Sleep". This means that the entire contents of your RAM is written to your disk every time you put your Mac to sleep. | |
| This is retarded on the scale of the Titanic's navigational plan for two reasons: | |
| 1) Your Mac likely has 8 or 16GB of RAM. This is a ton of wasted disk space; especially on MacBook Airs that ship with only 256GB SSDs to begin with. | |
| 2) SSDs wear out as you write to them. Each cell of a SSD can only be written to a certain number of times before it becomes read-only. If you put your computer to sleep many times a day, OS X is slowly but surely destroying your SSD with unneeded write cycles. | |
| Worst of all, the graphics update makes it IMPOSSIBLE to turn off safe sleep using the standard approach you'll find on Google: |
| ;; Big thanks to Christophe Grand - https://groups.google.com/d/msg/clojure/L1GiqSyQVVg/m-WJogaqU8sJ | |
| (defn scaffold [iface] | |
| (doseq [[iface methods] (->> iface .getMethods | |
| (map #(vector (.getName (.getDeclaringClass %)) | |
| (symbol (.getName %)) | |
| (count (.getParameterTypes %)))) | |
| (group-by first))] | |
| (println (str " " iface)) | |
| (doseq [[_ name argcount] methods] | |
| (println |
Locate the section for your github remote in the .git/config file. It looks like this:
[remote "origin"]
fetch = +refs/heads/*:refs/remotes/origin/*
url = [email protected]:joyent/node.git
Now add the line fetch = +refs/pull/*/head:refs/remotes/origin/pr/* to this section. Obviously, change the github url to match your project's URL. It ends up looking like this:
| Latency Comparison Numbers (~2012) | |
| ---------------------------------- | |
| L1 cache reference 0.5 ns | |
| Branch mispredict 5 ns | |
| L2 cache reference 7 ns 14x L1 cache | |
| Mutex lock/unlock 25 ns | |
| Main memory reference 100 ns 20x L2 cache, 200x L1 cache | |
| Compress 1K bytes with Zippy 3,000 ns 3 us | |
| Send 1K bytes over 1 Gbps network 10,000 ns 10 us | |
| Read 4K randomly from SSD* 150,000 ns 150 us ~1GB/sec SSD |
| ;; Builds of Datomic with revision numbers higher than 0.1.3057 have | |
| ;; support for :db.type/fn, :db.type/bytes, and :db/fn. | |
| ;; To add these types to a database created using with a pre-0.1.3057 | |
| ;; build, simply run the database with a newer version of Datomic, and | |
| ;; execute the two transactions below. | |
| [{:db/id #db/id [:db.part/db] | |
| :db/ident :db.type/bytes | |
| :fressian/tag :bytes |