Wednesday, March 04, 2015

Easy 2011 iMac Memory and Hard Drive Upgrade

My iMac (2011, 21.5-inch model) was feeling down.  It was running out of disk space and everything was slowing down to a crawl.

So a few weeks ago I decided to upgrade my iMac with a larger hard drive and increased memory, restoring performance to be faster than ever.  It was far cheaper to upgrade my Mac, and it was much easier than I expected.

It took me about 30 minutes to do the upgrades.

Here are the specific parts I used for my upgrade:


Hard Drive


I went with this 4 TB Seagate drive for a few reasons:
  1. It's HUGE.  At 4 TB, it is eight times bigger than the stock 500 GB hard drive.
  2. It is affordable.  Per GB, it is far cheaper than any SSD.
  3. Being a "Hybrid" SSD/Hard drive device, it is FAST.  The modern OS really expects fast disk devices. This sped up my Mac a lot.
  4. It is a one-for-one replacement for the old device.  It easily fits inside the case.


Thermal Sensor


To upgrade the hard drive in a 2011 iMac, you need to add either a special temperature sensor or special software to make sure the fans run properly.  I went with the OWC thermal sensor hardware because it is priced somewhat similarly to a software solution, and it should be more reliable than software which can go out of date.


Memory


Memory is cheap, and the 2011 iMac has four (!) slots.  I added this inexpensive 4 GB of memory, and in doing so it brought my available RAM up to 8 GB - which is plenty for the average Mac user.  If you want to go nuts, bigger RAM chips are a possibility - according to Internet lore, you can add four 8GB SIMs to bring it to an unreasonable 32 GB.


Upgrade Instructions


For tools, all I needed was the following items
I used a few different instruction on-line to do this upgrade.  I won't repeat them blow-by-blow, but will just say that I had an easy and trouble-free time using the following directions:

iFixIt Hard Drive upgrade instructions
Excellent printable instructions for upgrading the hard drive, but doesn't cover the thermal sensor.

OWC Hard Drive upgrade video instructions
Video instructions.  Covers the 27" iMac, but it is very very similar to the 21.5"

iFixIt Memory upgrade instructions
Excellent printable instructions for upgrading the memory.

And there you have it!


Friday, October 03, 2014

iOS8 on iPhone 4S: Is it worth it?

Last week I decided to take the plunge and upgrade my household iPhone 4S's to iOS8.  The rumors on the street have been mixed, but I usually don't pay much attention to rumors because they are very often wrong.

I am very happy I upgraded.  All the fear-mongering about bad performance and bad battery life simply wasn't true for me.  I'm quite confident that those folks just had a bad app that they didn't know how to update, or a heavily-used 3 year old battery.  iOS 8 isn't going to fix your refrigerator, but it isn't going to break it either.

So what do I get?

First of all, I get a refined UI.  iOS7 was a great upgrade, but now iOS8 is simply smoother all around.  It erases all doubts I had moving from iOS6.

Family sharing is in place.  If you have a household with more than one device, this is a big deal for making Dad's life easier.  Or mine.

I get better battery management, with the incredibly useful Battery Usage feature.  Unlike the similarly named Android feature, Battery Usage fully sums up the load of your apps on the battery and gives good advice on improving battery life.  (The Android feature is just a modified top and has limited utility).

Pan-device searching with Spotlight is amped up.  New keyboards.  Notifications.  Photo and Audio filters (VERY awesome, smoothly executed, and well behaved).

So far I have yet to have a single crash of either the OS or -any- application.  ROCK SOLID.

Should you upgrade?  You certainly don't have to.  But I think you might want to.

Sunday, August 03, 2014

Excellent DD-WRT Router for Me: Netgear WNDR3400 / N600

My WiFi performance was suffering, and so I decided to do something about it and upgrade my router.

When I say my WiFi performance was suffering, I really mean it:  I live in a large high-rise apartment building and there are 100+ WiFi access points visible from my home office.  All of the contentious traffic was severely curtailing my WiFi reliability.  I was lucky to get 1 Mbit/second throughput.  Sometimes I was lucky to stay connected even with my WiFi router in the same room.

I decided it was time to go for 5 GHz, which is a WiFi band which is used less frequently and which has a tougher time traversing walls.  And of course I wanted DD-WRT support.  The set of features I was looking for included:
  • Trouble-free DD-WRT support
  • 5 GHz 802.11n Support
  • Simultaneous dual band capability
  • Inexpensive.  Maybe even cheap.  For me this means under $50.  Under $35 is even better!
It sounds like an easy task to bring all this together: All of this technology has been around for over 5 years.  But nothing is as easy as it seems until you know exactly what to do.  Finding the best router for DD-WRT takes a lot of qualitative analysis.

Finding the best router: WNDR3400 (or N600)

After doing some research I found that some Netgear WNDR3400's can be very inexpensive and  support DD-WRT.  This router is also known as the Netgear N600.  In particular, DD-WRT is compatible with version 1 of the '3400.

In shopping around, I found this refurbished Netgear WNDR3400 routers for sale on Amazon for under $35.  I figured the price was right, and if I managed to get a version 2+ I would assess it on its own merits.

Well, I ended up getting a version 2, which is not DD-WRT compatible.  But I fired it up anyway, and it performed wonderfully in terms of reliability - it sped up my home WiFi incredibly.  I decided to keep the WNDR3400v2 using the principle that "super-fast working WiFi without DD-WRT" is better than "awful WiFi".

Version 2 Label

After a month or so of operation I remained happy - the N600 was working great.  A family member gave me a call and needed a new router, so I decided to buy another WNDR-3400 for her.  After all, it provided great performance and at an incredible price.   But when I got my next refurb, it was a Version 1!  The gamble paid off!


Version 1 label
Interestingly, the physical details of the v1 is a quite a bit different than the v2.  In particular, the port layouts and LEDs are different.  Both versions purport to have identical function, but clearly they are different devices on the inside.  Anyhow, with a version 1 model in-hand I was ready and excited to install DD-WRT!
The N600: v1 on bottom, v2 on top. They must be very different on the inside.

Choosing the right DD-WRT firmware for the WNDR3400

The hardest part about DD-WRT is knowing what firmware to install.  I have a list of what I look for:
  • A version that has the features I need
    • 2.4 & 5 GHz WiFi
    • Working Ethernet
    • Working SSH
    • Working IPTables
  • No Heartbleed-ing
  • Reliable
  • Known not to brick or otherwise destroy the router
Sounds easy, right?  Never!  The DD-WRT community has an incredible amount of informal documentation, and parsing it all is a substantial job in of itself.  DD-WRT is a hobby, not a product, and so there are a lot of tradeoffs, broken features, gotchas, and potential brick-makers.

After some significant research, I chose a build that seemed to have the right mix of reliability and working features that wouldn't brick my WNDR3400.  To be precise, I used exactly this build:

ftp://ftp.dd-wrt.com/others/eko/BrainSlayer-V24-preSP2/2013/05-27-2013-r21676/broadcom_K26/dd-wrt.v24-21676_NEWD-2_K2.6_mini-WNDR3400.chk

 Installing DD-WRT on the WNDR3400

Now, before you try to do this, just remember that this worked perfectly for me but it may not work for you at all. So please proceed at your own risk. After all, some people do things like drive their car to the repair shop because the oil light is flashing red.

Once I downloaded the firmware build noted above, I installed the firmware using the following procedure:
  • Turned off my computer's wifi
  • Connected my computer to the router's port #1 via an ethernet cable.
  • Restarted the WNDR3400 via its power switch
  • Fired up Firefox on my computer
  • Entered the Netgear firmware update page on http://192.168.1.1/
  • Used the Netgear's firmware update page to install the firmware.
  • Waited about 5 minutes
After installation (again, about 5 minutes), the WNDR-3400 rebooted and the DD-WRT login page appeared.  After that, I used the DD-WRT configuration pages to set up the access point exactly how I like:
  • Set the local password
  • Set the SSID and WPA2 password
  • Configured DDNS
  • Configured SSH
  • Configured port forwarding, static DNS entries, etc.
After configuring all this I did a speed test.    Performance was as awesome - just as good as a hard-wired connection to my cable modem.

Now my WiFi is fast, reliable, and has DD-WRT.  My old v2 router will go to my family, who can use it without DD-WRT.

My WNDR3400 v1 in action with DD-WRT!
Issues with r21676

The only impactful bug I have found so far is related to SSHd.  Despite leaving the private sshd port  22 and putting the public sshd port on 10002, SSHd was publicly listening on 22 and 10002.  This is behavior is different than other DD-WRT builds I have used. 

My simple work-around was to have sshd only available on 10003.  Interestingly, I didn't immediately see this via iptables or netstat.  It took a portscan for me to reveal this.

 So far I find the WNDR3400 very reliable.  It has been up and running for more than a month without any known issues.

Installing DD-WRT on a WNDR3400v2

I have read about some people being successful installing DD-WRT on a v2, but I was unwilling to try - the evidence I saw out there wasn't that strong or compelling.  But if you try, please let me know the outcome in the comments.


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