Month: April 2009

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Swine Flu on Google Maps

There is now a Swine Flu Google Map at http://swinemap.org. Black indicates confirmed deaths from H1N1. Grey are unconfirmed deaths. Red are confirmed infections. Pink are probable infections. Blue are influenza-like illnesses. As of this writing, North Dakota looks like a good place to set up your post-apocalyptic compound while you develop an anti-swine flu serum.


View 2009 H1N1 Flu Outbreak Map in a larger map

Follow CDC recommendations and thoroughly gargle after kissing any pigs that have not yet been tested. Ok, their real information is at:
http://www.cdc.gov/swineflu/

UPDATE: This post has been updated with a new Google Map that has more information.

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Cheap WiFi Antenna Boost

We recently setup a wireless antenna and bridge for a customer in Occoquan, Virginia that needed WiFi to be transmitted across a large building and through floors. While the setup worked, the signal was poor. This caused lows speeds and even occasional lost connections. Therefore we setup a cheap directional antenna to point the signal directly where it needed to go. This fixed the problem by increasing the signal strength by about 40%.

How To Build The Antenna

Go to freeantennas.com’s Ez-12 page to download the image at the bottom of the page. Then resize the image as needed, print it, use business-card strength paper, glue on the aluminum foil, and put it together. Patrick Norton explains this simple project on his old DL.tv show.

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Mac Software Striping RAID Performance

The Mac OS includes software RAID options.  Using the striping option, you can double your storage and greatly improve your read/write performance.  But what is the true performance gain and is it worth doing?

Mac Pro

What you need

First, you need a Mac capable of holding at least 2 drives.  This is actually a problem for most Macs.  Only the Mac Pro is capable of that off the shelf.  The Mac Mini can be hacked to do so but it involves removing the DVD drive and soldering in a 2nd hard drive.  The system I used in this test is the latest entry-level Mac Pro from early 2009.

Second, you need another hard drive.  The Mac Pro can actually hold 4 but for the purposes of this test, I’m only adding 1. This Mac Pro comes with a 640GB Western Digital Caviar Blue so I purchased another identical to that.  It is best to have 2 identical drives when doing striping so that both drives can be fully used.  If you’re looking for Mac Mini drives, we recommend the 500GB Western Digital Scorpio Blue.

Backup original drive

In order to add the 2nd drive, you’ll need to fully backup your first drive so that you can restore it later.  When creating a RAID setup, the drives will be wiped clean.  If you already have a time machine backup, you can do a restore from that but I prefer using Disk Utility to do a backup and restore because it can create a fully bootable 100% identical backup that you can then restore from Disk Utility off of a Leopard boot disc.  Disk Utility doesn’t word things very well.  Both a backup and a restore are both under the Restore tab.  When you backup, you just do a restore from your Macintosh HD to your external backup drive.  If you want the backup to be bootable, be sure it is partitioned with a GUID Partition Table scheme under Options.

Add the drive

Now that your data is backed up, you can add your new drive.  In the Mac Pro, this is the quickest and easiest hard drive addition ever.  Simply unlatch the drive holders and slide one out.  There are 4 screws already in there waiting to go into the new drive.  Then you just slide in the new drive and that’s it.  If you’re using a Mac Mini, you’ll need to follow this Mac Mini upgrade guide.

Mac RAID

Create the RAID
Boot up the mac off of a Leopard disc by holding down C.  Choose your language and then you’ll be able to launch Disk Utility from the top menu.  Select one of the drives and go to the RAID tab.  Enter the RAID Set Name to be the standard drive name Macintosh HD.  Then drag both of your drives to the RAID set window.  Both will show up and show the combined storage based on your RAID type.  Mirroring is for a duplicate backup.  Striping is for performance and extra storage.  You can select Create to create the software RAID and it shouldn’t take more than a few minutes.

Restore

If you did a time machine backup, you can go through the standard Leopard install and choose restore from time machine.  If you did a disk utility backup, select your new Macintosh HD volume and go to the Restore tab.  Choose your external backup drive as your source and the Macintosh HD as the destination.  If you have a lot of data, this can take several hours.  If all went well, your system should now be able to boot off your new striping RAID Macintosh HD volume.

Performance

Now that we’ve got our striping RAID, how does it perform?  Using the Xbench disk test, the drive performance has gone from a score of 73 to 112.  That’s about a 53% improvement overall.  The test uses a variety of disk usage and this striping will perform differently based on exactly how the data is being used.  The biggest benefit will be for large files.  For example, if you use a virtual machine like VMware Fusion, the virtual RAM is written and read to the hard drive when you do a suspend or resume of the OS.  The result is that with a striping RAID volume, this feels about twice as fast. Striping also combines the drives so you double the capacity.

The down side

The biggest negative is that with 2 drives required to be working, we’ve doubled the likelihood of the Macintosh HD volume failing.  If just 1 drive breaks, the whole volume is lost.  Fortunately, Apple provides time machine which gives us a reliable and effortless backup.  If you do lose a drive, you’ll need to replace the bad drive and restart the RAID set from scratch and restore.  Another downside is that because this is a software RAID, it does use a little CPU which hardware RAID would not.  But a Mac Pro hardware RAID card will set you back $700 and the CPU usage is so small, I can’t even notice it when looking at Activity Monitor.

Conclusion

If you want to massively improve your disk performance, adding a second drive and creating a striping RAID set is a great choice.  This is easy in a Mac Pro but can be done on a Mac Mini with some work.  Just be sure you always have a time machine backup running in case your RAID fails.

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2009 Mac Desktop Benchmarks

The latest versions of the Mac Mini, iMac, and Mac Pro all show improvements over previous versions.  Besides a few changes in connections, physically they are relatively unchanged.  The main improvement is in performance.

With the upcoming release of the next Mac operating system, Snow Leopard, the threading performance of your Mac hardware is now more important than ever.  Snow Leopard will be more optimized for multi-threading than any of its predecessors.  The latest Mac desktops will benefit more than previous models since they outperform significantly on thread benchmarks.

The following benchmark scores were collected by the popular Xbench Mac benchmarking software.  The new desktops are all of the entry level models. For all tests, a higher score is better.

Model Thread Test UI Test Memory Test
2006 iMac Core 2 Duo 2GHz 171 257 133
2009 Mac Mini Core 2 Duo 2GHz 231 258 162
2009 iMac Core 2 Duo 2.66GHz 360 379 177
2009 Mac Pro Xeon 3500 2.66GHz 543 409 374

It should be no surprise that the Mac Pro performs the best.  The Mac Mini has always been underpowered but at least it still outperforms some previous iMac models with similar CPU.  The entry-level iMac for $1,199 posts extremely impressive results.  For half the price of a Mac Pro, the thread performance was still great.  However, the Mac Pro truly dominates in the memory test.  The newer nehalem architecture uses tri-channel RAM which is significantly faster.  Any memory intensive applications will see a big improvement on a Mac Pro.  The iMac and Mac Mini won’t use nehalem until the end of 2009 at the earliest.

It is hard to highly recommend the Mac Mini just because it feels like it should come with a faster than 2GHz processor.  For the first time though, you can hook up 2 monitors to the Mac Mini.  The iMac offers the best value by far.  It performs great and isn’t overly expensive.  If you want the best performance and money is no object, the Mac Pro is for you.  Once Snow Leopard comes out, the performance of these new Macs should increase significantly.

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Analog versus Digital Sound

When we setup home theaters, we still get asked about the differences between analog sound, such as that from vinyl records, and digital sound, such as that from CDs. While most people are perfectly content with CDs given budget limitations and poor listening environments, analog vinyls will still produce the best sound if you use the most expensive high-end equipment.

michaelfremerSimilar discussions occur when comparing solid-state amps with tube amps, and when comparing digital synthesizers and samplers with analog synthesizers.

With the advent of SACDs, even extreme audiophiles can not distinguish between digital samples and the analog vinyl versions of songs. Similarly, modern digital synthesizers such as the Nord Lead are now considered indistinguishable from true analog synthesizers by most musicians.

Gizmodo has an article about audiophile Michael Fremer and the subject of digital versus analog. Their main point is that while most people shouldn’t spend hundreds of thousands on a music theater, it is important that some people are obsessed with having the best listening experience.

After hearing I’m a Bowie fan, Fremer drops into his near limitless stacks and spins a pressing of “Heroes” with part of the title track’s chorus in German. I’m giggling with pleasure at the frankly obscene level of detail I hear (Ich! Ich werde König!), but of course, I’m hearing the pops and crackles that a 30+ year-old record is likely to have. Shouldn’t a $350,000 stereo system be completely free of such impurities?

“It’s like when you go to the symphony, and the old men are coughing-same thing,” Fremer says. Necessary impurities. Reminders of being in the real world.

This 1993 news story from MTV featuring Michael Fremer is still applicable today: