Tony,

I was reading your 70-536 MCTS training book, when I saw that that you were a photographer. I find that to be strange, considering the fact that I too am a programmer who is also a photographer. At first, I found what must be your old website (http://www.northrup.org/). Upon seeing that site, I said that this guy must be joking when he says that he is a photographer. However, fortunately there is a link to what must be your new website (http://www.northrupphotography.com). The pictures on that site are incredible. Not to mention the fact that the layout is very appealing to the eye. However, as a writer of many windows books, what are you doing with a PHP website? That’s like going over to the dark side. After I finish the 70-536, it is my plan to update my site in a manner like yours, however I will utilize Microsoft Silverlight. Well, thanks for the inspiration. Take care.

My (wordy) answer after the jump.

This is an interesting study between presentation and function. Both northrup.org and northrupphotography.com are current, and all the pictures you see at northrupphotography.com are also shown at northrup.org. Northrup.org has about 15,000 additional pictures–I only show my “prettiest” work at NorthrupPhotography.com. If you’re looking for a picture of a baby ostrich (and plenty of people are, surprisingly), Google will send you to northrup.org.

NorthrupPhotography.com gets like 20 visitors a day, while northrup.org gets thousands and thousands. NorthrupPhotography.com costs me a couple of hundred dollars per year to run, while northrup.org makes a very healthy profit from selling pictures and advertising.

I also sell my pictures as stock at all the big stock photo agencies. Everyone other than stock photographers would consider them quite boring, however, because they’re meant for business use.

Re: Silverlight vs. Flash–I’ve dabbled in both, but the Flash I use on both northrup.org and NorthrupPhotography.com was written by other developers. In fact, NorthrupPhotography.com (including the PHP and Apache hosting) is a site I bought from BluDomain.com. I know my strengths and weaknesses, and creating pretty user interfaces is a weakness. So, I bought Flash components for both websites and just plug my pictures in (though everything but the slideshow interface on northrup.org uses a .NET Framework back-end that I wrote and Microsoft server software).

About 95% of my visitors have Flash installed (the rest are probably on an iPhone). I don’t even know how many visitors have Silverlight installed, because my analytics don’t track it. This site does, though, and it seems to be about half:

http://www.riastats.com/

I simply can’t use Silverlight right now because it would leave half of my users without an important component of the user interface. The SilverLight people have already made amazing progress getting it installed on half the browsers out there, and in a couple of years I’ll be able to migrate from Flash to Silverlight.

In summary, I use the .NET Framework for all my own programming, and all my client and server computers run Windows 7/Windows Server 2003/Windows Server 2008. I’m not trying to re-invent the wheel, though, and I’m happy to use pre-programmed Linux/PHP/MySQL/Flash components–as long as someone else is managing them :).

Tony

That’s a screenshot from my favorite free tool for testing hard disk performance–HD Tune (there’s a pro version you can buy, too). That’s from my Seagate Barracuda 7200 RPM 1.5 TB SATA drive backup drive.

The Blue Line–Transfer Rate

First, the blue line is the transfer rate. That’s the speed which the hard disk sends data to the computer when a big file is lined up nicely–defragmented, in other words. Notice that the line starts high (at 126 MB/sec) and drops (to about 57 MB/sec). That’s because the test moves from the outside of the drive to the inside. Disk drives are round, like a record, and so the outside spins faster (in inches/sec) from the inside.

Windows starts storing data on the outside of your disk, and works its way towards the center. That way, your files will be as fast as possible. The fact that the performance drops by 65% from the outside to the inside of the disk helps illustrate that disk performance is WAY better for files stored on the outside of the disk. It also shows one big reason why, as your disk fills up, it also slows down.

The Yellow Dots–Access Time

The yellow dots show random access time. That’s the time it takes for the disk to jump from one part of the drive to the next. In other words, that’s how long it takes to jump from the end of one file to the beginning of the next, or to jump between two segments of a fragmented file. The average access time for this disk is 13.5 ms–but lower would be better.

USB Flash Drive Performance

The previous graph shows typical performance from a hard disk, but USB flash drives behave very differently. They don’t have spinning platters–data is read by sending electrical signals. If you think they’ll be faster, you’re right. If you think they’ll be slower, you’re right.

As you can see, the transfer rate is WAY slower. My Seagate had an average transfer rate of 100 MB/sec, but my USB flash drive was at 16 MB/sec–about 6X slower. The access time is 0.8 ms, though–about 17X faster. So, USB flash drives are faster at random access and slower at sequential reads.

ReadyBoost uses this to improve the performance of Windows by caching files from the hard disk to a flash drive. If it would be faster to read it from the flash drive (like, if it’s a small segment of data that would need to be randomly accessed), it reads it from the flash drive. Otherwise, it takes advantage of the hard disks high sequential read performance.

Many new mobile computers ship with flash drives instead of conventional disk drives. In some ways, performance is better, and in other ways, performance is worse. The transfer rates of flash drives will increase over time, however, and Windows 7 includes some major improvements that speed up flash drives.

How to Get the Best Performance

I do a great deal of photo and video editing with my Canon EOS 5D Mark II–that’s 21 megapixel pictures and 1080P video–and a really fast disk makes things much more efficient. When I bought a new computer, I set it up with a very fast disk subsystem. Not the fastest in the world, mind, you, but a good bang for the buck. I chose two EXPENSIVE 15,000 RPM disks and put them in a RAID 0 array, which reads and writes to both disks at the same time. Here’s the performance I got:

Overall, that’s about twice as fast as my 1.5 TB drive (though I might have expected better…)

On Laptop Performance

So far, I’ve been discussing the disk performance of my desktop computer (a Dell Precision T3400). The main reason I bought a desktop was to get better disk performance–laptops tend to be really bad, owing to the use of small disks. Remember my lecture about how disks perform best at the outside edge of the platter? Well, smaller disks have smaller outside edges, so performance drops. Laptop disks also tend to be optimized to reduce power usage, so they spin at a slower RPM. Here’s the disk that shipped with my Dell D820:

Abysmal, right? The average transfer rate is 3X slower than the cheap Seagate drive I began this discussion with. All hope is not lost, however. It’s not too hard to upgrade a laptop hard disk–just backup to an external disk, swap drives, and then do restore to the new disk. I upgraded to a newer, faster, 500GB drive and got this performance:

The new disk doubled the average transfer rate (though the access time actually dropped a bit). It sped up the computer noticeably. So, if our laptop seems slow, upgrading the disk might be the right choice.

Got a fast or slow disk? Need some advice about hard disk performance? Tell me about it in the comments.