Real-World Write Performance

To make sure that I have fully tested all of the CF cards, I will run a myriad of tests. First, I will conduct basic recording tests in order to determine the impact of different CF card speeds on actually taking pictures.

Recording tests are performed with two different cameras: Canon's EOS 20D DSLR and Canon's PowerShot A95 Point-n-Shoot. For these tests I set up my studio background and lights and some different objects to create a scene. The camera was left on a tripod with its position locked tightly, and the camera aimed at the same spot for the duration of all testing to ensure continuity between file sizes. I was able to remove and replace the CF cards without moving the cameras from the tripod.

I used a stopwatch to record the time from when I pushed the shutter button until the LED on the camera stopped flashing to let me know it was done recording, and each test was done three times and the results were averaged. My hand is not mechanical so this is not a "perfect' test, but I did often re-do a run if I knew it wasn't accurate enough, so my results are at least reliable.

I shot in several different modes on each camera with all of the CF cards. For the 20D, modes included 1 Superfine JPEG, 1 RAW, 1 RAW + Superfine JPEG, Burst 6 RAW, Burst 6 RAW + Superfine JPEG. I excluded Burst Superfine JPEG testing because the # of shots taken was inconsistent, varying from 25 to 27, therefore making total file size inconsistent and therefore making the data inaccurate. For the A95, modes included 1 Superfine JPEG and Burst 13 Superfine JPEG.

File sizes for each of the Record tests in the various camera modes are shown below:

• A95 1 Superfine JPEG: 1.8 MB
• A95 Burst 13 Superfine JPEG: 23.7 MB
• 20D 1 Superfine JPEG: 3.0 MB
• 20D 1 RAW: 7.0 MB
• 20D 1 RAW + Superfine JPEG: 9.9 MB
• 20D Burst 6 RAW: 42.2 MB
• 20D Burst 6 RAW + JPEG: 61.6 MB

A95 Write Tests
(Show All Graphs) (Collapse Graphs)

A95 1 JPEG

A95 13 JPEG

SanDisk Ultra II 1GB

PNY 512MB

Kingston Elite Pro 50x 1GB

SimpleTech 1GB

ATP High Speed 60x 1GB

Lexar Professional 80x 1GB

Lexar Professional 40x 2GB

Crucial 1GB

2.4

2.4

2.6

2.6

2.6

2.6

2.7

2.9

0

seconds (lower is better)

60

 

 

A95 1 JPEG

A95 13 JPEG

PNY 512MB

SimpleTech 1GB

Kingston Elite Pro 50x 1GB

ATP High Speed 60x 1GB

Lexar Professional 80x 1GB

SanDisk Ultra II 1GB

Lexar Professional 40x 2GB

Crucial 1GB

34.4

34.7

34.8

35.1

35.5

36.1

36.9

42.9

0

seconds (lower is better)

60

 

 

Before I ran these tests I suspected that there would be no real difference in record speeds on the point-n-shoot camera. It turns out that I was a little bit right and a little bit wrong. There is a .5 second gap between the fastest and slowest card when shooting a single Superfine JPEG, but that's definitely nothing to write home about, and it is unlikely that you would even notice the difference while shooting. It is worth noting, however, that the PNY card was just as fast as the Sandisk Ultra II - strange! Shooting a 13 Superfine JPEG burst shows a difference of 8.5 seconds between the fastest and slowest card. That is a considerable difference. Notice that the PNY was the fastest in the burst test, while the Sandisk Ultra II was the slowest, this is the opposite of what I would have expected.

With the 20D, the performance is more in line with my expectations, and we start to see more variance between the cards. Shooting a single JPEG shows only a .5 second gap between the fastest and slowest cards. Like with the A95 record test, the Sandisk Ultra II is the fastest and the Crucial the slowest when shooting a single JPEG. These positions (fastest/slowest) do not change throughout the 20D record tests, with the deltas being .5, .8, 1.5, 5.1, and 7.3 seconds respectively. It isn't really until we get into the burst shots that we see much of a difference between each of the cards