By April 8, 2009

SanDisk Extreme IV compact flash review

As soon as you hear the mention of SanDisk’s name I’m sure that memory cards will spring to mind. SanDisk are arguably the top memory card manufacturer and certainly the choice of many a professional photographer.


Here we are looking at the SanDisk Extreme IV Compact Flash card. So what’s the Extreme IV part all about? Extreme IV refers to the fact that this Compact Flash is UDMA so should be capable of up to 45MB/s transfers. 

One of the ways you’ll know that you are looking at a quality product is that it comes neatly boxed and well presented rather than in a plastic blister pack that you’d find cheaper memory cards in.


You may be wondering why speed is so important and why not simply focus on capacity? As DSLR manufacturers continue to push the boundaries with their sensors we’re starting to see even the entry level cameras with 15 megapixel sensors with the higher end going to 25+. If you add the RAW shooting capability in to the mix then you’ll find that each photo can be upwards of 17MB. That’s a fair amount of data to write to a memory card every time the shutter it released and if you add in high speed burst shooting you can start to see why memory card speed might be important. The faster the memory card the more photos can be recorded in a burst. So taking the Extreme IV for example and recording JPG images to the memory card on the Canon EOS-50D you can record in bursts continuously! Pretty important if you are photographing a lot of action.


So in order to see how much difference the UDMA technology makes to the Extreme IV I’ve compared it to another unbranded 8GB compact flash card.

In the test I wrote a series of RAW photo files to the memory card and timed the overall write speed. I performed the test several times with each card and took the average of each. I’m writing 6 RAW files to each memory card and the images are 17.1MB each.

SanDisk Extreme IV 8GB CF 6.03 seconds
Generic non-branded 8GB CF 14.94 seconds

So just simply looking at the results above you can see that the Extreme IV is more than twice as fast as the generic compact flash, this will certainly make a noticeable difference.

However, it’s not just about write speed, we should also consider read speed.

Having used the generic no-name memory card in my Canon 50D for such a long time and reading a few hundred images in from the card at a time this can take a few minutes. I’ve been using the Extreme IV for the past few weeks and it’s obvious that it’s a much faster card when it comes to downloading images, in fact I’m pretty sure that the memory card is faster than the USB connection on the camera and the card reader, so we’ll be looking at a Firewire reader soon.



Is the SanDisk Extreme IV compact flash card worth the extra money? That al depends on how much you use your camera. If you are a casual photographer then I’d say the Extreme IV isn’t going to be worth the additional cost (more than twice as expensive as a generic brand). If however you are a very keen amateur or a pro then you might want to invest in one of these. I’m sure that the time you’ll save at the end of the shoot will mean that the SanDisk Extreme IV will pay for itself in no time!


Review by: Matt

Posted in: Reviews

About the Author:

More than 20 years in the IT industry. Blogging with a passion and thirst for new technology since 2005.
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