SanDisk Extreme III 4GB SDHC


Product: SanDisk Extreme III 4GB SDHC
Provided By: SanDisk



There are a lot of devices today that use SDHC flash memory.  From GPS units to Photo Frames, and of course digital cameras, there are dozens of devices in our lives that depend on flash memory.  For many consumers, the "best" flash memory is the stuff that is on sale.  If you can find a 16GB Class 6 SDHC card for under $50, that is often considered the "best".  SanDisk has a different approach however.  While their memory comes in similar capacities, their Extreme series guarantees faster write speeds than the minimum requirement.  For instance, Class 4 SD memory guarantees 4MB/sec "transfer speed" although it doesn't say if this is read speed or write speed.  By the same standard, Class 6 SD memory guarantees 6MB/sec transfer speed.  Again, no mention of whether this is read or write speed.  In contrast, Sandisk's Extreme III series of Class 6 memory boasts speeds of up to 30MB/sec - again with a minimum transfer speed of 6MB/sec.  Today we are going to see if there is any difference between the expensive SanDisk Extreme III and run of the mill cheap flash memory.

 Box - Front
Box - Front
 Box - Back
Box - Back


About SanDisk:

Founded in 1988 by Dr. Eli Harari, an internationally recognized authority on non-volatile memory technology, SanDisk has grown to become the world's largest supplier of innovative flash memory data storage products.
Serving both consumers, (with more than 200,000 retail storefronts worldwide) and original equipment manufacturers (OEMs), SanDisk designs, develops, manufactures and markets flash storage card products for a wide variety of electronic systems and digital devices. SanDisk also licenses its technology to a number of other industry-leading companies.
With flash memory's capability for storing large amounts of data in a compact, removable format, SanDisk's products have helped drive the exponential growth in sales of digital cameras, multi-function mobile phones, USB flash drives, digital audio/video players, and other digital consumer devices.
SanDisk currently has more than 860 U.S. patents, more than 550 foreign patents, and more than 1440 patent applications pending in the U.S. SanDisk is the only company, worldwide, that has the rights to both manufacture and sell every major flash card format, including CompactFlash®, SD™, miniSD™, microSD™, MultiMediaCard™, Reduced Size MultiMediaCard (RS-MMC™ ), Memory Stick PRO™ and related Memory Stick® products, xD-Picture Card™ and USB flash drives.

SanDisk became a publicly traded company (NASDAQ:SNDK) in November 1995, and in 2007 revenues grew to $3.9 billion. With more than 3000 employees, worldwide, SanDisk is headquartered in Milpitas, California.


Bundle & First Look:

Normally there isn't much of a bundle that comes with SD cards, but SanDisk sweetens the deal with a manual, and some software on a CD.  I thought that perhaps the CD contained a catalog or some detailed specifications regarding the Extreme III card, but in fact it contains a full copy of RescuePRO.

 In The Box
In The Box
Sandisk Bundle
SanDisk Bundle


Other than a nice easy package to open, the SanDisk Extreme III 4GB card isn't much different than pretty much every other flash card on the market.  It does have a "Lock" switch so that the card is write-protected.  Take a quick peek at it if you're interested before we look at the software and start performance testing.

Sandisk Card
SanDisk Card


On the next page, we'll take a look at RescuePRO software before we jump into testing.


RescuePRO Software:

The RescuePRO software that comes bundled with the SanDisk Extreme II card is pretty handy.  It has tools to recover photos, recover videos and to recover general files.  It also provides a simple way to backup your media, wipe the media as well as a helpful, uh, help section.

Rescue Pro Running
Rescue Pro Running



The beautiful thing about RescuePRO is that it can be used on media other than flash media.  It can be used on hard drives as well as other non-SanDisk branded media.  Just make sure that when you use the "Wipe Media" that it is a flash drive and not your main hard drive.  The wipe media utility actually writes zeros to the media and after this, you cannot recover the data - even with RescuePRO.

 Rescue Pro Drives
Rescue Pro Drives

Finding and recovering data is a several step process that takes a few minutes - depending on the size of the media and the amount of deleted pictures.  The media is analyzed to find lost data, then the data is loaded in the program so you can view the deleted files - or even files off of a flash drive that has been formatted.  You can select all the files or just select individual files for recovery.  The nice thing is that you can preview the files in a larger window to make sure you are grabbing the right ones.

 Recovering Photos
Recovering Photos


The image above on the right shows the SD Card empty, yet I'm able to recover some photos.  This is very handy in the event that you accidentally delete some photos.  If you use the "Wipe Media" feature that I mentioned before, please keep in mind that you won't be able to recover any data from the card after this procedure.

As far as performance is concerned, we'll put this 4GB Extreme III Class 6 card up against some other media on the next page.


Performance Testing & Info:

As we look at performance testing, I simply used HDTach for comparison between a bunch of flash media.  We used the full read/write test on all of the media and averaged the minimum and maximum write speeds per block.  Traditionally, HDTach doesn't display all of this information, but it is available in a CSV file in the program directory.  We used multiple cards - including a 16GB MicroSD card that is a Class 4 device.

All of the cards were plugged into a Lenovo T61 laptop with an integrated card reader for best performance.  There might be faster card readers available, but for this test, all cards were tested on the same laptop.  The MicroSD card was tested in a USB-to-MicroSD adapter.

Finally before we show off individual results, we'll find out what makes the SanDisk Extreme III SD card great - according to SanDisk.

Serious professional photographers who demand one of the fastest, most rugged, and most durable memory cards on the market should choose the SanDisk Extreme III SD card. Built to work under the most challenging conditions, with SanDisk Extreme III you’ll get more speed, better performance, and unmatched reliability.

That’s because only SanDisk Extreme III memory cards feature innovative ESP Technology for the fastest speeds and highest performance. ESP stands for “Enhanced Super-Parallel Processing”. Simply put, it means you are getting the fastest read/write speeds available – an amazing minimum 20MB per second** sequential read and write speed – speed you’ll definitely appreciate whenever you find yourself shooting and storing pictures in harsh environments, extreme temperatures or at high altitudes.


For a straight one-to-one comparison, we take a 4GB OCZ 150x flash card and put it up against the SanDisk Extreme III.

HDTach - OCZ 150x
HDTach - OCZ 150x

The performance of both cards is pretty good, but the SanDisk Extreme III edges out the OCZ 150x card by a hair in the read test, and increases the lead in the write test - which is more important when it comes to DSLR usage.  Both cards manage to read back data at over 22MB/sec average, but the OCZ card drops off to 15.5MB/sec write speed while the SanDisk card bests it by 4MB/sec coming in at 19.5MB/sec.

Below is a chart that shows how all of our tested flash media compares.

Flash Performance


We tested a 2GB Eye-Fi card, a 4GB OCZ 150x SD card along with the 4GB SanDisk Extreme III card.  We also dropped in a couple of 16GB candidates - a Patriot Class 6 SDHC card as well as the 16GB SanDisk Class 4 MicroSD card.  It's interesting to see that the MicroSD card owns the Eye-Fi card in both read and write tests.  Eye-Fi has the slowest performing card of the bunch.


Final Thoughts:

At first glance the price tag of SanDisk Extreme III SD cards may turn some people off, and certainly in these tighter economic times, a cheaper card can certainly be a lot more attractive.  You must keep in mind though that these other cards are indeed "cheaper".   The price tag is lower on other cards and the quality is questionable.  I bought a new 16GB Patriot Class 6 SDHC card to take to CES and the second day out my card corrupted and I had to swap in a smaller card.  I've also had compatibility issues with some cameras and the OCZ 4GB 150x card, as it is has the capacity of an SDHC card, but in fact is not a "HC" card - only and "SD".  I have had no issues with the SanDisk Extreme III card and the performance is second to none.  Combine that with handy RescuePRO software - which retails for $40 and you've suddenly bought yourself a ~$15 card which isn't too bad at all.

Apples-to-apples, SanDisk wins based on performance and features.  However, if you're on a tight budget and don't need or want the handy RescuePRO software, you'll probably be much happier saving your money and grabbing an $11 4GB Patriot Card - just pray that it doesn't corrupt - or you'll want the software.



  • Comes with bundled RescuePRO Software
  • Fast read/write speeds



  • Couldn't hit 30MB/sec
  • More expensive than competition



 Editor's Choice

While the 4GB SanDisk Extreme III earns our Editor's Choice award, they could still make the bundle better by including a USB-to-SDHC reader for those that have a slower reader or have a laptop without a media card slot.  This would increase the value of the bundle.

I'd like to thanks SanDisk for sending this card our way for a review.  If you have any questions or comments, please post them at the "Comments" link below.