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5th August 2006
SanDisk Extreme IV compact flash and Firewire 800 card reader review
by Ian Burley

In this review we test SanDisk's Extreme IV cutting edge compact flash and Firewire 800 combo


We think the Extreme Firewire card reader is a star in its own right.

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Pricing and availability table.
Read the official SanDisk press release.

SanDisk has just shipped us their brand new Extreme IV compact flash memory card and Extreme Firewire 800 card reader. We've not only been putting the supplied Extreme IV card through its paces, but also the card reader, which is a bit of a star performer in its own right. And we have compared Extreme IV compact flash performance with 'earlier' generation high-speed compact flash cards too.

What is new about SanDisk's Extreme IV technology?
The industry has made several performance steps in flash memory semiconductor technology recently and this has moved the performance bottleneck down the pipeline. In other words, premium flash memory has, until now, been able to operate faster than the memory controllers and data transfer environments have allowed.

Cards claiming 20MB/second performance have been available for 18 months, but few card readers or cameras have been able to fully exploit that limit. Extreme IV features the latest in flash memory controller systems, using improved parallel processing to perform the task of getting data into and out of the flash memory cells. Parallel processing lets the controller move several data bytes in one operation and just like your supermarket opening extra checkouts on a busy Saturday morning, the queues can move noticeably faster.


With Extreme IV SanDisk now claims a 40MB/sec transfer rate, or 266x performance.

Firewire 800
But it's all very well if you can do your shopping and get to your car in the car park more quickly, but no good if there is a traffic jam at the car park exit. This is where the SanDisk Extreme FireWire 800 compatible card reader makes its mark. SanDisk's Extreme FireWire Reader is IEEE1394b (Firewire 800) compliant and needs a matching cable. Luckily the SanDisk Extreme FireWire Reader is backwards compatible and both a 1394b-1394b and 1394b-standard Firewire cable are supplied in the box. IEEE1394b-equipped computers are still relatively rare, but you can upgrade a PC using an IEEE1394b Firewire 800 interface card.


That's a Firewire 800 connector on the back

FireWire 800 is, as its name suggests, theoretically capable of 800MB/sec transfer rates. SanDisk only claims 40MB/sec maximum sustained transfer rate for Extreme IV cards, but the number '800' is a bit of a red herring. What FireWire 800 offers is lower protocol latency so there is less time for the reader waiting around for the next bunch of data to be transferred.

SanDisk also offers a USB 2.0 High-Speed Extreme Reader. Even with much slower compact flash cards, I have noticed that FireWire card readers extract marginally more performance from a compact flash card and the likelihood is that the difference will be even greater – after all SanDisk wanted me to test the Firewire solution first!

All this impressive theory is one thing, but in a review like this it's that really counts...

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