Back to the question of performance. Just like our memory card roundup a similar testing methodology was used (see the last page of this review for details). As a guide, the Extreme IV’s results have been graphically compared to the 4GB cards featured in that roundup. This gives an indication of read/write performance when using a SanDisk ImageMate multi-slot reader and the Extreme FireWire reader to transfer images in a single directory. Furthermore, the Extreme IV card has been tested in a Canon EOS-1D Mark II and a Canon EOS 5D for comparison.
Looking at the graphs on the third page, it’s clear that both camera’s are limiting (not taking full advantage of) the Extreme IV CF card. There is a slight improvement over Lexar’s 4GB Professional 133X CF card, but it’s hardly noticeable in practice. In addition, both cameras show a similar write performance to each other, both hitting the 7MB/sec mark.
As somewhat expected the Extreme FireWire reader coupled with the Extreme IV card has produced some of the fastest card-to-PC transfer rates I’ve seen. Over the FireWire 400 bus of our test system, an average read speed of 29.5MB/sec and a write speed of 15MB/sec were achieved. Ok, not quite the 40MB/sec rating that SanDisk states, but that’s under ideal conditions. That said, these figures should increase over a FireWire 800 connection, especially one found in a high throughput system like the Power Mac G5 or Mac Pro. Check out this enthusiastic exploration of the various read speeds obtained in a number of systems.
It’s also worth noting when the USB 2.0 SanDisk reader is used, the Extreme IV card reverts to a more sedate 8MB/sec read and 6.7MB/sec write speed – more or less similar to the other top-perfroming CF cards and thereby suggesting that the reader and USB interface are key limiting factors.
That all goes to show that when the card reader has been designed with the actual card in mind there’s little to beat that combination. It ensures full compatibility and, if like SanDisk, you throw in support for the UDMA 4 transfer protocol over FireWire’s renowned sustained data transfer rates, then there’s little that comes close. In my opinion, and if you’re a photographer who wants to speed up the “transfer to my PC” part of your digital workflow, the SanDisk Extreme IV 2GB CF card with Extreme FireWire reader bundle makes a great choice.
For £165 at the time of the review, SanDisk’s Extreme IV CF card and reader bundle may not be cheap, but it does represent reasonable value for money – especially when you know that high file transfer performance is pretty much guaranteed with a FireWire-enabled setup.