If you have a high end digital SLR camera, you probably have some notion that faster cards are better, so you'll probably want one of these cards as a minimum.
The answer to that is... well yes, but also no.
The maximum read and write speeds of this card are both given as 266x (or 40MB/s, according to the SanDisk specs), so they allow cameras with continuous shooting to get on with the job of snapping away instead of waiting precious milliseconds for the onboard buffer to empty out. HOWEVER, the speed of the card alone does NOT determine the fastest speed that the camera can write data.
Firstly, the camera does not write the file straight to the card. Files go to a memory buffer onboard the camera first, and are then written from there to the card at a slower rate.
Secondly, the rate at which the files are written from the buffer to the card is the ultimate limiting factor which determines the maximum writing speed with any given camera/card combination.
There is no point buying a camera which can shoot frames in rapid succession if it is hampered by a delay due to a slow card. On the other hand why shell out twice as much for a card in a faster bracket if your camera can't write at that speed?
Basically, you want your camera to perform to specifications. So it is better to pay a little bit extra for a card which is rated for writing speeds slightly faster than the camera is capable of, otherwise your camera will be under performing for the sake of a few pounds/dollars/yen more.
My advice is that if you think you will upgrade to a better camera relatively soon, then invest the extra few quid in a quality fast card! It's only a tiny fraction of the total cost of your camera kit. BUT if you do not plan to upgrade for a while, then just go for a lower bracket (e.g. SanDisk Extreme III or a massive Transcend card). The reason for this is that Moore's Law practically guarantees a steady decline in memory prices over time, and the consumer market has reflected the accuracy of that prediction for over a decade.
Anyway, this card specifically: PERFORMANCE.
I currently use a Canon EOS 40D, and this card allows it to maintain the maximum shooting rate of 6.5fps until the camera's buffer is full, when shooting drops to about 1 frame a second until the buffer is freed up.
In practice, a Canon 40D writes RAW files to this card at about 10.6MB/s. This write speed is not brilliant for the card, but that's a limitation on the part of the camera. At least the card is fast enough to let the camera perform to specifications.
The Extreme III 1Gb version and EOS 40D combination just outperforms this card at 10.7MB/s, but I went for the Extreme IV because I am looking ahead to a future upgrade. Also I can't be doing with swapping out low-capacity cards every few hundred shots.
Strangely this card performs horribly with the Canon 1D Mark III writing RAW files at a very poor 10.5MB/s, and is outperformed by most of the Extreme III range with that camera.
However when used with the 1Ds Mark III it writes at just over 18MB/s for RAW, outperformed only by the 2GB version and the Extreme Ducati range. The new EOS 5D Mark II can write to this card at a delightfully chewy 29.5MB/s.
The Nikon D3x falls just short of this at 29MB/s. Hah!
The Nikon D200 writes at 9MB/s and the Nikon D300 is a vast improvement at just over 25.5MB/s. The Nikon D700 is just a touch faster than that.
The Sony A900 has very respectable performance at about 29MB/s.
In reality the card maximum of 40MB/s is only going to be attained when reading data from the card. The SanDisk Extreme Firewire reader reaches 38MB/s, but the SanDisk Extreme III USB version is probably better value since it is a lot cheaper and reads at a modest 34MB/s.
Because this is an Extreme IV it comes with the individual neoprene-style zippered pocket case (as well as a standard plastic case), and a backup/recovery utility disc.
Note that when I ordered this item the card I received (and based this review on) was the 40MB/s non-UDMA version. Sandisk have now updated the specification for the item to a 45MB/s UDMA version and the Amazon item has been altered to reflect that. BE AWARE that some new/used sellers are shipping the 40MB/s version.
| Brand | SanDisk |
|---|---|
| Product Dimensions | 14 x 14 x 5 cm; 80 Grams |
| Item model number | SDCFX4-4096-902 |
| Manufacturer | SanDisk |
| RAM Size | 8 GB |
| Are Batteries Included | No |
| Item Weight | 80 g |
