Test Setup

Previous generation of cards could be tested using traditional card readers. At first USB 2.0 based ones were sufficient, then IDE adapters with DMA managed to deliver the maxium of a card. With the addition of UDMA, such interfaces are no longer fast enough. Most IDE to CF adapters do not offer UDMA at all and even if they do, may not support all different UDMA modes. We then moved on to ExpressCard34 adapters to bench a card. Recently SATA based CF adapters have become available. We will be using these to review Compact Flash cards for now.

A decked out ASUS P55 + i7-860 system is used for this review along with a generic SATA to Compact Flash adapter. This should be more than enough to push the card.

Performance

The card performs exceptionally well. With read speeds well over 64 MB/s and just under 72 MB/s peak, it can be considered a a great storage platform for small form factor PCs. The access times of 0.3 ms will also result in excellent performance. To recap, the 350x Compact Flash card from A-DATA managed 42 MB/s and 0.7 ms, thus the 633x manages to push the limit even higher. At the attained speeds, the unit is just as fast as the usual 7200 RPM desktop drives out there, without the slowdown effect the further you move along the drive size and high access times.


Taking a look at the performance of various file sizes, the weakness of flash memory devices does become evident once more. Such memory only unfolds its full potential with file sizes larger than 16 KB. ATTO confirms the read scores of HDD Tach, while revealing a write performance of around 67 MB/s. This is certainly impressive, but it should be mentioned that A-DATA points out a read performance of 93 and a write speed of 92 MB/s. We did not manage anything like that, but considering the fact that some scenarios which utilize the card directly - like a DSLR - cannot be benched properly and that the camera is most likely holding the card back in such an environment. Nonetheless a read speed of over 70 MB/s is excellent and the write speed of 60 MB/s is fabulous as well. The card is fast, but only time will tell if others from different manufacturers - rated for the same speed - manage to push more data or not. The x-factor label is something many of them use, but two cards with the identical multiplier often tend to perform radically different.

To give you some simple comparison data, a 7200 RPM SATA II drive clocks in at an average read speed of 67.2 MB/s. That means that the A-DATA 633x Compact Flash card is actually faster, while it also has the advantage of a constant read performance across the entire storage space. Hard drives tend to drop in speed the closer the reading head gets to the outer edge of the platters (seek time, access times), while the sequencial transfer rate behaves in an exactly opposite manner. The A-DATA 633x CF card also manages to perform similar to a 7200 RPM hard drive in terms of write speed. Such a traditional hard drive pushes between 60 and 75 MB/s and the A-DATA 633x CF offers a constant 60 MB/s.

This means that the A-DATA 633x should perform just as good as a 7200 RPM drive, with the added bonus of a low random access time of 0.3 ms. It will not best any of the SSDs out there though, as those tend to offer performances well above 100 MB/s - even when looking at the value segment of such storage units.

PCMark Vantage

We have reviewed various constallations of drives with PCMark Vantage. The A-DATA 350x which we reviewed here is part of the below table, but keep in mind that we used the Lexar Firewire 800 CF reader back in 2008, while using the Addonics Pocket DigiDrive eSATA to get a usable score for the 633x CF variant. Using the CF to SATA adapter in Windows 7 or Vista only resulted in a 4 MB/s performance barrier for some strange reason, even though the adapter works fine in Windows XP SP3.