If you have one of the professional Sony cameras, you will probably also have a CFexpress Type A slot in addition to an SD card slot.
CFexpress memory cards are something very interesting! At their core, these are mini NVME SSDs!
As a result, CFexpress memory cards are not only significantly faster than SD cards, but also more reliable and durable.
In contrast to all other camera manufacturers, Sony uses CFexpress Type A and not Type B memory cards. Type A memory cards do have their advantages, they are much more compact and it is possible to install SD/CFexpress Type A “combo slots”.
However, CFexpress Type A memory cards are extremely expensive! A Sony CFexpress Type A memory card with 160 GB of storage costs a whopping €330! WOW!
In the meantime, however, there are some cheaper alternatives, some of which are said to offer even more performance.
One of the fastest CFexpress Type A memory cards, at least on paper, is the Lexar Professional GOLD R900/W800.
This should be a whopping 900 MB/s reading and 800 MB/s writing, which is around 100 MB/s more for both values than the Sony memory card. The Lexar is over 100€ cheaper.
Sounds very tempting! But how does it look in practice? Is the memory card as good as advertised here?
Many thanks to Lexar for providing the memory card for this test.
The Lexar Professional GOLD R900/W800 in review
In terms of form factor, the Lexar Professional GOLD R900/W800 is of course a classic CFexpress Type A memory card.
The choice of materials is striking compared to Sony’s model. Lexar uses a metal case, at least in part. This not only makes the memory card appear more valuable, but also helps with heat dissipation.
CFexpress Type A memory cards tend to have some temperature issues, so this is a welcome feature!
Type A and Type B
CFexpress memory cards come in two versions (actually 3, but type C is not widely used).
Type A – Used by Sony – Very small and compact – Maximum 1000MB/s Type B – Used by Canon, Nikon, Fuji, etc. – Slightly larger – Maximum 2000MB/s
So make sure you buy the right CFexpress type for your camera! Do you have a Sony camera then you’ve come to the right place.
CFexpress Type A memory cards are slower and much more expensive, but unlike Type B memory cards, it is possible to build a “combo slot” of CFexpress A and SD cards, as Sony does on many of its cameras.
At its core, an NVME SSD
A CFexpress memory card is essentially an NVME SSD, as you normally install it in a notebook/PC. A CFexpress memory card is also connected via PCIe.
One CFexpress Type A memory card uses a PCIe 3.0 x1 connectionwhere are they from? theoretical maximum data rate of +- 1000 MB/s originates.
A CFexpress Type B memory card uses the PCIe 3.0 x2 connection, so it can theoretically achieve twice the data rate. The fact that such a memory card is a complete PCIe SSD at its core not only has advantages in terms of data rates.
This also makes CFexpress memory cards a lot more durable. These support all functions such as wear leveling, TRIM and SMART values.
You can read the status of the memory card on the PC. You can also see here how often this has been described, whether the first cells are defective, etc.
This can be a great benefit.
A first benchmark
First, let’s take a look at the maximum data rates in a small benchmark. For this I use the ProGrade Digital (PG09) CFexpress Type A and SDXC/SDHC UHS-II card reader (advertising link), which in my experience is the fastest CFexpress Type A card reader (faster than Sony’s own).
In the test, the Lexar Professional GOLD R900/W800 CFexpress Type A reached 858.81 MB/s reading and 869 MB/s writing.
Compared to the Sony memory card, we read +- the same speed. In fact, the Sony memory card is even 1 MB/s faster reading.
It is easy to assume here that the card reader is at its limit. Where we see a clear difference is in the write rate. Here the Sony memory card “only” achieves 753 MB/s, which is a bit less than the Lexar’s 869 MB/s.
Doesn’t overheat!
CFexpress Type A memory cards tend to overheat. Especially the original Sony memory cards overheat very quickly under constant load! Overheating here means throttling the data rate to keep the temperature under control.
Since I could also observe this with the ProGrade memory card, I thought this was simply due to the design.
But here I was pleasantly surprised, because the Lexar Professional GOLD showed no temperature problems.
In the following you can see the data rate when fully writing the memory cards (Sony and Lexar) with H2TestW.
Here you can see that the Lexar Professional GOLD consistently delivers just under 600 MB/s on H2TestW. The Sony TOUGH CEA-G Series, on the other hand, only delivers the full data rates for a short time and then slowly breaks down to prevent damage from overheating.
At some point, the data rate drops to just 150 MB/s with the Sony memory card.
In practice
In practice, a fast memory card primarily makes sense for series images, as of course with 8K video.
I tested the memory card in the Sony A7R V. In the “worst case” this can generate 10 frames/s with around 61 MB per frame. 10 * 61 MB/s = 610 MB/s and the camera can theoretically take pictures constantly.
And this is also confirmed in practice! So it is not possible to fill the buffer with the Sony or the Lexar memory card with the A7R V!
I shot a constant 10 frames/s for 60 seconds with the A7R V and in the end the buffer was practically empty. This applies to both memory cards!
First of all, they behave absolutely identically. It is possible that at some point the Sony memory card will overheat and then slow down, but you have to push it extremely or use another camera with an even higher continuous shooting speed.
Conclusion
The Lexar Professional GOLD R900/W800 is the best CFexpress Type A memory card I have tested so far!
In terms of performance, it’s a bit better than the Sony and ProGrade models, but that’s not really important. Because in practice, the Lexar and, for example, the Sony CFexpress Type A memory card don’t do much.
Both deliver perfect performance in video mode (8K video) as well as in continuous shooting! It is not possible to fill the buffer of the A7R V with such a CFexpress memory card. The full continuous shooting speed is available here “unlimited”.
Then why is the Lexar Professional GOLD R900/W800 better than the Sony memory card?
On the one hand, the Lexar is about €100 cheaper. Both memory cards are not really cheap, but €100 less is a significant difference.
In addition, the Lexar memory card does not overheat! Yes, with constant load, especially when reading out the data on the PC, the Sony CFexpress Type A memory cards can quickly become so hot that they throttle massively (sometimes to just 150 MB/s).
The Lexar memory card also gets hot, but I could not observe this behavior!
This combined with the trouble-free use in my A7R V and the lower price makes me recommend the memory card with a clear conscience!