Collection: Memory Cards

Which memory card do you actually need?

Most PC builders land on memory cards sideways. You've sorted the rig, then a camera, handheld, drone or dashcam needs storage and you find a wall of near-identical cards with wildly different prices. The differences are real, though, and they come down to three things: the bus interface, the guaranteed minimum write speed, and the quality of the NAND and controller inside.

Entry cards are typically UHS-I, Class 10, U1 or U3. The bus tops out around 104MB/s in theory, and real reads land at roughly 90MB/s. Writes are often far lower and the controller doesn't hold them steady. That's fine for photos, a Raspberry Pi, a basic action cam or a Switch library. Sweet-spot cards are UHS-I with V30 and A1 or A2 ratings. V30 guarantees 30MB/s sustained writes, which is what 4K video needs. A2 means better random I/O, so game loading and app launching on handhelds feel snappier.

Enthusiast cards move to UHS-II (the second row of pins), CFexpress, or SD Express. UHS-II reaches up to 312MB/s, while CFexpress Type B and SD Express use PCIe and NVMe signalling, closer to how an SSD works. These cards matter for high-burst RAW stills and 6K or 8K video, where the camera's buffer needs to clear fast. Diminishing returns hit hard here. If your device only has a UHS-I slot, a UHS-II card just runs at UHS-I speed, and you've paid extra for nothing. Match the card to the slowest part of your chain, which is usually the device slot.

Upgrading and technical nuances

The first thing to understand is sustained versus peak speed. The big number on the label is a burst read figure. What matters for video is the sustained write floor, shown by the V rating (V30, V60, V90). Cheaper cards use a small fast cache, often TLC NAND running in a pseudo-SLC mode, then drop dramatically once that cache fills. Better cards use stronger controllers and more parallel NAND dies, so they hold their write speed through a long take.

Capacity labels hide a format trap. SDHC cards (up to 32GB) use FAT32, while SDXC (64GB and up) uses exFAT. Older cameras and some embedded gear can't read exFAT, so check the manual before buying a big card for an older device. For handhelds like the Steam Deck or ROG Ally, A2 cards from SanDisk Extreme, Samsung PRO Plus or Lexar Professional are solid picks, since random I/O matters more than headline sequential speed. For anything that supports microSD Express, look for the newer PCIe-based cards, but confirm your device actually supports it first.

If you're recording constantly, such as dashcams or security cameras, buy a high endurance card (SanDisk High Endurance, Samsung PRO Endurance). These trade peak speed for NAND and controller tuning built for continuous overwrite, and a standard consumer card will wear out quickly in that job. For pro cameras, ProGrade Digital, Angelbird and Sony Tough are the names to look for in UHS-II and CFexpress. Sony Tough cards use a single-piece moulded construction that's noticeably more robust.

Don't confuse these with Desktop Memory, which is volatile RAM for your PC. Memory cards are flash storage, and they behave much more like a small, slow-ish Solid State Drive (SSD) in a different form factor. If you're moving big files to a desktop regularly, a decent card reader matters just as much as the card.

Practical things to check before buying

Start with the physical form. SD, microSD, CFexpress Type A and CFexpress Type B are not interchangeable. Type A is mostly Sony, Type B is used by Canon, Nikon and Panasonic, and neither fits the other's slot. A microSD card in an SD adapter works fine, but the adapter's contacts can be a failure point, so use a reader sized for the card when you can.

Next, check your reader. A UHS-II card in a cheap USB 2.0 reader will crawl at around 35MB/s. You want a reader with USB 3.2 Gen 2 or better, and a UHS-II reader if you bought a UHS-II card. Many motherboard and laptop built-in readers are only UHS-I, so a dedicated reader is often the real upgrade. Pair it with a decent short cable from Cables & Connectors rather than the bargain-bin lead, because poor cables quietly cut throughput. If you offload footage to a NAS, a Networking setup with 2.5GbE or faster stops the network from becoming the next bottleneck.

Heat is a quiet killer. Cameras shooting high bitrate 4K or 6K can push cards hard, and some cards throttle once they heat up. CFexpress cards in particular run warm, so give them a moment to cool during long shoots. In a PC setup, if you're using a USB card reader dock inside a build, make sure the Computer Cases front panel ports have decent airflow and aren't packed behind hot components.

Finally, counterfeits. Fake cards report a large capacity but quietly overwrite data once the real flash is full. Buy from an authorised Australian retailer, avoid prices that look too good, and test new cards with H2testw or F3 before trusting them with anything important. Keep the write-protect switch on full-size SD cards in mind too, since a nudged switch causes plenty of "card error" panic.

Brands and local warranty

The reliable names are SanDisk (including the Extreme and Extreme Pro lines), Samsung (PRO Plus, EVO Select, PRO Endurance), Lexar (Professional range), Kingston (Canvas series), ProGrade Digital, Angelbird and Sony. SanDisk and Samsung hold the most mainstream ground, while ProGrade and Angelbird focus on professional creators.

Local warranty matters more than most people think. Flash cards can fail without warning, and many reputable brands offer long or limited lifetime warranties. Those only help if the card came through an authorised Australian channel. Grey imports and marketplace sellers can leave you fighting an overseas claim, or voided altogether if the card turns out to be fake. Under Australian Consumer Law you also have rights beyond the manufacturer's warranty, and dealing with a local seller makes those much easier to exercise. Keep your invoice and take note of the card's batch number.

Frequently asked questions

What capacity memory card should I buy?

Work out how much you shoot or store, then add headroom. For 4K video, 128GB gives you roughly an hour or two depending on bitrate, so 256GB is a comfortable sweet spot. For handheld gaming, 512GB to 1TB makes sense. Several mid-sized cards also reduce the risk of losing everything to a single failure.

Do I need V60 or V90 for 4K video?

Usually no. Most 4K recording at standard bitrates is fine on V30. V60 and V90 matter for higher bitrate formats, 6K or 8K, or high-frame-rate all-intra recording. Check your camera's manual for the recommended minimum.

Will a UHS-II card work in a UHS-I device?

Yes, it's backwards compatible, but it will only run at UHS-I speed. It's a fair choice if you plan to upgrade your camera or reader later, otherwise save the money.

Are microSD and SD cards the same technology?

They use the same underlying standards and speed classes, just in different sizes. A microSD card works in an SD slot with an adapter, but not the reverse.

How can I tell if a memory card is fake?

Test it with H2testw (Windows) or F3 (Mac and Linux) to verify real capacity and speed. Spelling errors on packaging, unusually low prices and unfamiliar sellers are red flags. Buying from an authorised local retailer is the simplest protection.