The Samsung P9 Express 512GB is a microSD Express card rated for sequential reads of up to 800 MB/s in SD Express mode. That is a manufacturer maximum measured on a PCIe test board—not a speed every device will deliver. Samsung also lists UHS-I operation at 90 MB/s, so the host device’s slot and interface support matter as much as the card.
What the Samsung P9 Express 512GB offers
Samsung’s US product page identifies the 512GB microSDXC model as MB-MK512T/AM. It supports PCIe Gen 3.0 x1, NVMe 1.3, SD 7.1, and UHS-I. Samsung lists U3, V30, and A1 speed classes; its datasheet also lists Class 10.
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| Specification | Samsung’s stated value |
|---|---|
| Capacity | 512GB |
| Sequential read, SD Express mode | Up to 800 MB/s; Samsung says the 512GB card was measured using a PCIe test board, and actual results vary by host device, interface, usage conditions, and other factors. Samsung Newsroom US |
| Sequential read, UHS-I mode | 90 MB/s, according to Samsung’s US product page |
| Approximate card-only weight | 0.25 g, according to Samsung Semiconductor’s datasheet |
| Warranty | Three-year limited warranty, according to the datasheet; applicable terms vary by market and workload |
Samsung says usable capacity may be lower than the labeled capacity because storage-control functions and system files use part of the space. The 512GB figure is the card’s stated capacity, not a promise that all 512GB will be available for user files.
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Only a device and slot that support SD Express can use the card’s SD Express performance. A microSDXC slot or a device category appearing on Samsung’s compatibility list does not, by itself, establish SD Express support or the top speed for a particular model. Samsung lists phones, tablets, action cameras, drones, laptops, and gaming consoles as device categories, but model-level compatibility must be checked with the device maker.
#1 Best Overall
- TRANSFER SPEEDS UP TO 800 MB/S: With sequential read speeds up to 800 MB/s, get into your game up to 4× faster than our standard microSD cards (UHS I)¹.
- DYNAMIC THERMAL GUARD: Keeps its cool even when the action heats up. Dynamic Thermal Guard helps reduce overheating for fast, smooth gameplay.
- ALL YOUR GAMES ON ONE TINY CARD: Store all your games and downloadable content (DLCs) with up to 512GB of reliable storage. No deleting. No compromises.
- 6-PROOF PROTECTION WITH 3-YEAR LIMITED WARRANTY: Built to last, made for peace of mind. Anything can happen when you’re gaming on the go. With 6 types of protection²⁻⁹, the P9 Express can handle it all—helping maintain your game progress.
- NEXT-GEN AND BACKWARD COMPATIBLE: Your microSD Express card is compatible with Nintendo Switch 2¹⁰ and microSD UHS-I¹¹ devices, including tablets, drones, cameras and more.
In a UHS-I host, Samsung lists the card’s sequential read speed as 90 MB/s rather than the 800 MB/s SD Express maximum. Even with SD Express support, 800 MB/s remains an upper rating, not a guaranteed transfer rate for every file, workload, or device.
Is $104.48 a verified 30% discount?
The exact $104.48 offer and the claimed 30% reduction are not confirmed by the available Samsung pricing references. Samsung’s US launch announcement set the 512GB model’s MSRP at $99.99; a Samsung US listing surfaced at $149.99. Those are different reference prices, and neither establishes that $104.48 is a current offer or that it represents a 30% saving against a valid comparison price. Check the live seller, region, stock, date, and stated comparison price before treating it as a deal.
Rank #2
- TRANSFER SPEEDS UP TO 800 MB/S: With sequential read speeds up to 800 MB/s, get into your game up to 4× faster than our standard microSD cards (UHS I)¹.
- DYNAMIC THERMAL GUARD: Keeps its cool even when the action heats up. Dynamic Thermal Guard helps reduce overheating for fast, smooth gameplay.
- ALL YOUR GAMES ON ONE TINY CARD: Store all your games and downloadable content (DLCs) with up to 512GB of reliable storage. No deleting. No compromises.
- 6-PROOF PROTECTION WITH 3-YEAR LIMITED WARRANTY: Built to last, made for peace of mind. Anything can happen when you’re gaming on the go. With 6 types of protection²⁻⁹, the P9 Express can handle it all—helping maintain your game progress.
- NEXT-GEN AND BACKWARD COMPATIBLE: Your microSD Express card is compatible with Nintendo Switch 2¹⁰ and microSD UHS-I¹¹ devices, including tablets, drones, cameras and more.
How to decide whether 512GB is the right capacity
Choose based on the amount of content you expect to keep on the card and the interface supported by your device. If your device supports only UHS-I, the card’s SD Express headline rate will not apply. If it supports SD Express, verify the exact model’s compatibility and compare cards using the same interface, capacity, and test conditions rather than comparing headline numbers alone.
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Samsung’s datasheet states a three-year limited warranty. Samsung Canada says coverage does not extend to dashcams, CCTV, surveillance cameras, and other write-intensive uses; check the warranty terms for your market and intended workload before relying on coverage.
Rank #3
- NEXT GEN GAMING: Works with Nintendo Switch 2.
- READY FOR TOMORROW. Ready for future products with a PCIe-NVMe interface; performs at UHS-I speeds with microSD UHS-I and UHS-II devices.
- EXPONENTIALLY FASTER PERFORMANCE. Up to 4.4 times faster transfer speeds than our fastest microSD UHS-I cards [9]. Transfer a 2-hour HD movie in less than 3.5 seconds [1]; save up to 2.8 minutes transferring 60 minutes of 4K UHD video [4] shot at 30 fps when paired with the SanDisk PRO-READER SD Express Dual Card (sold separately) [9]
- DURABILITY YOU CAN COUNT ON: Cards are waterproof, temperature-proof, humidity-proof, drop-proof, shock-proof, magnetic-proof, x-ray proof, and wear-out proof [5].
- HEAT MANAGEMENT REIMAGINED. SanDisk ThermAdapt helps keep devices from overheating with a specially designed enclosure and controller that uses dynamic adaptive thermal management.
What the weight claim does—and does not—show
Samsung Semiconductor lists approximate card-only weight as 0.25 g. The available specifications do not compare this card’s weight and performance with competing products, so they do not substantiate the claim that it is “like no other” in its weight class.
Quick Recap
Best Value
- Compatible with a variety of devices: Nintendo Switch 2 has been verified, PC, smartphone, camera, etc
- Transfer speed: Up to 800 MB/s (SD Express). *Transfer rate may be limited to UHS-I speed depending on host device compatibility
- Interface: PCIe Gen 3.0 x1, NVMe 1.3, SD 7.1 / UHS-I SDR 104
- [Durable] Water resistant, heat resistant, X-ray proof, magnetic proof, fall proof, wear-resistant
- [Warranty] Data loss. Only products sold by authorized stores are covered by warranty and support
Rank #4
- YOUR GAMING EXPERIENCE, REDEFINED: Upgrade your Nintendo Switch 2! The Samsung P9 Express micro SD card offers lightning-fast charging times and smooth gameplay for unlimited fun with 800 MB/s.
- Speed that makes the difference: Experience fast charging times on game consoles and 4K performance in cameras with the Samsung P9 Express microSD Express memory card. Robust, reliable and with storage space for all your adventures.
- Simply plug in and go: insert the Samsung P9 Express micro SD Express card into the slot of your Nintendo Switch 2 or other compatible device. Format them as needed and enjoy more storage instantly.
- MORE THAN JUST FAST - ABSOLUTELY SECURE: Your data is safe. The 6-way protection protects your games and memories from water, extreme temperatures, X-rays, magnets, drops and wear.
- INCLUDED: You will receive one (1) Samsung P9 Express microSDXC Express memory card with a capacity of 256 GB. Ready for immediate use in your Nintendo Switch 2, other consoles or cameras.
Sources
- Samsung US P9 Express product page — model, interfaces, speeds, classes, device categories, capacity note, and surfaced listing price.
- Samsung Newsroom US launch announcement — launch MSRP and the test-board basis and variability caveat for the 800 MB/s rating.
- Samsung Semiconductor P9 Express datasheet, Rev. 1.0 — interface details, weight, speed ratings, and warranty.
Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon at the time of purchase will apply.
