The Xenia 15 highlights the other issue that matters for a laptop's SD card reader: It's not just the interface, it's also what the host card reader is rated for.įor the Xenia 15, we couldn't find anything other than that it's a RealTek card reader on USB 3.0. Once you account for overhead it's generally far lower than 60MBps.Īfter the Dell, the XPG Xenia 15 doubles the performance of the G5 15 SE with about 91MBps read speeds. USB 2.0 has a maximum theoretical speed of 480Mbps or 60MBps. You'll see the reason if you look at the labels for the laptops above: It's largely due to the card reader and the interface they're connected to.įor the worst laptop here, the Dell G5 15 SE, it's likely gated by the USB 2.0 interface it's hooked up. IDGĪero 17 and users can be happy they're getting awesome read performance, but you're probably wondering just why the Xenia 15 and G5 SE 15 are sucking wind. The Dell comes out in front by a fair margin over the XPG Xenia 15 and Dell G5 15 SE, but it's very close to the Gigabyte Aero 17. Laptop SD Card slot performanceĪll four laptops feature integrated card readers, but performance varied greatly, as you can see from our first test, Crystal Disk Mark's default sequential read test. Company officials said it's largely concentrating on the even faster SD Express standard, which has a speed limit of 3,940MBps. We contacted SanDisk to ask why it wasn't offering a newer UHS-III bus card. U3 has largely been supplanted by the newer and slightly less confusing 'V' video speed class mark.) Yes, they seriously have U3 and UHS-III which don't mean the same thing.

U3 refers to the card's 'UHS Speed Class' mark for video performance of a camera and card. (And no, don't confuse UHS-III (the bus) with the U3 symbol. Searching just last week, we saw no signs of a UHS-III card for sale. If you're wondering why we're not using an even faster SD card using the newer UHS-III bus, it's because we couldn't find a card that even supported the newer interface, which takes speeds to 312MBps in full duplex mode and 624MBps in half duplex mode.

The SanDisk Extreme Pro SD Card is rated for read speeds right up to the limit of UHS-II at 300MBps with write speeds rated at 260MBps. We used a 128GB SanDisk Extreme Pro card rated for 300MBps reads and 260MBps writes for our testing. We formatted the card in exFAT, which has seemingly become the standard for most large-capacity SD media. The UHS-II bus can hit 312MBps in full duplex mode and 624MBps in half-duplex mode.

The card is a UHS-II card, meaning it rides on the Ultra High Speed II bus and features a second row of contact pins on the back to hit the higher performance ratings of the interface. Because this test would be pointless without a fast SD card, we used a 128GB SanDisk Extreme Pro SD card.

Sd card reader not working