Mainly a SD card transfer test and other thoughts

Thanks guys!

@ RoderickGI: I also tried update via the web interface but as my cable-internet is down I hooked up my iPad to reach internet via 3G and it works for everything a tad slower thou :slight_smile: but the update both in the web ui and My Cloud app don’t approve with 3G for some reason unknown to me. I used the 3G to download it thou.

I finally did some simple tests transfering files from my SD card to the MPW with new the 1.03.13 firmware version.

On the first test I didn’t get a flashing white LED, and the transfer seemed to start automatically, which I don’t have it set to do. I use the wireless button tap to start the transfer (copy).

On the second test though the transfer didn’t start until I tapped the wireless button, and the wireless LED flashed white while the transfer progressed. Excellent.

The card I am using, a 32GB Kingston SDXC Class 10, model SD10G2/32GB, is capable of writing at 12 MB/s via a USB2 connection on my PC. The MPW maintained 10 MB/s and copied the 14.5GiB on the card made up of 1000 NEF files in about 25 minutes.

The first test dropped the battery to 68%, and the second test, plus leaving the MPW turned on for two more hours, so 2.5 hours total, dropped the battery to 52%. Very good.

While that probably isn’t good enough for GoPro videos, the MPW is now certainly good enough for backing up JPG and RAW (NEF) photographs from my Nikon camera while out and about.

Well done WD with the new firmware. Thanks.

Your card is slow. With my fast card (Sandisk Extreme), I copied 41GB in 45 minutes. And the files were in fact GoPro 4 Black 4K video files. The device was plugged in; maybe that affects speed.

markr041 wrote:

Your card is slow. With my fast card (Sandisk Extreme), I copied 41GB in 45 minutes. And the files were in fact GoPro 4 Black 4K video files. The device was plugged in; maybe that affects speed.

Yes I know. That is why I quoted the card’s maximum speed on a USB 2 connection, direct to a PC. I plan to test with a Sandisk Extreme Pro when I get my hands on one, the models with 80 MB/s write speed, and see if they do better, on both USB 2 and USB 3.0.

Thanks for sharing. That is still just over 15 MB/s, so not that different to my result.

Thanks for sharing Roderick.

Your testings show that the reading-speed of that card is a tad slow but that was expected so your result is quite good as well.

PS In these testings the write speed of the card isn’t that important as the reading-speed, that is usually is lower than the writing dito. DS

Yes my current card is a bit slow at 10 MB/s transfer (read) speed. Kingston only claim 15MB/s write speed and Class 10 for it. They don’t even quote a read speed on the datasheet I just looked up, though others do claim 20MB/s. The Class numbering system is based on the minimum sustainable speed, so Class 10 is 10MB/s, and I usually expect around half the marketing number, so 10MB/s is what I expect from the Kingston card, worst case on USB 2.

I think I did test the read speed from the card over USB 2 to my PC, and it was just under 20MB/s, using a USB 3.0 card reader. Yep, just checked. It is 19.5 to 19.9MB/s. So the MPW could do better than 10MB/s with that card, theoretically.

Mark’s Sandisk Extreme though, is supposed to have up to 45MB/s read and write speeds. But again, it is only a Class 10, UHS-I Speed Class 1 device, so it only has to have a minimum sustainable write speed of 10MB/s. All the larger numbers are just burst speeds and marketing. Sustained read speed is what is important in transfering to the MPW.

Using a USB 3.0 card reader, even on a USB 2 port, can have a significant positive impact on both the read and write speeds to and from a memory card, so it looks like both the SD card reader and the internal bus in the MPW are USB 2 devices.

I hope to get my hands on some SanDisk Extreme Pro® SDXC™ UHS-I Memory Cards and test with those. They are still just Class 10 rating plus UHS Speed Class 1, but SanDisk claim write speeds up to 90 MB/s and read speeds up to 95 MB/s, so hopefully they will perform more than a little better, and stretch the MPW’s capabilities.

We shall see.

Most of my tests are with the SanDisk Extreme Pro® SDXC™ UHS-I Memory Card, and it’s way faster than what the MPW can coop with and still the MPW tops out at about 15 MB/s from the claimed 25. At least it’s usable for my intended uses of the MPW, but still hope they can crank up the transfer speeds a bit more :slight_smile: