Lexar 32GB Class 10 microSDHC Memory Card Review
We’ve been using a Motorola DROID X Android smartphone for a few months now, which came with a no-name-brand Japan 16GB Class 4 microSDHC memory card pre-installed. Over time, we’ve become accustomed to how long it takes for pictures and videos to save and load on the card, as well as transferring to and from our PC.
To begin with, we copied all the data from this 16GB card to the new Lexar 32GB card, so that both would contain all the same files, pictures, videos, music, etc, which came to about 7GB of data.
For our first tests, we took a few pictures using the DROID X with the 16GB Class 4 card installed, auto-review mode turned off, and they saved in about a second. Then when going into the Gallery, it took about 3 seconds for the picture thumbnails to appear. The same was also true when accessing all of the saved videos. But when we changed out the 16GB memory card and used the Lexar 32GB Class 10 card, we noticed that pictures saved a bit faster, under a second, and when going into the Gallery they loaded with almost no delay. Right then, we could tell that the Lexar Class 10 card was performing better.
Real-world Test 1: We transferred a 1GB file to and from the 16GB and 32GB memory cards while using the Lexar thumb drive adapter installed in our PC’s USB port. The Lexar Class 10 card took 1 minute 35 seconds to write the 1GB of data to the card (10.7 MB/s), while the Japan Class 4 card took 2 minutes to write the same amount of data (8.5 MB/s). Then when transferring the 1GB of data from the memory card back to the PC, the Lexar Class 10 card only took 42 seconds (24.3 MB/s), while the Japan Class 4 card took 1 minute 15 seconds (13.6 MB/s). As you can see, the Lexar card is capable of some fast transfers while using the thumb drive adapter.
Real-world Test 2: We used the same 1GB file transfer as in Test 1, but this time around the memory card was installed in the DROID X and was connected to our PC using a microUSB data cable while placing the phone into Mass Storage mode. When using the Lexar Class 10 card, it took 1 minute 49 seconds to write the 1GB of data to the card (9.4 MB/s), while the Japan Class 4 card took 2 minutes 10 seconds (7.8 MB/s). Then when transferring the 1GB of data back to the PC, the Lexar Class 10 card took 1 minute 15 seconds (13.6 MB/s), while the Japan Class 4 card took 1 minute 20 seconds (12.8 MB/s). Because the data was transferred to and from the PC via USB cable while the memory card was in the phone, we saw a bit of a speed loss, though it is unclear if it is caused by the hardware of the DROID X or the Android 2.2 OS.
Our next set of tests is more regulated, as programs were used to measure data rates and speed results.
Benchmark A: For the first benchmark test, we wanted to see the data rates (MB per Second) for both cards within the Android 2.2 environment while using the DROID X. We used an Android app called System Benchmark by AnTuTu, which measures various speeds on the phone, including the write and read times of the memory card. We preformed the test 3 times in a row on both cards and got the following results. The Lexar Class 10 got write times of 4.9 MB/s, 8.6 MB/s and 9.0 MB/s, with read times of 11.1 MB/s, 10.7 MB/s and 10.5 MB/s. This is quite a bit off from the 10 MB/s write and 20 MB/s read times that Lexar claimed their card is capable of, but again this may be due to the AnTuTu Benchmark program, or the hardware used on the DROID X. Meanwhile, the Japan Class 4 card came up with slower write times of 4.2 MB/s, 7.2 MB/s and 7.4 MB/s, and read times of 9.0 MB/s, 9.3 MB/s and 9.4 MB/s.
Benchmark B: The next Android app we used was Quadrant, which doesn’t specify the actually speed of the memory card, but does tests several things, including memory I/O, and then gives an overall score of the phone. When using the Lexar Class 10 card in the DROID X, the phone got overall scores of 1428, 1456, and 1467. Then when using the Japan Class 4 card, the overall phone scores were 1430, 1443, and 1454. Based on this, the difference in Class rating on the memory cards didn’t have much effect in the Quadrant benchmark scores of the phone.
Benchmark C: At this point, we wanted to see some benchmark tests performed that didn’t rely on an Android app, so we used PC program called ATTO Disk Benchmark. For this test, we kept the memory card installed in the DROID X, and connected it to the PC using the microUSB data cable with phone in Mass Storage mode (similar to what we did real-world test 2). The Lexar Class 10 card got a max write speed of 11.3 MB/s, and a read 12.4 MB/s. We were please to see a write speed here of 11.3 MB/s, but the write speed of 12.4 MB/s is still far below the 20 MB/s claim that Lexar says the card is capable of. While doing the same ATTO tests with the Japan Class 4 card, it got a max write speed of 9.5 MB/s and a read speed of 12.9 MB/s, which is pretty close to the Lexar card.
Card - Lexar 32GB Class 10
Card - Japan 16GB Class 4
Benchmark D: For our final benchmark, we wanted to test both memory cards on their own; outside of the phone environment. We used the same ATTO Disk Benchmark program, but this time used the Lexar thumb drive adapter plugged into our PC’s USB port. This way we were able to see what the ATTO program says about the memory card directly. We were glad to find that the Lexar Class 10 card did achieve a max write speed of 11.0 MB/s and read speed of 20.6 MB/s, which does in fact validate Lexar’s advertised speed claims. The Japan Class 4 card got a max write speed of 9.2 MB/s, and a read speed 14.2MB/s, which is well above average for a Class 4 memory card.
Card - Lexar 32GB Class 10
Card - Japan 16GB Class 4
1. SemperFiV12 (Posts: 592; Member since: 09 Nov 2010)
Difference in speed does not seem significant enough, to me, to justify its price. Just my opinion though.
2. giantgnome (Posts: 67; Member since: 11 Feb 2011)
It may seem that way to you was because the no-name brand card was actually much better than its minimum Class 4 rating. If I could get a class 4 32gb microsd for much cheaper but it ran like a class 8 I would jump on that for sure. But if I ended up with a 32gb class 4 that actually ran at class 4 speeds then the lexar one is a much better deal.
3. Gary (unregistered)
Transcend 32 GB Class 10 is $49.96 with free shipping at Amazon.
4. Richard (unregistered)
@Gary The Transcend at Amazon is a SDHC card and not a MicroSDHC
5. Tomj777 (unregistered)
I have an HD2 and I'm constrained by hardware specification (the phone hardware doesn't lend itself to exploiting a speed greater than Class 4).
That said, performance is noticeably better with my Class 6 8GB Sandisk than a more `generic` branded class 4.2GB card
But here's the rub: Anecdotal evidence on various forums indicate that class 10 cards are optimised for sequential writes - most operations in the Smartphone world relates to Random Access, not Sequential...
Both hardware and card access may have impacted your tests. I notice that my friends Desire HD seems to be able to exploit the Class 10 (according to SD Tools and general responsiveness compared to a class 4
The challenge I have right now is that I've a Class 2 32GB card (sent incorrectly by play.com rather than the advertised class 4) and a Class 10 32GB Lexar card...
Do I send them both back or just send the Class 2 and see how the class 10 performs....