Kingston 32 GB microSD Class 10 Card Review
The size of our digital collection is increasing everyday. As the quality of digital media increases, so does its size. To fulfill the increased size requirement, various manufacturers have upped the sizes on their storage cards. 32GB SD and microSD cards are a common requirement for consumers who shoot a lot of pictures or video or store a lot of music on their smartphones and are widely available. However, along with the increased storage consumers also demand faster access to their media stored on these devices. The SD association classifies these portable storage devices into various classes based on the minimum data transfer.
Shown below is the packaging the Kingston card came in. The package includes a microSD to SD card adapter and a microSD card reader which are nice accessories to have. This allows the microSD card to be used where a SD card would be required and saves the consumer from buying a high speed high capacity SD card or a card reader.
Specifications
- Capacity — 32GB
- Dimensions — 0.43 x 0.59 x 0.039 ( 11mm x 15mm x 1mm)
- High-Speed Class Rating—
- Class 10: 10MB/sec. minimum data transfer rate
- Operating temperatures — -13°F to 185°F (-25°C to 85°C)
- Storage temperatures — -40°F to 185°F (-40°C to 85°C)
- Weight — .1 oz (2.7g)
Testbed System
- HP G62-340 US Laptop
- Athlon P340 2.2 GHz
- 3GB DDR3 RAM
- Samsung Class 2 16GB microSD card (Stock card with Motorola Droid)
Testing methods
To test out the card speeds, we tested them in two phones – the Motorola Droid 1 and the Samsung Galaxy S Fascinate. The Motorola Droid 1 represents the older generation of Android smartphones in our testing while the Samsung Fascinate represents the newer generation. The same tests were run on both of the phones to see if the high speed microSD card was being bottlenecked by the older generation hardware of the Droid 1.
We ran our normal suite of storage tests in a PC environment. The card was tested in the microSD to SD card adapter that came with the packaging directly inserted into the SD card reader on the laptop. Then the card was tested while the smartphone was connected to the laptop while the USB mode being mounted.
We also tested the cards in a DSLR camera, the Nikon D5100.
A recent tweak was found for the read cache value for Android OS which enables a substantial increase in data read speeds. Please refer to the following link for a detailed explanation on this:
http://www.xda-developers.com/android/increase-the-reading-speed-of-your-sd-card/
The read cache on some ROMs on Android phones is set at 4KB or 128KB. By increasing the size of cache, higher read speeds can be achieved. We used this tweak in our testing with Android hardware to see if it varied our results.
Testing in the Motorola Droid 1 (Android Second Gen Hardware)
We used two apps freely available in the Android Market to test the speed of the microSD card.
- SD Tools
- Jdisk Bench 3.0
SD Tools
This app was used with its default settings to test the card.
JdiskBench 3.0
This benchmark can be used to test the read and write speeds of the SD card with different unit data sizes. Our testing included writing 50MB of data in 4KB and 1024KB unit sizes and then reading it back. However, we also used the Android cache size trick to vary the cache size to see the effect it had on the transfer speeds.
We do not see difference between the cards in most of tests. In most of the tests, the class 10 card lags behind the class 2 card. Only in the last test – when reading data in 1024KB unit size with the Android cache set at 4096KB – that we see for the class 10 card beating the class 2 card handsomely. One of the reasons that both the cards end up performing similarly, could be due to being limited by the older generation SOC being used in the Motorola Droid 1. To see if newer hardware would make a difference, we also tested in a Samsung Galaxy S Fascinate. Let’s take a look at those results on the next page.
Testing in Samsung Galaxy S Fascinate (Android Third Gen Hardware)
We used the same two apps that were used for testing in the Motorola Droid 1 on the previous page. These apps are freely available on the Android Market to test the speed of the microSD card. They are:
- SD Tools
- Jdisk Bench 3.0
Our suspicion that the older hardware is bottlenecking the cards is confirmed here. The results with the newer hardware are about 2 times faster than what the older hardware could manage. But we are still amazed because the class 10 card is either lagging behind the class 2 card or equal in performance.
Note: We did not report the read speeds for the tests with unit size of 1024KB because the app was giving us unlikely values varying wildly from 190 MB/s to 300 MB/s. This is probably a bug in the app when dealing with reading using a larger unit sized data, so we decided to ignore these results.
CrystalDiskMark
CrystalDiskMark is a HDD benchmark utility for your hard drive that enables you to measure sequential and random read/write speeds.
Key Features
- Measure sequential reads/writes speed
- Measure random 512KB, 4KB, 4KB (Queue Depth=32) reads/writes speed
Using this utility, we measured read and write speeds of the card in two ways. We used the integrated card reader of our test laptop for the first method. In the second method, the microSD card was mounted in the Samsung Galaxy S Fascinate phone and connected to the laptop with a USB cable.
Method 1: Card Reader
Both of the cards end up performing nearly the same for most of the tests except a few where class 10 card shows its awesome writing speed advantage. In the Random 4KB tests the class 10 card is around 6-7 times faster at writing the data. Incidentally, it’s quite a bit slower at reading data for the same tests.
Method 2: USB Mode
The 4KB random data write speed advantage of the Class 10 card take in the card reader method is gone here as both the cards write at the same speed. However, the class 10 card is still slower at reading the 4KB random data. The class 10 card is also quite a bit slower at reading random 512KB data. In the other tests, both of the cards show about even performance.
Testing the cards in a DSLR
For this test we used a Nikon D5100 DSLR, which is one of the latest consumer mid-range DSLR models. The Nikon D5100 has a really large memory buffer which allows shooting of a large number of JPEGs continuously. It is possible to shoot 100 JPEGs continuously and about 14-15 RAW files. For a better understanding of why you would need a faster card in a DSLR, please watch the following video as it explains this best.
We were able to shoot about 100 JPEGs on each of the cards but the difference was in the recovery time like shown in the video above. While the recovery was almost instantaneous on the class 10 card, it took about 8 seconds with the class 2 card. We saw similar performance while shooting RAW files too. It took longer for the class 2 card to finish writing the RAW files to the card.
Conclusion
In this review we tried to answer the question that is lingering on the minds of a lot of smartphone users. A lot of users ask themselves if they can benefit from the extra speed offered by a class 10 card. With the minimum guaranteed 10MB/s speeds, we expected the tasks involving file access in our smartphone testing to be sped up. But after testing the class 10 card, we were left a bit underwhelmed. In most of our tests in a smartphone, the class 2 card was able to match the performance of a class 10 card if not better it.
Through our testing, we found that the real benefit of this the card is when used for continuous shooting in a DSLR. During continuous shooting, the recovery time for the class 10 card was almost instant, while it took around 8 seconds for the camera to recover after writing all the JPEG images taken during continuous shooting with a class 2 card. This can make all the difference between getting that perfect shot and missing it altogether while shooting fast-paced action. An example of this was made perfectly clear to me when I shot the performance of USAF Thunderbirds at an air show. It is easier to shoot continuously to get that one great shot while the jets whiz by rather than trying to track the jets manually and taking single shots.
At this point of time we believe that smartphones don’t really have a need for a class 10 card and can be well served with a class 2 card. However, if you are shooting pictures in a DSLR or a full HD video camera, we would definitely recommend a class 10 card.
This article gets to the point