Orangeman Burns - Sriram Sridharan's Blog

With basic and advanced multimedia phones cheaply available in India, it is no surprise that almost everybody seems to have one. Be it a Nokia or a Motorola or a SE or maybe even a Chinese knockoff, multimedia phones are all the rage at the moment. So everyone seems to have a multimedia capable phone, but what do they use it for? Calling, messaging, shooting a couple of pictures, listening to music and a little web browsing. But most phones usually come with a 512MB or 1GB card out of the box which is hardly enough to put one quarter of your music collection on board. The solution - Memory cards.

Memory card capacities and prices have come a long long way. I remember my old Nokia 6600[It became the world's then most popular and recognizable Symbian phone] which came with a 64MB MMC card. I actually had to think twice about the songs that I copied on it. With about 50Mb available, there was only space for an album's worth of music. The next year I splurged on a no-name 512MB MMC which cost me about Rs. 1000[~US$ 20]. This was like a whole new playground for me. I had enough space for my top 30-40 songs, encoded at 64 or 128 Kbps and a couple of cartoons/movies encoded in 3gp. Nokia didn't have a stereo headset to go along with the 2.5mm socket on the phone so I remember using a operator's headset to listen to music and later switching to a Chinese "stereo" headset which simply gave mono out to both the channels.

Then I bought a Nokia 5610. Even though Nokia marketed it as a Music Phone, it came with a 512MB MicroSD if I remember correctly. I bought a 1GB Toshiba MicroSD for about US $35[~Rs. 1750] shipped, at an online store based in Japan. In 2008, when the memory card prices started to go down, I bought a Kingston 4GB MicroSDHC Class 4 card for about US $32[~Rs. 1600] shipped, from a HK based retailer. The same Kingston 4GB MicroSDHC Class 4 card now retails for less than Rs. 500[~US $10]

I'm sure you're wondering why I gave you this little trip down my memory lane and peppered you with a bunch of obtuse jargon and abbreviations. Let me explain. There are a bunch of memory card formats in use today but only a handful of them are used regularly. We'll be talking primarily about the SD family because they are easily the most popular card format used across a wide variety of devices from mobile phones to MP3 players to GPS units to digital cameras.

SD stands for Secure Digital and was introduced in 1999 as a successor to the MMC card format that I referenced a few paragraphs earlier. It comes in three form factors- SD, MiniSD and MicroSD. The SD cards are incredibly versatile. Once you have the card smallest form factor, it is possible to go up the hierarchy by using adapters. For example, a microSD card will fit in a MiniSD adapter to form a MiniSD card, a MicroSD/MiniSD card in a SD adapter to form a SD card. The relative sizes and measurements are shown below, courtesy of wikimedia:

There are 2 commonly used types of SD cards. One is the SD card and the other is the SDHC card. SD cards are cards of upto 4GB sizes[It is difficult to find a SD card of a 4GB capacity though] and the SDHC[Secure Digital High Capacity] cards are extended capacity cards of more than 4GB to a limit of 32GB. Most SD only devices will not read SDHC cards but SDHC compatible devices will read SD cards. So it is imperative to buy a device with SDHC compatibility if you need to use higher capacity cards. Most of the newer multimedia models like Nokia's Music Express series or the N series are compatible with SDHC cards. To check if your device is SDHC compatible, look at your device's manual or manufacturer support site or look at Kingston's device database here: http://www.ec.kingston.com/ecom/configurator_new/mfrmod.asp.

There are also two other lesser known types: the SDIO[Secure Digital Input Output cards] that are usually used to increase the functionality of a portable device and the SDXC[Secure Digital eXtended Capacity] cards that were recently demo'ed at CES in 2009. We will not be talking about the last two variants as they are not common place enough in our devices.


Now that you have decided to upgrade to a SDHC card, there are somethings you need to know about. The first is card speed. The SDHC cards are divided into different categories called classes, depending on the speed of data transfer of the card. Here's a table that should help you understand this concept further:

Rating	Speed (MB/s)	SD Class
6x	0.9	n/a
10x	1.5	n/a
13x	2.0	2
26x	4.0	4
32x	4.8	4
40x	6.0	6
66x	10.0	6
100x	15.0	6
133x	20.0	6
150x	22.5	6
200x	30.0	6
266x	40.0	6
300x	45.0	6

The rating is the same speed rating that you see on the CD drives. 1x is equivalent to 150KBps. The rows highlighted in bold is the minimum speed for that particular class. Hence a Class 6 is faster than a Class 4 which is faster than a Class 2. Some devices have limitations on the speed of the card that can be used. To check the speed compatibility of your device, check the manual or the manufacturer's site as indicated above. So when you shop for a new card, you want to get the fastest version that is supported by your device. A slower card will mean more lag especially with higher capacities.

Now you've decided that an 8GB Class 6 MicroSD card is what you want for your phone. Now lets talk about the brands. There are a couple of good brands that you can trust your money with. Here are a couple- Kingston, Sandisk, Transcend, KingMax and Toshiba. I prefer Kingston SD cards because they are closer to the rated speeds, come with a life time warranty and are very reliable. If you need a MicroSD card of Class 6 variety, you'll have skip Kingston, as it doesn't produce them.

Lets look at the practical aspects now and see how the the SD/SDHC cards perform. I've used the same Nokia supplied OEM microSD to SD adapter for the tests. The tests were performed using H2testw v1.4. This free software is available here: http://www.heise.de/software/download/h2testw/50539. All the tests were performed for a 128MB file transfer. It must be noted that the read speeds are what you need to chiefly look at, since these are the speeds that influence access times on a phone/portable device.

512MB Nokia OEM MicroSD card:
Writing speed: 4.04 MByte/s
Reading speed: 13.1 MByte/s

1GB Toshiba MicroSD card:
Writing speed: 3.07 MByte/s
Reading speed: 13.1 MByte/s

2GB Nokia OEM MicroSD card:
Writing speed: 3.96 MByte/s
Reading speed: 9.84 MByte/s

4GB Transcend Class 6 rated MicroSD card:
Writing speed: 6.37 MByte/s
Reading speed: 14.1 MByte/s

8GB Kingston Class 4 rated MicroSD card:
Writing speed: 4.92 MByte/s
Reading speed: 13.7 MByte/s

As you can see the cards scored slightly above the minimum specs, with Kingston and both Nokia OEM cards performing much higher than their rated speeds.



If you have any suggestions or comments, please feel free to post them below. Until next time, Cheers!

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Labels: adapter, blog, card, drive, flash, memory, micro, mini, pen, read, reader, review, sd, shoot out, speed, sriram sridharan, sriraminhell, ssd, test, write