How to test microSD speed in G1?

[RegGuheert]

One of the first things I want to do when I first receive my G1 is to perform a test to find out if there is any *real* difference in user experience using a class 2 microSD card versus a class 6 card. Why? Because I want to decide if I should go ahead and purchase a 16 GB card for our 2nd G1, knowing they are only class 2 right now.

Materials available for experiment:
G1 phone (hopefully soon!)
Sandisk 4GB Class 2 microSD (which is currently in my Blackberry)
A-Data 8GB Class 6 microSD (sitting here waiting for the G1)

Experiments to try (with each card):

1) Take a photo and see how long it takes to store the picture.
2) ???

I don't know what else to try! Please suggest experiments that I can perform to time the results. I want all the experiments to be done *within* the G1 (not in an computer) and to not be influenced by network speed, so that it will be clear whether there is any difference in user experience using the different speed devices. Of course I will tabulate all results here!

TIA for your help!

Reg

[dkw0417]

I was thinking of doing the same type of thing. I have a 8gb class 2 card and just got a 8gb class 8.

[senor360]

The newly released 16gb from Sandisk is what I was thinking about buying. Their website though shows it as a class 2 memory card. Should I hold out and wait for them to release a higher class # before buying? How much of a difference do the different class numbers show in performance?

[Stewartwi]

You could try putting some large music files or a video on to the SD card and then see how long it takes between the two cards to start up pulling from the SD card to the phones flash memory.

[DesignDawg]

The newly released 16gb from Sandisk is what I was thinking about buying. Their website though shows it as a class 2 memory card. Should I hold out and wait for them to release a higher class # before buying? How much of a difference do the different class numbers show in performance?

The class #s correspond to MB/s transfer speeds.

SDHC



8GB SDHC cards
SDHC (Secure Digital High Capacity, SD 2.0) is an extension of the SD standard that appeared in June 2006.[16] SDHC allows standard-compliant capacities in excess of 2 GB. SDHC cards are often formatted with the FAT32 file system.[17] It uses the same form factor as SD, but the SD 2.0 standard in SDHC uses a different memory addressing method (sector addressing vs byte addressing), thus theoretically reaching a maximum capacity of up to 2 TB (2048 GB). However the SD Card association have artificially defined the maximum limit of SDHC capacity to 32 GB. SDHC cards only work in SDHC compatible devices, but standard SD cards work in both SD and SDHC devices. The SDHC trademark is licensed to ensure compatibility.[18]
SDHC cards have SD Speed Class Ratings defined by the SD Association. The SD Speed Class Ratings specify the following minimum write speeds based on "the best fragmented state where no memory unit is occupied":[19]
Class 2: 2 MB/s
Class 4: 4 MB/s
Class 6: 6 MB/s
SDHC cards will often also advertise a maximum speed (such as 133x or 150x) in addition to this minimum Speed Class Rating. See section Speeds above for a further explanation. One critical difference between the Speed Class and the maximum speed ratings is the ability of the host device to query the SD card for the speed class and determine the best location to store data that meets the performance required. "Maximum speed" ratings are quoted by the manufacturers but unverified by any independent evaluation process.

[RegGuheert]

Thanks for all the feedback. Please keep it coming!

The following is something I've been wondering about:

SDHC cards will often also advertise a maximum speed (such as 133x or 150x) in addition to this minimum Speed Class Rating. See section Speeds above for a further explanation. One critical difference between the Speed Class and the maximum speed ratings is the ability of the host device to query the SD card for the speed class and determine the best location to store data that meets the performance required. "Maximum speed" ratings are quoted by the manufacturers but unverified by any independent evaluation process.

When I received my microSD from A-Data, I noticed that while the minimum rating is Class 6, the package also states "Read/Write: 22/10 MB/S".

Anyway, as stated in a previous thread, I've had some *horrible* experience with flash speeds in my old HP iPaq. That thing has a similar processor speed to the G1, but large transfers between a CompactFlash and an SD card installed in the device are *painfully* slow (100 MB took 30 minutes, IIRC!). I suspect the limitation was either Windows Mobile or the architecture of the device, but the speed definitely affected my user experience. Both of the cards involved in that transfer were reasonably fast within a camera or a laptop computer. Hence my interest to see how the G1 does with microSD.

Reg

[i<3g1]

One of the first things I want to do when I first receive my G1 is to perform a test to find out if there is any *real* difference in user experience using a class 2 microSD card versus a class 6 card. Why? Because I want to decide if I should go ahead and purchase a 16 GB card for our 2nd G1, knowing they are only class 2 right now.

Materials available for experiment:
G1 phone (hopefully soon!)
Sandisk 4GB Class 2 microSD (which is currently in my Blackberry)
A-Data 8GB Class 6 microSD (sitting here waiting for the G1)

Experiments to try (with each card):

1) Take a photo and see how long it takes to store the picture.
2) ???

I don't know what else to try! Please suggest experiments that I can perform to time the results. I want all the experiments to be done *within* the G1 (not in an computer) and to not be influenced by network speed, so that it will be clear whether there is any difference in user experience using the different speed devices. Of course I will tabulate all results here!

TIA for your help!

Reg

I've never owned a Blackberry device so I don't know if you can do these tests but...

1) load up some MP3's and see how long it takes to load tracks, and skip to the next track, go back etc.

2) Load and play a movie off of the sd card and see if there is any lag or if the movie plays cleanly without skipping or pausing to buffer. (This also has to do with the device's hardware, so I'm not sure how much the sd card speed affects this.

[RegGuheert]

Well, I decided to not do testing of the microSD cards within the G1. Instead my son found a Windows program called CrystalDiskMark which is used to test storage device performance for differing file sizes. It looks like it is optimized to evaluate whether Flash memory is suitable for use with Windows Vista ReadyBoost.

Here are some results (All speeds in MB/s):

----------------------------| Sequential |512 kB Files| 4 kB Files |
---------Device------------| Read|Write |Read|Write |Read |Write|
SanDisk 4GB Class 2 microSD|10.64|5.056|10.47|1.959|3.176|0.028|
A-Data 8GB Class 6 microSD |15.69|7.292|15.48|1.870|3.784|0.024|
A-DATA 2GB SD ----------- |10.62|5.874|5.529|3.700|2.898|0.164|
WD 250GB 5400RPM 2.5" HD |38.94|33.19|18.26|25.30|0.251|1.138|

(Sorry for the crude table. I wasn't able to get table tags to work.) The last two entries are there for reference only.

My conclusion is that the A-Data Class 6 device isn't THAT much faster than the SanDisk Class 2 device. I'm not sure it would make any difference for the G1 application.

Thoughts?

Reg

[Ripsphone]

I just copied 4g of music from iTunes to my G1. I have a Patriot 8g class 4 that I bought for $29. I took about 15 minutes to transfer it all. Kind of slow but I wont be transferring stuff back and forth alot.