micro SD "HC class 4" card

Other Hardware Storage
1

Hi all,
Has anyone test the SD card reader that comes included with the Ethernet Shield, in combination with one of those "HC class 4" micro SD cards?
Thanks.

2

Here are the results for a Class 4 Kingston 4GB HC card with the Ethernet shield on an UNO.

http://www.amazon.com/Kingston-microSDHC-Memory-SDC4-4GBET/dp/B00200K1TI

For SdInfo:

init time: 990 ms

Card type: SDHC

Manufacturer ID: 0X41
OEM ID: 42
Product: SD4GB
Version: 2.0
Serial number: 2711490139
Manufacturing date: 3/2009

cardSize: 7745536 (512 byte blocks)
flashEraseSize: 128 blocks
eraseSingleBlock: true

SD Partition Table
part,boot,type,start,length
1,0X0,0XB,8192,7737344
2,0X0,0X0,0,0
3,0X0,0X0,0,0
4,0X0,0X0,0,0

Volume is FAT32
blocksPerCluster: 64
clusterCount: 120768
freeClusters: 120539
fatStartBlock: 14496
fatCount: 2
blocksPerFat: 944
rootDirStart: 2
dataStartBlock: 16384

Here is the SdFat bench result (Note write is very slow):

Type is FAT32
File size 5MB
Buffer size 100 bytes
Starting write test. Please wait up to a minute
Write 65.34 KB/sec
Maximum latency: 234516 usec, Minimum Latency: 84 usec, Avg Latency: 1521 usec

Starting read test. Please wait up to a minute
Read 278.91 KB/sec
Maximum latency: 3588 usec, Minimum Latency: 80 usec, Avg Latency: 353 usec

Here are the bench results for a Class 10 Amazon 4GB card Amazon.com

Type is FAT32
File size 5MB
Buffer size 100 bytes
Starting write test. Please wait up to a minute
Write 169.04 KB/sec
Maximum latency: 189888 usec, Minimum Latency: 84 usec, Avg Latency: 586 usec

Starting read test. Please wait up to a minute
Read 288.37 KB/sec
Maximum latency: 3136 usec, Minimum Latency: 80 usec, Avg Latency: 341 usec

3

Thanks! Then I guess I will go for the 8GB Kingston Class 4 micro SD HC + SD adapter.

I was kind of afraid that the "new/modern" micro SD may not be compatible with the Ethernet Shield's card reader.