06-04-2013 06:48 PM - edited 06-04-2013 06:49 PM
the transfer rate drops a lot when the block size >= 1024KB
no matter format the sd card to fat32, ntfs or exfat
128KB : R77MB, W34MB
256KB : R83MB, W42MB
512KB : R85MB, W52MB
1024KB: R85MB, W21MB
2048KB: R85MB, W21MB
4096KB: R85MB, W21MB
8192KB: R85MB, W21MB
does anyone has the same problem or the solution?
hdd: crucial m4 128GB ssd
reader: Ricoh PCIe SD reader (x220 built-in)
sd card: toshiba exceria type 2 32GB (max. R95MB, W60MB)
OS: windows 7 ultimate x64
06-05-2013 03:35 AM
I found the specs for the Toshiba UHS Exceria SD Cards here on Toshiba's web site.
Do you have another card reader or SDXC card you can test with to help determine if the problem is with the card or the card reader?
Does it make a difference if you disable (or even uninstall, temporarily, for troubleshooting purposes) your security software?
06-05-2013 04:08 AM - edited 06-05-2013 04:14 AM
thx for reply.
i tested it with the clean windows recovery image (no antivirus or anything else)
also, i used a usb 2.0 reader to test the sd card. the write speed can achieve 30MB.
i thought this may be a common issue of the built-in reader.
because i found another case in Taiwan with the same card (toshiba exceira type 2 32GB + x220) and the issue also exists when i used another model sd card from toshiba (exceria type HD microSD 32GB, R95/W30)
Taiwan case : sandisk extreme pro (45MB) -> R43/W37
toshiba exceria type 2 (R95/W60) -> R85/W20
futhermore, i tried to turn on/off windows file write cahce which is useless.
06-06-2013 03:52 AM - edited 06-06-2013 03:55 AM
my case : x220 + toshiba exceira SD
another case of x230 + toshiba exceria SD card was found
Taiwan case : x220 + toshiba exceira type 2
Normal speed of this SD card:
06-06-2013 03:59 AM
To help troubleshoot things further, can you try a different operating system, such as by booting from a Linux Live CD/USB disc image? That can help us figure out whether we are dealing with a software or a hardware issue.
06-06-2013 06:01 AM - last edited on 06-06-2013 06:26 AM by andyP
06-06-2013 06:50 AM
x220 + toshiba exceria type HD microSDHC 32GB
x220 + toshiba exceria type HD SDHC 16GB
i thought the sd reader of x220 doesn't support UHS-1 well. The transfer rate drops when block size >=1024KB with three different card (all toshiba exceria series: Type 2 SDHC 32GB R95/W60, Type HD SDHC 16GB and Type HD microSDHC 32GB)