<html><body><div>Adrian,</div>
<div>what kernel and u-boot version are you using?</div>
<div> </div>
<div>Thanks,</div>
<div>Rob<BR><BR></div>
<BLOCKQUOTE style="PADDING-LEFT: 8px; MARGIN-LEFT: 8px; BORDER-LEFT: blue 2px solid" webmail="1">-------- Original Message --------<BR>Subject: Re: [Gumstix-users] microSDHC support<BR>From: "adrian cockcroft" <adrian.cockcroft@...: Thu, November 08, 2007 11:58 am<BR>To: "General mailing list for gumstix users."<BR><gumstix-users@... has 8 pins, same as microSD, it changes the protocol to be<BR>block addressed rather than byte addressed I think to get the extra<BR>space, and then higher clock rates for the extra speed.<BR><BR>What I see is that the microSDHC card is much faster on a USB2.0 card<BR>reader, but runs at about the same speed as microSD on the Gumstix.<BR>There seems to be a 2MByte/s limit for reads and a 1MByte/s limit for<BR>writes. I suspect that writes may be being read back to verify?<BR><BR>I'm still benchmarking all the cases.<BR><BR>Adrian<BR><BR>On 11/5/07, Craig Hughes <<A onclick="Popup.composeWindow('pcompose.php?sendto=craig%40gumstix.com'); return false;" href="http://email.secureserver.net/pcompose.php?aEmlPart=0&type=reply&folder=INBOX&uid=460#Compose">craig<B></B>@gumstix.com</A>> wrote:<BR>> On Nov 4, 2007, at 9:58 PM, adrian cockcroft wrote:<BR>><BR>> > I got a Sandisk 6GB microSDHC C4 from Amazon, including USB adaptor it<BR>> > cost $75 and it *does* work on the Gumstix. Popped it in booted up and<BR>> > got a 6GB filesystem on /mnt/mmc no problem. The C4 rating is supposed<BR>> > to mean 4X speed of a regular SD card, about 4 MBytes/s. The 4GB<BR>> > microSDHC cards I could find were C2 speed, and I think there are some<BR>> > C6 cards around, but I couldn't find them on Amazon. The actual speed<BR>> > I got was a bit faster than the 2GB microSD, I'm still benchmarking,<BR>> > but its not 4x the speed at this point.<BR>><BR>> I think the "4x" speed comes from a combination of higher clock rate<BR>> on the bus and (possibly) more pins for the data path. Does your new<BR>> microSDHC card have 8 pins, or more than 8? istr that there's some 8-<BR>> bit cards now. The verdex SD controller's clock speed of course<BR>> won't have magically changed by plugging in a new slave card to it,<BR>> and the data path will handshake to 4-bits only, since that's all the<BR>> verdex supports. It could be though that your old card wasn't maxing<BR>> out the verdex's controller, but now the new card is. Do you see a<BR>> 4x speed difference when using it in the USB card reader from a PC?<BR>> Of course, it possible the card reader doesn't support fast wide<BR>> access too...<BR>><BR>> C<BR>><BR>> -------------------------------------------------------------------------<BR>> This SF.net email is sponsored by: Splunk Inc.<BR>> Still grepping through log files to find problems? Stop.<BR>> Now Search log events and configuration files using AJAX and a browser.<BR>> Download your FREE copy of Splunk now >> <A href="http://get.splunk.com/" target=_blank>http://get.splunk.com/</A><BR>> _______________________________________________<BR>> gumstix-users mailing list<BR>> <A onclick="Popup.composeWindow('pcompose.php?sendto=gumstix-users%40lists.sourceforge.net'); return false;" href="http://email.secureserver.net/pcompose.php?aEmlPart=0&type=reply&folder=INBOX&uid=460#Compose">gumstix-users<B></B>@lists.sourceforge.net</A><BR>> <A href="https://lists.sourceforge.net/lists/listinfo/gumstix-users" target=_blank>https://lists.sourceforge.net/lists/listinfo/gumstix-users</A><BR>><BR><BR>-------------------------------------------------------------------------<BR>This SF.net email is sponsored by: Splunk Inc.<BR>Still grepping through log files to find problems? Stop.<BR>Now Search log events and configuration files using AJAX and a browser.<BR>Download your FREE copy of Splunk now >> <A href="http://get.splunk.com/" target=_blank>http://get.splunk.com/</A><BR>_______________________________________________<BR>gumstix-users mailing list<BR><A onclick="Popup.composeWindow('pcompose.php?sendto=gumstix-users%40lists.sourceforge.net'); return false;" href="http://email.secureserver.net/pcompose.php?aEmlPart=0&type=reply&folder=INBOX&uid=460#Compose">gumstix-users<B></B>@lists.sourceforge.net</A><BR><A href="https://lists.sourceforge.net/lists/listinfo/gumstix-users" target=_blank>https://lists.sourceforge.net/lists/listinfo/gumstix-users</A><BR></BLOCKQUOTE></body></html>
|