Re: microSDHC class 4 or class 6?
On, 2008-07-18 kello 15:14 -0500, Hans L kirjoitti: On Fri, Jul 18, 2008 at 2:26 PM, Andrew Burgess [EMAIL PROTECTED] wrote: Can the Freerunner make use of the class 6 speed? If not I'll go for the max size. According to http://en.wikipedia.org/wiki/Secure_Digital_card#SDHC Class 4 supports a minimum write speed of 4MB/s, and 6MB/s for class 6. Correct and sorry for not defining my terms Not sure how fast the Freerunner is capable of writing though. That's my real question According to raster the glamo (which is also the SD card controller) bus speed is 7.3m/s (I presume from context he means megabytes). This with the cpu doing nothing else besides transferring data to or from the card; thus in practice I don't think the class 4/6 distinction is going to matter much on the FR. I would go for the size (and did, with my 8 GB I saw a post (here?) about the performance of different filesystems and I recall seeing flash performance numbers of 9MB/s. Maybe that was read speed but 9 7... But, I haven't experimented with the different classes, so grains of salt OK, I'll volunteer. I just ordered a 4GB class 6 and an 8GB class 4 from Newegg, both Transcend brand. I'll post results next week. Also, there were some wait state tweaks posted on the kernel list to speedup glamo access. They were /sys controllable so I'll throw them into the mix. My little contribution :-) Andrew Burgess ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: microSDHC class 4 or class 6?
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Somebody in the thread at some point said: | Not sure how fast the Freerunner is capable of writing though. | | That's my real question It defaults to 16MHz SD_CLK, but you can mess with it now, see http://git.openmoko.org/?p=kernel.git;a=commitdiff;h=ef2376d29e996d9d21a9e5798cb88aa73f734c83 - -Andy -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.9 (GNU/Linux) Comment: Using GnuPG with Fedora - http://enigmail.mozdev.org iEYEARECAAYFAkiCD14ACgkQOjLpvpq7dMolyACfTsidyeAjwczXpJcBafuRUKfs R0QAoIapS1uYAd7ukLMAso0F+WDtt4t2 =SqjQ -END PGP SIGNATURE- ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
microSDHC class 4 or class 6?
I've been able to find 4GB class 6 microSDHC cards and 8GB class 4 cards. Can the Freerunner make use of the class 6 speed? If not I'll go for the max size. ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: microSDHC class 4 or class 6?
On Fri, Jul 18, 2008 at 2:26 PM, Andrew Burgess [EMAIL PROTECTED] wrote: I've been able to find 4GB class 6 microSDHC cards and 8GB class 4 cards. Can the Freerunner make use of the class 6 speed? If not I'll go for the max size. According to http://en.wikipedia.org/wiki/Secure_Digital_card#SDHC Class 4 supports a minimum write speed of 4MB/s, and 6MB/s for class 6. Not sure how fast the Freerunner is capable of writing though. Hans ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
Re: microSDHC class 4 or class 6?
pe, 2008-07-18 kello 15:14 -0500, Hans L kirjoitti: On Fri, Jul 18, 2008 at 2:26 PM, Andrew Burgess [EMAIL PROTECTED] wrote: Can the Freerunner make use of the class 6 speed? If not I'll go for the max size. According to http://en.wikipedia.org/wiki/Secure_Digital_card#SDHC Class 4 supports a minimum write speed of 4MB/s, and 6MB/s for class 6. Not sure how fast the Freerunner is capable of writing though. According to raster¹ the glamo (which is also the SD card controller) bus speed is 7.3m/s (I presume from context he means megabytes). This with the cpu doing nothing else besides transferring data to or from the card; thus in practice I don't think the class 4/6 distinction is going to matter much on the FR. I would go for the size (and did, with my 8 GB class 4 card). But, I haven't experimented with the different classes, so grains of salt and all. ¹ http://lists.openmoko.org/pipermail/community/2008-April/016518.html -- Mikko Rauhala - [EMAIL PROTECTED] - URL:http://www.iki.fi/mjr/ Transhumanist - WTA member - URL:http://www.transhumanism.org/ Singularitarian - SIAI supporter - URL:http://www.singinst.org/ ___ Openmoko community mailing list community@lists.openmoko.org http://lists.openmoko.org/mailman/listinfo/community
