Is a 12 MB/s microSD overkill for what the glamo driver does?

[Jim Colton]

If anyone cares this is the card I have coming and will speed test by using
dd(1) from the device to dev/null.  But as Tim said the bus speed the Glamo
willbe limiting.
http://www.memorysuppliers.com/atp-fmcs-atp-microsd-af4gud-ap-with-adapter.html
Jim

On Wed, Jul 30, 2008 at 3:07 PM, Jim Colton <jimcolt at gmail.com> wrote:

>
> Oh well, I should have bought a slower card.  At least it won't be a
> limiting factor.
> I'll compare speeds I get with your 3M bytes/sec. anyway.
>
> I was meaning 12 megabits /sec....
> By 12MB/s I was referencing what I see here
> http://en.wikipedia.org/wiki/Secure_Digital_card#Speeds
> 12MB/s is not in the table shown in that link however I am about to receive
> a 4G 80x or 12MB/s card in the mail .
>
> Thanks for your input Tim and Andy,
> Jim
>
>
> On Wed, Jul 30, 2008 at 1:05 PM, Andy Green <andy at openmoko.com> wrote:
>
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>> Somebody in the thread at some point said:
>> | Hey Tim,
>> |
>> | "no" it's not overkill or "no" is  the glamo driver  able to read that
>> fast?
>> | Are you involved with or knowledgeable of  how the glamo drive works?
>> | I'm not.
>>
>> I have that not very marketable distinction.
>>
>> We read from it at 16MHz / 4 bits, so not sure where this 12MBytes/sec
>> figure came from.  "Reading from SD Card" means collecting the block
>> data into Glamo RAM, after we have it there we have to copy it into CPU
>> RAM additionally.
>>
>> With some pending Glamo speedup patches in, effective Read speed is
>> around 3MBytes/sec measured by md5sum-ing a 40MByte test file.
>>
>> - -Andy
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