Re: main memory vs. storage memory on 128 meg samsung 1 730 ppc phone

Read access time for NOR flash is comparable to that of SDRAM (10-500 ns).
Write/erase time can be as high as minutes.

This type allows running code from it. BIOS in your PC uses it. If you ever
updated BIOS, you know it takes a while.

This type is not used for storage which is updated frequently (like more
than once a month).



Another type, NAND, is not directly addressable by CPU, its block accessible
only.

Access time to the block is in range of ms, data transfer rate (read and
write) can be from 100 Kbytes per second to tens of mb/s depending on
interface.

This type is commonly used in WM devices (and storage cards). Since code can
not run from it, OS would copy itself to RAM taking out some of it.



Yes, you can keep SQL Mobile/CE database on flash. That would preserve your
data in case of power failure, but slows SQL Mobile down.

There are some other issues with that. They've been discussed many times, so
please use search to find them.


Best regards,


Ilya

This posting is provided "AS IS" with no warranties, and confers no rights.

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"Kimberly" <jpierce2@xxxxxxxxxxxxx> wrote in message
news:%23UPI5D0nFHA.764@xxxxxxxxxxxxxxxxxxxxxxx
> Thanks Ilya!
>
>
>
> How fast is the main memory compared to the flash ram memory in
> nanoseconds? I'm just hoping that you know.
>
>
> Does Microsoft support SQL Mobile running on a fast SD Card or in built in
> flash memory? From a pros and cons point of view are their strong reasons
> not to do this?
>
>
> "Ilya Tumanov [MS]" <ilyatum@xxxxxxxxxxxxxxxxxxxx> wrote in message
> news:42fa7246$1@xxxxxxxxxxxxxxxxxxxxx
>> Like many Windows Mobile devices, i730 has 64 MB RAM. Some of it is used
>> by OS (5-10MB), rest is available.
>>
>> This available RAM is divided into two parts: storage memory which
>> stores files and program memory which is used by running applications.
>>
>> Should you put 10MB file to, say, \Windows, that would take out 10 MB of
>> available RAM.
>>
>> Think of this RAM as normal RAM on your desktop with part of it used for
>> RAM disk.
>>
>>
>>
>> In addition to RAM i730 (and other devices) has 128 MB Flash. Some of it
>> (~30-40 MB) is used to store OS.
>>
>> Rest is available as none-volatile storage. This storage looks like a
>> fake storage card to the system.
>>
>> Think of it as hard drive in your desktop.
>>
>>
>>
>> You could put your database to regular storage in RAM. It's fast, but
>> content will be lost should you run out of power.
>>
>> Also, it will reduce amount of program memory available to the
>> applications and OS.
>>
>>
>>
>> Fake storage card composed of flash is relatively slow, but it's NV.
>>
>> Also, storing stuff on it won't reduce precious RAM.
>>
>>
>>
>> If flash/RAM not enough, put in SD card for up to 2 GB (soon up to 4) of
>> NV storage.
>>
>>
>>
>> Best regards,
>>
>>
>>
>> Ilya
>>
>>
>>
>>
>>
>> This posting is provided "AS IS" with no warranties, and confers no
>> rights.
>>
>> *** Want to find answers instantly? Here's how... ***
>>
>> 1. Go to
>> http://groups-beta.google.com/group/microsoft.public.dotnet.framework.compactframework?hl=en
>> 2. Type your question in the text box near "Search this group" button.
>> 3. Hit "Search this group" button.
>> 4. Read answer(s).
>>
>> "Kimberly" <jpierce2@xxxxxxxxxxxxx> wrote in message
>> news:%23zsZssenFHA.3380@xxxxxxxxxxxxxxxxxxxxxxx
>>> Hi,
>>>
>>>
>>>
>>> Can someone tell me if this is a problem?
>>>
>>>
>>>
>>> We have been using Intermec devices with 128 Meg of memory. We are now
>>> using the new Samsung i730 with 128 Meg of memory. With the Intermec
>>> device most of the 128 Meg shows up on the settings main memory screen
>>> (screen with the adjustable bar for storage and program allocation).
>>> However, on the Samsung device which is also 128 meg device, only ~ 64
>>> meg shows on the main memory screen and the rest of the memory shows up
>>> on the storage card screen.
>>>
>>>
>>>
>>> The file system splits the 128 memory between the storage card folder
>>> and the main system folders. This looks like I can't have any file (i.e.
>>> database) or running application (app + database) that is greater than
>>> 64 Meg since the memory is split between two file systems. True? False?
>>>
>>>
>>>
>>> If I have a large application that has a large database > 64 Meg (app +
>>> database) will I have a problem with this device?
>>>
>>>
>>>
>>> Is the storage card memory the same speed as the main memory? Will
>>> applications and databases run just as well from the storage memory?
>>>
>>>
>>>
>>> Note: the all of the 128 Meg is built in, it is not memory from an SD
>>> card. The SD card slot is empty.
>>>
>>>
>>>
>>> Thanks for the help!
>>>
>>> Kimberly
>>>
>>>
>>>
>>>
>>
>>
>
>


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