OESF Portables Forum
Everything Else => Sharp Zaurus => Model Specific Forums => Distros, Development, and Model Specific Forums => Archived Forums => C1000/3x00 Hardware => Topic started by: bcom75 on May 10, 2005, 08:31:45 pm
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Hi all,
I was reading some posts regarding Secure Digital transfer speeds on 760/860 devices and the fact that they were way lower than advertised speeds (45X, 60X) on faster cards. Some pointed out to PXA255 architecture as being the cause.
question is, is it worth to get Ultra II (66x or 60X) SD cards for a C1000, with the PXA270 architecture, or would it be enough to get lower speed cards, as we should not expect speeds in excess of 1500 KB/sec ?
many thanks!
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The reason on the cxx0 machines - and the same on the cx000 machines i think - is that the sd driver is actually a MMC driver and that for a sd driver one has to join the sd association and sign a nda...
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What about CF? I'm interested in buying a large SD or CF to watch videos and music while i´m out. Would it also help save battery life of my C3k?
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Though I do not know for the 3000/1000, the earlier Zs only utilized two of the four data channels in the SD implementation. AFAIK CF cards are not hindered and are recommended if speed is important. With that said, I can play mp3s and most video from SD without problem.
I'm pretty sure there is at least one person who did test between a normal SD and the higher speed version.
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I'm pretty sure there is at least one person who did test between a normal SD and the higher speed version.
There are lots of speed tests done with the card readers. You can google these.
You never know about the real speeds of cards. Some 40X are faster than some 60X. Example Transcend 45X is faster than some 60X SD cards.
Kingston's Ultimate Secure Digital serie should be very fast.
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In conclusion: You can and should buy a "normal speed" SD card. The speed is actually limited by the processor itself... No idea if SD speed has been improved in the CXXXX models.
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@Bluedevils: actually i think you mean 1 bit, the SD card spec only has 3 modes, SPI,1Bit and 4Bit
the pxa270 is the first pxa processor to support the 4bit mode, not sure is sharp supported it or not but if they did then the maximum read/write speed fot the sd card is 12.5MB/s (25Mhz @ 4bit)
with the new 166x speed cards you should not see any performance gain as there is no device that i know of that can support the 166x speed (i belive it was added in the sd card 2.0 spec)
so to add everything up and fill in some points - pxa250 = 1bit mode,2.5MB/s max pxa270 = 4bit mode, 12.5MB/s max (if sharp programed thier drivers for it), The only time you reach that speed is when writing multiple pages at the same time
the new sd kernel drivers ethier support 4 bit or has hooks for it (2.6 series, see the status of the port at http://www.orca.cx/zaurus/) (http://www.orca.cx/zaurus/))
basically i wouldnt bother unless you have a 1GB or 2 GB card and are transfering files between your pc and pda
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with the new 166x speed cards you should not see any performance gain as there is no device that i know of that can support the 166x speed (i belive it was added in the sd card 2.0 spec)
Can Zaurus SL-Cxx00 handle these new SDs?
Example CVS-Direct.de - RiDATA 2GB 150X SD (http://www.csv-direct.de/scripts/banner2.php4?SEARCHSTRING=A1710669)
Anyone tested memory like this?
I read that some machines can't run these ~150X class SDs at all.
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with the new 166x speed cards you should not see any performance gain as there is no device that i know of that can support the 166x speed (i belive it was added in the sd card 2.0 spec)
Can Zaurus SL-Cxx00 handle these new SDs?
Example CVS-Direct.de - RiDATA 2GB 150X SD (http://www.csv-direct.de/scripts/banner2.php4?SEARCHSTRING=A1710669)
Anyone tested memory like this?
I read that some machines can't run these ~150X class SDs at all.
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Hi,
this card is not running with the normal Sharprom, cacko 1.23 and pdaxrom (C7xx,C1xxx,c3xxx).
I don't know what's the problem, but I think it has something to do with the timings or the Size.
1GB cards are supported fine.
When you use the card in an other cardreader with the USB-Host (C1xxx,C3xxx), it works.
You'll have the same Problem with notebook which has an integrated cardreader based on the Texas Instruments PCIxx21 chipset (like Joybook 7000). Notebooks with winbond chipset works fine (like HP Omnibook XT1500).
My hope is a new kernel driver for the SD/MMC device.
cu
curiosity