OESF Portables Forum
Everything Else => Sharp Zaurus => Model Specific Forums => Distros, Development, and Model Specific Forums => Archived Forums => C1000/3x00 Hardware => Topic started by: netog on November 22, 2005, 12:20:15 pm
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Hi.
I have an ordinary SD128 Lexar wich just works OK, but I want yo have a bigger storage.
I use my CF slot for: 256 MB card, a modem card and BT card... so I think I would be better to use SD for storage instead of CF, even when SD is slower.
Are those new SD high-speed compatible with the zaurus C1000? what is the bigger SD card you have used?
Thanks
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Hi.
I have an ordinary SD128 Lexar wich just works OK, but I want yo have a bigger storage.
I use my CF slot for: 256 MB card, a modem card and BT card... so I think I would be better to use SD for storage instead of CF, even when SD is slower.
Are those new SD high-speed compatible with the zaurus C1000? what is the bigger SD card you have used?
Thanks
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It seems, that the largest you can use is 1 GB for an SD card. And I would think that you can take any speed (as long as less than 1 GB) and they should all work.
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Please bear in mind that my C3100 has not yet arrived, but speaking from general experience with several other models I'll inject some hopefully appropriate info. I've already picked the brain of everyone I could get to respond to me about this subject (I wanted to know BEFORE I bought my 3100) and I've been assured that the SD slot and it's implementation is exactly the same as the ones in the rest of the clamshell line and the SL-6000 series.
I spent a HUGE amount of money (for me anyway) getting a Lexar 1gb 32x SD card about a year ago hoping that the extra speed would help because I noticed my SD slot has never been as fast as my CF even when using the same "speed" cards.
It turns out that it DID speed my read throughput up but only about 5% to what I was getting with my "4x" card I owned previously and my seek times remained unchanged. What DID somewhat signifigantly was my write throughput, increasing by almost 20%.
Afterwards I learned that all of the sdcard slots in every one of the Z models are crippled and run in MMC compatibility mode. As MMC is pronouncedly slower this shackles our performance ability when using high end sdcards. This is also one of the reasons that even on the new models that technically could have used the newer sdio WiFi modules these new devices don't work for us- and may never work since the drivers for the sdio technology is proprietary and not open-source.
Anyway what this all boils down to is this:
- MMC is cheaper but slower most of the time for our Z's.
- SDcards are usually more expensive than the MMC's but also can be about twice as fast or more (than the MMC's.)
- You will only see performance gains when using up to about a 10x rated SDcard- after that the speed benefit drops to near zero when dealing with read latency, write latency, and read throughput.
- Write speeds CAN be fairly substantially increased when using faster SDcards but unless you are using the sdcard for a swapdrive/swapfile you probably WON'T enjoy or even notice that speed difference because 90%+ of what we do in normal use does not incur much writing to the drive.
Please know that I cannot confirm that the write speed boost that I experienced when upgrading to the Lexar 32x SDcard would apply to any other brand/speed of SDcard. It's possible that this benefit is only had because of somehow Lexar manages the memory architecture. I'd like to experiment in this but cannot afford to purchase a dozen 1gb sticks of various brands etc. =(
I DO know that as of a couple of weeks ago, there was no known maker of SDcards larger than 1GB that work correctly with any Zaurus. That includes Lexar. I think the question has been asked and remains as to whether a MMC 2gb drive would work correctly, but no one has reported on that issue yet. Someone porbably will soon as the MMC cards are MUUUUCH cheaper at the 2gb level than the SDcards are. (Kingmax are almost silly cheap.)
My friend, I hope this helps you some.
God Bless,
-NeuroShock
Hi.
I have an ordinary SD128 Lexar wich just works OK, but I want yo have a bigger storage.
I use my CF slot for: 256 MB card, a modem card and BT card... so I think I would be better to use SD for storage instead of CF, even when SD is slower.
Are those new SD high-speed compatible with the zaurus C1000? what is the bigger SD card you have used?
Thanks
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If my memory serves me correctly, the *hardware* driver for the SD is on the zaurus, while the driver is on the card for CFs. This is why the zaurus has 1GB limitation on SDs, but we have not seen the capacity limit on the CFs. Sharp needs to update its hardware driver on the zaurus for us to enjoy higher capacities.
I can't remember where the original post was, but maybe somebody else can support or correct me.
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@ bluedevils : I read this somewher too.
There have been reported a lot of problems with sandisk SD cards. Beware.
I personally broke two 1Gb sandisk SD's in 2 months or so.
Then I bought the sandisk Ultra II 1Gb, and haven't had any troubles ever since. It has been in my C860 for almost a year and is in my C3100 now.
I also tried it's 2Gb brother (or sister ?), but no go.
Chero.
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The new MMC v4 standard is supposed to be quite a bit quicker that SD cards, but to date i dont know of any cards or devices that support it, personally i prefer the mmc spec as it dosent have the DRM stuff built into the card, the only problem is thier is no IO, but as there is no IO on the zaurus i dont think this matter much
the good thing about high speed cards is if you are transfering data between the zaurus and the pc as it tends to be alot faster than the usb port, also you tend to get a better waranty on the high speed cards
under some circimstances SD cards can be faster for OVERALLL system performance than CF cards, for eg playing moives (this has been documented in the windows ce pda's with CF cards as well and intel has a white paper on the subject)