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On Mon, Jul 27, 2009 at 10:43 AM, Florian Philipp < |
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lists@f_philipp.fastmail.net> wrote: |
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> Grant schrieb: |
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> |
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<snip> |
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> >> You don't need to buy SSD "drives" - instead you could use CF cards and |
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> a |
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> >> cheap adaptor. These are commensurate in capacity & cost with USB flash |
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> >> drives (4gig, maybe 16gig?), but CF cards "talk EIDE" and you can get |
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> cheap |
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> >> pin-convertors allowing you to connect them to EIDE cables and treat |
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> them |
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> >> like a hard-drive. |
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> > |
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> > Aren't CF cards much slower than SSD drives and HD drives? |
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> > |
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> |
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<snip> |
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> |
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> If you really need to write to the CFDisk, make sure to buy one with DMA |
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> support (and no, the label "super fast" which is regularly found on |
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> these things does not necessarily mean that it supports DMA). |
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One thing to watch out for if you do go the CF/DMA route - be careful what |
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CF<->IDE/SATA adapter you buy - in an embedded control system project I |
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worked on a few years ago, we went CF + adapter for the primary OS driver, |
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got a super-fast 4GB CF card, and couldn't use the speed of it at all, |
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because the cheapo CF adapter we got was so electrically noisy across the |
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physical adapter pins, that DMA reads/writes would fail, and the speed would |
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get auto-reduced to PIO. Very, very, very annoying. If you get a CF adapter, |
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make sure to spend the extra $5-20 (or however much, I haven't priced in |
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quite a while) to get something that will be compatible with the transfer |
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speeds that you are wanting to use. |
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-James |
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