Changes between Version 4 and Version 5 of WAM/CreateCF


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Timestamp:
Nov 25, 2014, 5:56:46 PM (6 years ago)
Author:
bz
Comment:

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  • WAM/CreateCF

    v4 v5  
    1212   Barrett Technology uses the following: [[br]][[http://www.digikey.com/product-detail/en/SFCF8192H4BK4SA-I-QT-553-SMA/1052-1012-ND/2620346| 8GB SLC-flash CF Card]][[br]]
    1313   The installation requires __1GB RAM__[[br]]Barrett Technology uses the following:[[br]][[http://www.newegg.com/Product/Product.aspx?Item=N82E16820145068| PC/104 1GB RAM]]
     14
     15== Important Note about Flash Memory Types ==
     16It can be challenging to find a CF card that is made from SLC-based (Single Layer Cell) flash instead of the much more common (and cheaper) MLC-based (Multi Layer Cell) flash. The cards we use (from SwissBit) are between 100 to 200 dollars each. If you are not paying over $100, you are probably not getting an SLC device. SLC is important because we are using the CF card as a hard disk with an ext4 journaling filesystem. MLC flash is not durable enough to operate for more than a few months in this capacity, but SLC will last many years before it wears out. It is nearly impossible to get most flash manufacturers to divulge which technology they use. You will need to call their engineers directly. We used to use SanDisk Extreme cards (originally marketed as SLC). We had a relationship with a SanDisk engineer who informed us that they "secretly" switched from SLC to MLC in their high-end CF products without even changing the part number. Plus, you need to watch out for fakes - even if you find a product that is based on SLC, you need to make sure you are getting it straight from the manufacturer, not a reseller. Even Amazon, Walmart, and NewEgg have been caught selling fakes... and they still are.
     17
     18On the other hand, if you are willing to accept the risk of a CF disk failure within a year, and if you make regular backups of your software, then go ahead and buy anything you want!
    1419
    1520== Install Barrett Provided CF Image ==