[j-nsp] Sandisk Extreme III 1G CF card compatibility

Richard A Steenbergen ras at e-gerbil.net
Mon May 5 16:23:46 EDT 2008

On Mon, May 05, 2008 at 01:14:41PM -0400, Dave Diller wrote:
> This is an FYI, and a separate issue form Pekka's discovery that these  
> faster cards can hog CPU when being written.
> It turns out that some SanDisk Extreme III 1G cards are Juniper  
> friendly, and others are not.  We purchased three at the same time  
> from the same CompUSA.  Of the three, two do not work and the third  
> one is fine. The symptom is that the non-functional ones time out and  
> you can't install anything on them (but 6509's are fine with them, so  
> they'll be redeployed there ;-):

I believe the distinction is that some (usually modern high-speed units, 
or especially cheap regular units) CF cards do not support PIO mode, and 
assume that anyone in their right mind buying a 1G CF is going to plug it 
into a device which supports UDMA, and high speed UDMA at that.

Unfortunately neither old Juniper RE's nor Cisco SUP720s support UDMA 
(which, incidentally, contributes about 2 minutes to a 6509's slow-as-hell 
boot time running modern code) on their ATA CF controllers. You're best 
off getting a regular classic SanDisk with PIO support, there are no 
benefits to be had by putting nice CFs into old and crappy hosts. The 
ironic thing is that I think the CONTROLLER on the old Juniper RE's 
supports UDMA, but there aren't traces for it on the CF adapter. :)

Richard A Steenbergen <ras at e-gerbil.net>       http://www.e-gerbil.net/ras
GPG Key ID: 0xF8B12CBC (7535 7F59 8204 ED1F CC1C 53AF 4C41 5ECA F8B1 2CBC)

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