[DuoList] CompactFlash: is 8MB/sec read 1.2MB/sec write fast enough?

[Gene Osburn]

> Greetings. Whoa! Newegg.com has 1GB Viking CompactFlash cards for $40  
> (after $10 mail-in rebate) <http://www.newegg.com/Product/Product.asp? 
> Item=N82E16820160138>! The product description says "high speed" but  
> doesn't quantify. I went to Viking's website and got the specs at 8MB/ 
> sec read and 1.2MB/sec write. How does this translate into the 40X, 80X,  
> 150X ratings I see on some cards? Is this fast enough for use as a  
> boot-drive in my PB2400c?

"Fast" is a relative term here.  Check out Dan Kinght's (list sponsor)  
article on the subject from three years ago:
http://www.lowendmac.com/macdan/02/1114dk.html

Virtually any 1 GB CF card will be "fast enough" for boot drive use and  
you'll get some benefit from it, but the faster the better (up to a  
certain point, I suppose -- I don't claim to know where that point  
is...).  For comparison consider that the Old World PCI Power Macs had a  
10 MB/sec internal SCSI bus, and this is considered a bottleneck when  
trying to maximize performance.  10 MB/sec is a definite step up for the  
PowerBook 1400-3400's though, so a CF card that "fast" is what I'd look  
for....

1X=150KBps (Kilobytes per second), so my fuzzy math leads to an estimate  
of about 50X for that Viking card's 8 MB/sec read rate.  The PCMCIA specs  
top out at 20 MB/sec so I'd be tempted to go for at least a 70X, which  
should transfer date somehere in the 10 MB/sec range.  I'd also search for  
cards with a faster write speed than 1.2 MB/sec (I'd want *at least*  
double that, if not better).  I'm only somewhat informed about flash  
memory media, but I'd guess that the quality stuff would have better  
read-to-write speed ratios.


-- 
Gene Osburn
Friends don't let friends do Windows

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