Re: Repeater and the CFC

[hutton <hutton@pathcom.com>]

Try This and see what happens!

"Damon Langlois (Electrix)" wrote:

> http://www.simpletech.com/wtb/wtb_irt.htm
>
> Respect,
>
> Damon Langlois
> Creative Director
> Electrix
> Tel (250) 544-4091 Fax (250) 544-4100
> http://www.electrixpro.com
>
> -----Original Message-----
> From: hutton [mailto:hutton@pathcom.com]
> Sent: Monday, August 27, 2001 4:54 PM
> To: Loopers-Delight@loopers-delight.com
> Subject: Re: Repeater and the CFC
>
> Want a laugh? ........ ask this man where you can purchase a 128mb
> SimpleTech
> CFC in Canada ....... Listen to his company's  "Answer" ...... Note 
>,,,,, it
> is
> a Canadian company!
>
> "Damon Langlois (Electrix)" wrote:
>
> > >I saw your list of recommended CFC cards, included the SanDisk brand, 
>but
> > >didn't include the 64mb card. Would you recommend that card? I ask
> because
> > >there is a pretty good deal on these at my local Costco.
> >
> > It depends... The Sandisk cards work, they will record in stereo, and 
>is
> are
> > very reliable cards. However the ones we tested did seem to have some
> minor
> > speed limitations with Repeater. With the cards tested, I was only 
>able to
> > record in stereo for about 3.5 minutes before repeater reports "CFC 
>Slow"
> > and it stops recording (mono went for the entire 8 minutes with no
> > problems). This only comes up when you have a 64 MB card or higher, OR 
>if
> > you are making extreeeeeeeeeeeemly long loops, OR if you are using
> Repeater
> > as a digital hard disk recorder because you went out and bought a 512 
>MB
> CFC
> > card. Considering most loops are only seconds long it's probably only a
> > minor limitation. The newer DaneElec and Simple tech cards seem to 
>have no
> > speed limitations with Repeater. Full stereo recording up to 8 minutes
> etc.
> > If you don't mind the minor speed limitations then you are probably 
>o.k.
> and
> > will be very happy with the Sandisk card you are eyeballing. See if you
> can
> > arrange to try before you buy or get a return grantee and then you 
>won't
> > have to worry.
> >
> > The following was written to the list earlier by Don, one of the 
>brainiacs
> > at Electrix who sweated blood to bring Repeater to life.
> >
> > Disclaimers:
> > 
>------------------------------------------------------------------------
> > 1. The following is based on my experience and is my personal
> >     opinion. It should not be taken to represent the official views
> >     or position of Electrix/IVL Technologies. (even though the
> >     conclusion is pretty much exactly the same).
> >
> > 2. The following only relates to CFC cards in the context of
> >     their use with Repeater, and implies nothing about their
> >     suitability or performance with ANY OTHER PRODUCT.
> >
> > 3. If you think I am being paranoid, I have been flamed badly
> >     in the past. All this having been said, flame proof underpants
> >     on and here goes...
> > -----------------------------------------------------------------------
> >
> > I noticed the discussion starting around CFC buys. There is some
> > stuff on the Electrix website, and also on a flyer shipped with the
> > unit. However you do need to be aware of card specs - the only
> > real way to know things are going to be cool is to test Repeater
> > with the card you wish to use. Until specifications become a
> > perfect art, rather than a marketting tool, that is just the way it
> > is.
> >
> > Electrix has been doing a lot of testing with different CFC cards,
> > and our recommendations are based on the results of those
> > tests.
> >
> > Technobabble follows
> > ---
> > CFC card specs that are published from different manufacturers
> > seem to cover the following:
> >
> > Burst-mode rate (quoted ~6-10MB/sec). Ignore this. Unfortunately
> > everyone who designs a CFC interface needs to design for the
> > lowest common denominator anyway, making this spec worse than
> > useless IMHO.
> >
> > Read rate. Typically 800KB/sec -> 2MB/sec. Read rate is not
> > really the issue. Reading flash memory is pretty damn quick and
> > in Repeater accounts for a fairly small proportion of the time
> > consumed at the CFC interface.
> >
> > Write rate. Quoted (ahem!) 500KB/sec -> 1.5MB/sec. However
> > this is the long-term sustained rate, and depending on the card
> > manufacturer, the data caching algorithms they use, and a whole
> > load of other variables the short-term variance in write operation
> > latency can be huge. I know - I have pored over the logic analyser
> > and scope traces looking into this phenomenon until I went bug
> > eyed [still in recovery...].
> >
> > CFC cards do some pretty nifty footwork under the hood to manage
> > the storage medium - including error recovery, bad sector
> > remapping, wear levelling etc... Also, writing is a cached
> > mechanism and there are additional time effects due to the caching
> > scheme used, the pattern of writes to the card and the amount of
> > cache available.
> >
> > The result of all of this is that an apparently fast card may
> > occasionally (or in the case of one card we tested, very often...)
> > take a long time to complete a write operation. Hit a few of these
> > long write operations in a row and all of a sudden Repeater will
> > have run out of write buffer space and will inform you that there is
> > an issue here...
> >
> > Most cards will handle the 'sequential' writing of mono operation
> > with no problems. Stereo operation is where most problems lie.
> > The pattern of writes to two .wav files can fight with the CFC
> > caching scheme and cause the card performance to be somewhat
> > less than desirable.
> >
> > So - that is the low down.
> > ---
> >
> > My advice is to read the specs (the faster card manufacturers will
> > quote them with pride. The slower card manufacturers will quote
> > them under a subtle disguise to make you think they are better
> > than they are...). Take all specs with a healthy dose of reserve.
> >
> > Then, if you can test a card before you buy, do. We are providing
> > information on cards we have thoroughly tested and are happy with
> > to help with purchase decisions.
> >
> > The Simple Technologies cards deliver. DaneElec also are just
> > dandy. This does not imply that other cards out there will not
> > also do just fine, but it provides a starting point. I hope that with
> > experience that this forum will provide more information about
> > good card choices for use with Repeater. We will also update
> > the information on the web site as more experience and test
> > results become available.
> >
> > Please consult the website and feel free to post questions
> > for us folks about CFC cards. We will be happy to occasionally
> > break the lurking mode and provide what information we can.
> >
> > Cheers, and I hope you folks have a *lot* of fun...
> >
> >         Don Goodeve
> >
> > (of Rik Elswit's 'Don and the Maniacs' fame... I kind of like that
> > one...)
> >
> > ps. CFC technology is moving *damn* quick these days, and the
> > speed of cards will become less of an issue as time goes on. With
> > Repeater we had to design towards where we expected CFC
> > technology to be, and fortunately our Crystal Ball did a pretty good
> > job.
> >
> > Respect,
> >
> > Damon Langlois
> > Creative Director
> > Electrix
> > Tel (250) 544-4091 Fax (250) 544-4100
> > http://www.electrixpro.com