#Do I need an A/V drive?
26 messages in this thread
ALL
I will be burning to a 2X CD-R. No audio or movie files, just large data files.
I current have a fast 1Gig EEDI drive. Do I still need an A/V drive?
Thanks,
DON
Don,
<<Do I still need an A/V drive?>>
It depends on your recorder. If you've got enough RAM in the recorder your
"fast 1Gig EEDI drive" should work fine.
(or copy it to tape and have us make the CD-R for you).
Jerry Warner
CD Solutions, Inc.
Jerry,
I plan to get a 1 meg buffered CD-R. Is that sufficient?
DON
Don,
<<1 meg buffered CD-R>>
Personally I wouldn't risk it with a buffer that small. I'd want 2 MB for that
type of drive I think but admit my experience with those drives is limited.
Jerry Warner
CD Solutions, Inc.
Our tests with the Sony 920S have proved very successful. The 1 mb buffer is
fine.
Mark,
Thanks, what pre-mastering SW do you use?
DON
Jerry
I posted this question in a few hard drive forums:
FYI I got a technical reply from the Seagate forum which states that AV
friendly drives should be used whenever large files are transferred. Basically
they said I need one.
DON
PS I didn't want to repost someone else's words withoout permission. Check
thread betweem myself and Ron of Seagete technical support.
Don,
I use all AV drives myself but I've talked with people who are using regular
drives without problems as long as they bump up the RAM. Talk with Georges
Brown from CD Archives as he has some experience in this area. Georges Brown
73243,2356
Jerry Warner
CD Solutions, Inc.
Jerry,
I will get either a 2 meg buffer or the SCSI AV drive. I suspect the buffer
option will be somwhat cheaper in the short run.
Thanks,
DON
Don,
Please do the following calculations:
a Recorder will write 150 KByte per second in single speed
300 KByte per second in double speed and 600 KByte per second at 4x speed.
With these numbers you can easily calculate how long the recorder can continue
to write without input data for more than 6 seconds on a device with 2 MByte
buffer recording at double speed. Within 6 seconds even the slowest harddisks
will have finished their recalibration.
Another example: 4x recorder with 512 KByte buffer. In this case the buffer
amount lasts for less than a second making a A/V drive nessecary or
<advertisement on> a CD Recording software which handles the data transfer to
the recorder asynchronously and is capable of feeding data into the recorder
even if the harddrive is currently not able to deliver data.
Sincerely Peter
Peter,
Thanks for explaning how this works, I am new to this field (as I suspect are
many people writing about it).
I suppose the safest thing for people to say is "get a SCSI AV drive".
I would like to quote portions recent articles, which are a source of
confusion:
Dr. Ash Pahwa, CD-ROM Professional May 1995, page 104:
" To avoid buffer underrun, a fast hard disk should be installed in the system,
but this hard disk should not have a "thermal recalibration" feature. (A hard
disk with thermal recalibration feature will stop intermittently to dissipate
heat from the drive, which can result in a data transfer pause.) Hard disks
that do not have thermal recalibration usally have a suffix of AV, which stands
for audio video; for example Micropolis makes 2217 and 2217 AV hard didk
drives.
Jim Seymour PC Magazine mar 14, 1995 page 100:
"Look for a 1GB or 2GB SCSI-2 drive, and make sure the one you chose does not
use thermal recalibration, a process that stops from time to time to adjust
head movements to compensate for changes in temperature.
According to a Seagate tech person, these articles should have said delayed or
intelligent Tcal, not NO TCAL.
Now you are adding that TCAL is only needed under certain conditions. I was
looking at your calculations
Let me see if I got this right:
My system will likely be as follows:
300 KByte per second double speed transfer
1 meg CD-R buffer
6 second thermal recal (a guess)
Assuming the the buffer is full, it would empty in 3 seconds, and I would get a
coffee coaster.
I would be OK if : I had a 2 meg bufferI
I had a 3 second TCAL hard disk.
Two more questions which occur to me:
What happens if the TCAL happens at the very start of writing ?(the buffer
cushion is empty)
How does your software compensate for this?
DON
Don,
if the buffer of the CD-R is still empty during the TCAL nothing will happen as
the CD-R will wait until it's buffer is full before starting to write.
Sincerely Peter
Don,
I might also add that when you're recording several small files instead of
larger ones it takes a larger buffer or you'll have the same problems.
No one ever said this was easy. It's still new technology and there's a
learning curve that goes along with something this new. It's also an ever
changing field. A year ago we talked about a "non-thermal recalibration hard
drive" or AV drive. We did so because it didn't recalibrate while we were
trying to read/write. Someone got the idea to call it "Intelligent
recalibration". It's mostly a sales technique if you ask me because the two
are really the same. To some degree you can tell how long a player has been in
this game by the terms they use. If they just came in, they don't know the
older terms. If they tell you that you can make a disc with a very small RAM
buffer, they haven't made many discs. If they alwasy say one premastering
package is best, they haven't made many types of discs.
Jerry Warner
CD Solutions, Inc.
<< A year ago we talked about a "non-thermal recalibration hard drive" or AV
drive. We did so because it didn't recalibrate while we were trying to
read/write. Someone got the idea to call it "Intelligent recalibration". It's
mostly a sales technique if you ask me because the two are really the same. To
some degree you can tell how long a player has been in this game by the terms
they use. If they just came in, they don't know the older terms. >>
Jerry
After a few weeks of checking this out and getting many contradictory sounding
responses, I finally discover it is a question of semantics. This is the last
thing one looks for in a technical discussion!
Well thanks to you and others in this forum, I finally got some pointed
answers.
I finally KNOW that I need an "AV-friendly" (new buzzword?) SCSI (with its own
controller), fast drive. I WILL get a 1 meg buffer CDR, I WILL will do an
image file (as speed is not important to me)….
…and I will pray to the gods of Dr. Ash Pawah (eastern CDReligion)
regards,
DON
After checking out the hard forums,
If they tell you that you can make a disc with a very small RAM buffer, they
haven't made many discs. If they alwasy say one premastering package is best,
they haven't made many types of discs.
Jerry Warner
CD Solutions, Inc.
<…and I will pray to the gods of Dr. Ash Pawah (eastern CDReligion)>
You should address your prayers to Ganesh, who is the god of (among other
things) writers! <G>
Best,
Deirdre'
Incat Systems
Jerry
The third question. Can I determine how long my current drive takes for TCAL?
It is a new WD caviar 3100 1 G drive.
DON
Don,
Sorry, no answer to that question. Can anyne please jump in?
Peter
I think one thing that has done this industry no good is people in PC and
Windows magazine ect writing on what should be done to make good CDs. These
are writers not people in the "know" Talk to the One off Shops or CD Solutions
or us (CD Archive) who actually use the stuff.
The last article I read raved about the CDR 1000 and CD Creator. Not the setup
most people would pick!
My personal opinion is a drive with a big buffer 2MB or more. In WFW with
32bit Disk/File access you will see faster performance from some of the EIDE
drives than a SCSI AV drive. If you were using Win 95 or NT you might see
better performance from a SCSI drive.. We use NT.
Cheers,
Georges
CD Archive, Inc.
http://www.cdarchive.com
Geoges,
On a related topic, It has come to my attention that Maxtor has an IDE drive
called the 7850AV. This is the first I hear of a non-SCSI AV drive. This would
be good as I would save an expansion slot and the cost of the SCSI controller.
Although I have my doubts about Maxtor technical support, what would you think
is the downside of this as in a standard WIN config EIDE is generally faster
than SCSI?
Any comments?
DON
I have heard of this drive and we have ordered a few to see if we can use them
in our "plug in the wall and play" systems. They seem to be backordered by a
few days and we won't have them for at least a week.
I'll let you know then what we think. I am NOT an expert but I don't see why
they couldn't make an AV IDE drive.
Georges
>>I think one thing that has done this industry no good is people in PC and
Windows magazine ect writing on what should be done to make good CDs. These
are writers not people in the "know"
Hear, hear!!! You're going to love my September column.
Aw, c'mon, Dana — everybody knows you're a writer, therefore you don't know
anything <G,D&R>
Kathy
<<<Hear, hear!!! You're going to love my September column.>>>
I will look for it in the mail.
O.k. while I'm at it what is <G,D&R>? What is my deal on the net I can figure
all of them out? I'm bad a crossword puzzles as well 🙂
Georges
G,D&R=Grin, duck, and run. There's a comprehensive list of online acronyms and
emoticons (like ;->) in the library of the Writer's forum.
I will go look for the file… so I can get up to speed 😉
Georges
Peter,
<< with 2 MByte buffer recording at double speed. Within 6 seconds even the
slowest harddisks will have finished their recalibration.>>
Thank you for confirming my advice to go with the 2MB buffer.
Jerry Warner
CD Solutions, Inc.