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Making
Multiple CDRW's Work On One PC
I
have a PC configured to burn to 2 CDR's at the same time at
speed of 48x or more. This
let’s me make 2 CDs in half the time.
Usually, I burn from my hard drive to the 2 CDRs.
The other day, I decided to burn from 1 CD to 2 CDRs.
I was rather surprised to find that the same setup that
worked when burning from my hard drive to 2 CDRs would not work
when the source files were on a CD. After some trial and error
I found that, like everything else, there are some tricks
involved for burning to 2 CDRs from CD.
Here
are the tricks:
1)
Do not put any CD drives on a RAID card. It looks like most
Raid cards only support PIO mode transfers for CD's [even
though hard drive transfers are UDMA]. This runs the CPU usage up so high that the burners
starve. All CD drives should be on non-Raid IDE based channels. This includes the source and the destination CD drives.
a) I do not know if USB2.0 or firewire connected drives would
have this issue.
b) Non-raid
'add-on' cards might be OK.
c) I suspect
anything controller that Windows labels 'Mass Storage Device'
will have this issue.
d) Its OK to put
your hard drive on a RAID card.
2)
It's OK to put 2 CD drives on the same IDE channel. In fact,
it's required since you can't use raid cards for CD drives.
You'll have to do this to get enough devices connected given
the 2 device / 2 IDE channel limit of your mother board [do not
use RAID cards or motherboard based RAID channels].
I could detect only very minor buffer re-fill
degradation [even at 48x burn speeds] using full IDE channels
with all devices talking at the same time. Remember, even at
48x, A CD’s transfer rate is only 7.2Kpbs. ATA 33 [most CDRW
drives are still ATA33] can handle 4 CDs @ 48x on each IDE
channel before the channel bandwidth was used up. Since you can
only put 2 devices per channel, you’ll never flood your IDE
channels doing this. So
don't sweat putting multiple CDs on the same channel.
Never put a hard drive on
the same channel as a CD drive.
Hard drives can flood the IDE channel.
Also, hard drives are usually higher than ATA33 – and
IDE channels always revert to the slowest device.
Putting a hard drive in the same channel as a CD drive
just slows the hard drive to ATA33 speeds.
3)
Make sure you have at least 256M of ram - more is better. Nero
consumed 210M of RAM on my system when burning to 2 CDs at the
same time. 1 CD at
a time took approx 115M. If
you want to do 3 at a time, you’ll need 384M.
4)
Make sure all devices being written to are the exact same make,
model and firmware. Different CD drives can use different spin
modes {i.e. PAV, CAV, PLV, CLV, etc}. Mixing spin modes causes
the buffers to starve as the drives try change transfer rates
during the burn process. Mixing
spin modes will generally limit you to 16x burn speed.
5)
Beware of Windows DMA auto-change. Windows loves to change the
DMA mode of non-related drives when you swap out drives. I got
nailed several times because Windows changed my UDMA CD source
drive to PIO when I added a CDRW drive - even though the source
drive had not been touched.
Check your DMA settings anytime you change/add/remove
any IDE device.
6)
Watch the CPU. Under normal copying, you should only see approx
1-10% CPU usage. Any higher and you should check your DMA
settings. CD copying is very non CPU intensive as long as DMA
is enabled for all involved devices. In theory you should be
able to make a Celeron 300 burn multiple CDs at a time.
If you see high CPU usage [above 20%], suspect DMA has
been disabled.
a) Do not believe
task manager’s CPU utilization.
80% CPU usage could be spikes of 100% with lows of 60%
averaged together. Task
Manager said I was running 80% usage due to the PIO mode of the
RAID card. When I
increased Task Manager’s refresh rate, it showed spikes of
100% with sags of 0%. The
0% was because the CD drive spun down during the 100% rush.
website additions:
We have made several additions to the web site
this month. We have added:
1) Obituaries Section, where we will
keep a memorial to all of our members that have passed on. This
section can be accessed from the bottom of the main website
page. Each obituary is the same one that was included in the
email notification sent to all members. 2)
There is a Java Calendar that will show you the months and
dates for any year you wish. It too is located at the bottom of
the main page. 3) At the top of the main page
there is another calendar that will show you the board and
meeting dates for calendar year 2003. 4) Lastly
we have added a number of additional counters to the website.
There are two at the bottom the main page, one on the sales and
special page and one on each newsletter. We are trying to find
out which pages are getting the traffic. For not we are using
multiple counters until we finalize on the one we want to keep.
We still have some issues to work out with our ISP.
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