#SCSI-II in A3000?
25 messages in this thread
Is it possible to use any of the new fast SCSI-II controllers in an A3k?
I would assume not, since the 3k's Buster was buggy, but no one seems to
mention this either way in any reviews.
I'm kind of thinking of getting one if I can, but requirements include the
ability to use a fast SCSI-II controller with a fast drive as well as a
good hi-res display card.
I'd really appreciate any info. TIA!
Paul
Paul:
I believe that the A3000's Buster can be replaced by the one that is the
replacement for the A4000 one. I think they came with C='s A4091. If you
replace the buster chip they should work fine in the A3000.
// -Mike Schiller
\X/ AMIGA! On AutoPilot in sunny Fort Lauderdale
Thanks Mike! I just hope supplies last, and I hope I don't have to stick
with the 4091 to get things working.
Otoh I heard that the Fastlane works w/ or w/o a good Buster. Do you
happen to know what if any problems there are running a busted Buster with
a Fastlane?
Paul
Fastlane goes slower and eats more CPU when used with busted buster.
—
Dale L. Larson, Intangible Assets Manufacturing
KRAP!!!!! DAMN!!!! How easy/hard is it to upgrade a 3k's Buster?
Paul
Pretty easy, but who cares? Do you have a Z-III DMA device you plan on
using in it?
—
Dale L. Larson, Intangible Assets Manufacturing
I think there might be more to it than just replacing Buster. Whether or
not there is, Fastlane's manual says that it works with some A3000s, but
doesn't specify how to figure out which ones.
There is no point getting a new controller for an A3000. The A3000s
built-in SCSI is very fast. You would be unlikely to notice any
difference at all. Your numbers might be a little better, but only if
you've got a *really* fast drive (majik or barracuda) or if you have
several fast drives (and I don't think there is a test program for
multiple drive access anyway).
—
Dale L. Larson, Intangible Assets Manufacturing
Well the thing is that if I get any new Amiga it will be to do sound
editing with an Ad516, so I'd be getting the fastest largest SCSI-II drive
I could afford, so I expect it probably would make a difference.
That thing about -some- 3000s is disturbing though. I'd rather spend a
few hundred for a 3k than thousands for a 4k at this point.
Paul
It won't make a $300+ difference. Trust me.
—
Dale L. Larson, Intangible Assets Manufacturing
Whu…? What won't make the difference? The choice between a 3k and a
4k? Or SCSI vs SCSI2 speed?
Paul
A3k SCSI is, for most intents and purposes, as fast as FastLane or 4091
SCSI. Yeah, the diskspeed numbers are a little better, but only for
access from cache. The sustained speeds of any available devices just
aren't that high. (Well, OK, there are RAID boxes, but I mean drive
systems under $2000.) If you're spooling audio to disk, you need speed X
and not a bit faster. I'm sure the A3k will easily get you speed X. What
is more important is an A/V drive which won't do a thermal recal in the
middle of your spooling.
There is no point at all in upgrading A3000 SCSI. Just like there is no
point adding external cache to an 040. You can't get enough speed out of
it to make it cost effective.
—
Dale L. Larson, Intangible Assets Manufacturing
Well I'll definitely try to use A3k built-in SCSI first, but don't SCSI-II
fast drives transfer faster by definition because their data bus is
running at 20MHz instead of 10, or something like that?
Paul
Trust me, trust me, trust me. I know a few things… 🙂
SCSI-I has a maximum theoretical transfer of 5MB/s. SCSI-II has the same
theoretical maximum. SCSI-II Fast (found on the 4091 and Fastlane) has a
theoretical maximum of 10MB/s. SCSI-II Fast Wide, 20MB/s.
Maximum theoretical and actual practical are not the same. The laws of
physics limit how fast manufacturers have been able to make drives spin,
and hence, how much data they can pull off the platters. RAM cache on the
drives can sometimes make the drive faster for certain kinds of
operations. RAID boxes (a simple example would be eight drives tied
together such that one is used for each bit of each byte read/written to
the array) can overcome this, but are not in your budget. The real
advantage of SCSI-II shows when multiple drives are being accessed
simultaneously, not when a single fast device is in use.
When testing a Barracuda drive with an A4091 and Fastlane, I was unable to
get over 5MB/s from the drive's cache. Zorro-III overhead makes it
impractical. The 4000T will do about 7MB/s from that drive's cache. But
again, these are not sustained speeds, these are cache speeds.
I'll say it one more time: There is nothing you are going to do with your
A3000 for which this is going to make a difference.
—
Dale L. Larson, Intangible Assets Manufacturing
Forgot to mention… No Amiga controllers are Fast Wide (20MB/s), only
Fast (10MB/s).
—
Dale L. Larson, Intangible Assets Manufacturing
Actually, I've only heard of one or two Fast Wide controllers anywhere. I
expect you'd need a massive RAID array of individually fast drives to get
anything out of it. I don't think even Adaptec makes a Fast Wide
controller.
Paul
There are several Fast Wide implemenations for various workstations.
RAID boxes filled with Barracudas do nicely one these.
There are even workstations with multiple Fast Wide controllers which can
move significantly more than 20MB/s through the filesystem sustained. I
think SGI makes such boxes.
These are not in your budget, nor mine.
—
Dale L. Larson, Intangible Assets Manufacturing
Dale-
I heard that there was a problem with the Barracuda and the Fastlane, but
the Fastlane people fixed it and made it faster. How much faster I don't
know, but faster nonetheless.
In any case, if I can get all 8 tracks of playback off 3k SCSI, I'll be in
pig heavan. It sounds as if it's an even better deal for me to get a 3k
if I can than I thought. If I got a 4k I'd -have- to get a seperate
controller, and I doubt I'd be able to afford a 4k. Although that depends
on it's monitor-less price. But even then, availability is practically
zero, so a 4kT is a moot option for me.
Paul
I thought the max xfer from SCS-1 was 2mb/sec? (That is the right answer
on the A+ exam required of certified computer technicians anyway.) Thanks
for the explanation of RAID boxes, that clarified it to me. Do they work?
I see nothing in that to address the access or headsettle delays, which
are the biggest throughput killers one would think.
alternate: jonest@hfsi.com
I never met a man I didn't like…Will Rogers
2? No.. I never heard that. Maybe it is though for 8bit controllers?
I'm just guessing on that though. I really have no idea. 5 is what I've
always heard.
Paul
Well, you've pretty much summed up my opinion of ceritification for
technicians, etc. 🙂
—
Dale L. Larson, Intangible Assets Manufacturing
Question….
Can the AD516 do crossfades between two different audio files? (IE: could
it do a "radio station" seque… as one fades in, the other fades out?)
Chris – Fast and Low on my '020!
"If you don't straighten up young man, you'll grow up to be President!"
Yup! I'm not sure of exactly what all it's capabilities are, but it can
do dissolves and cuts and level-controls and so on with as many tracks as
you can play at a time.
Paul
Cool… I see a potential new market for the Amiga, assuming someone buys
it and continues to produce product!
Chris – Fast and Low on my '020!
"If you don't straighten up young man, you'll grow up to be President!"
I just talked to someone at Advanced Systems & Software International
Group, which is the company handling the Fastlane in the U.S. I think, and
they said that the problem with the Fastlane and 3000s is unknown and
seems to randomly afflict them without respect to motherboard rev, buster
rev, or anything else they know about now. He said they tested 12 3000s
and 6 worked. Go figure. So I'm probably making a very big gamble if I
buy a 3000.
Paul