CompuServe Thread

#Intro

10 messages in this thread
#541From: Dennis HoffmanDec 21, 1994 2:32 PM
Hey – I just wanted to introduce myself and say thanks for the dedicated forum on DTV. My name is Dennis Hoffman, and I work for Avid Technology. I am the Storage Product Manager for the company. I am extremely interested in any and all comments about your experience, concerns and needs regarding storage solutions for Desktop Video systems (Avid or otherwise). And I will be happy to answer any questions I can regarding general video storage or Avid products. One warning: my knowledge of computer storage seriously outweighs my knowledge of the video production industry… but we're all here to learn, right. I welcome the interchange.
#590From: Steve Bennett/SYSOPDec 21, 1994 7:10 PM
Hi Dennis! Boy you are just what the doctor ordered. What are the fastest SCSI II Fast drives available now that you are aware of. RAIDs that act as a SCSI II Fast device are acceptable! Thanks in advance… -John
#608From: Michael W. ToweDec 21, 1994 8:52 PM
Hi John, >>>what are the fastest SCSI II Fast drives available now that you are aware of.<<< PMJI…. But as far as I know the Seagate Baracudas are about the fastest out there right now. But remember that is all subject to cange without prior notice….and it will the day after you buy it :-))) Regards, Michael W. Towe Falcon Video Productions Santee Ca.
#663From: Dennis HoffmanDec 22, 1994 9:37 AM
The fastest traditional hard drives (regular, fast SCSI-2 narrow) we know of are the IBM Ultrastar 4GB 3.5" drives. They easily sustain transfer rates of 4.5MB/sec off the inner sectors. They are slightly faster than the Micropolis and Seagate 4GB products, in that order. 4GB is now the smallest we deal with, so I don't have any numbers on the smaller drives. I'm positive they're slower, though. btw- Seagate has a "two-head" product in the 2GB capacity range which is even faster – but it's a lot more expensive, especially per GB. Arrays can be really confusing. Maximum performance can be limited by whatever SCSI bus you're on, and quite a few companies make products which can almost pin that. For example, take a wide SCSI bus and two of the aforemetioned narrow IBM drives and use any of a number of vendors' software to stripe the drives (technically not RAID but called RAID Level 0 by many) and you can bump performance up to the 8-9MB/sec range (on a wide bus). Now swap out those narrow drives and substitute two WIDE Ultrastar drives and you will see between 12 and 15MB/sec SUSTAINED. Burst data transfers from a pair of these drives or a pair of the 2-head Seagate's or the Seagate Elite-9 (9GB drive) seem to be clipped at around 17.3 MB/sec leading us to conclude initially that we are hitting the practical limit of Wide SCSI. There are additionally a number of hardware-based RAID solutions which have varying levels of performance and added features at the various levels, most notably data redundancy or parity. But none of these solutions will meaningfully outperform two or three software striped drives – at least in our application, unless you get really fancy (and expensive). Having said all this – please take note: if the rest of the system (SCSI bus host adapter, codec, internal cpu bus and memory management system) can't handle that data rate – screaming storage doesn't do you any good TODAY. Nonetheless, I have a recommendation that I always give Avid storage customers. Do not buy a single MB of storage today, unless you absolutely need it. Then and only then, buy the fastest, largest thing you can. That is the only way, until our industry matures, that you can maximize the useful life of the product before the inexorable technology curve trys to obsolete it. And as it becomes obsolete, it is not reasonable to expect the vendor to somehow take it back or upgrade it. So protect yourself as much as possible and then just accept the nature of this fascinating industry. I hope that helps.
#700From: Steve Bennett/SYSOPDec 22, 1994 1:41 PM
Dennis, Thanks for the informative and concise response. So Fast SCSI Narrow Drives today can sustaing 4.5MB/sec? Is there a "peak" that you are aware of? The reason that I ask is because the NewTek Video Toaster Flyer, which requires Fast SCSI Narrow Drives, says that at points, in the highest quality mode (>6.00 MHz @ -3db w/56dB s/n ratio), the Peak Data Rate can be up to 8.0MB/sec. They are recommending, specially modified, 2GB IBMs, 4GB and 9GB Seagates as Flyer compatible drives. -John
#826From: Dennis HoffmanDec 23, 1994 11:42 AM
John what I was giving you was sustained data rate off the inner partitions for single drives. The data rate on the outer partitions is significantly higher, and in the case of the 4GB IBM's, they definitely sustain about 8 on the outer sectors. Now remember, drives do burst data much faster than they sustain it. Depending on the kbyte size of the peak the Toaster demands, a given drive may be able to deliver the data straight out of buffer at very fast speeds. I don't know what the "special modofocation" is, sometimes just marketing hype, but it sounds like the safe answer is to stripe a pair of 4GB drives (IBM or Seagate or Micropolis). Striping will give the user very high sustained data rate across the drive and presumably should eliminate media management issues. Right now, you can get something like this from FWB, MicroNet and APS (and Avid customers can get it from Avid for less). But I can't promise compatibility with the Toaster. I really know very little about it.
#869From: Steve Bennett/SYSOPDec 23, 1994 6:23 PM
Aha, Thanks for clearing that up, I was thinking that the figures that you quoted were at the top-end, not the low-end… inner vs. outer cylinders. Is striping similar to formatting? -John
#1181From: Dennis HoffmanDec 28, 1994 11:46 AM
No, formatting is a low-level process used to physically map out the surface of the platters in the drive – for a 9GB drive it takes hours. Striping is an installation process where you download firmware to the drive telling it how to behave, who it's talking to, etc – for a pair of 4GB drives it take 10-15 minutes. It's similar to installing partitions. Some formatting utilities, in an effort to be user friendly and reduce bells and whistles, bundle the two processes into one "button", so when you install you also format – this is true for all floppy drives – but not many hard drives anymore.
#919From: Patrick JenningsDec 24, 1994 3:08 AM
Dennis, waitaminnit, striping a drive? Wassat? Something new every logon… Patrick.
#1180From: Dennis HoffmanDec 28, 1994 11:42 AM
Striping is the term used to describe the process of setting up two or more drives to work as a single drive. With software only or combo hw/sw products, you can "stripe" data accross two or more drives instead of loading it all onto just one drive. This allows the multiple drive group to read data (or play video) much faster than a songle drive could because they can work in parallel. This function is sometimes referred to as RAID Level O.