kevin@horizon.UUCP (Kevin Criqui) (09/23/88)
My appologies if this has been asked (and answered) before. I just recently got net access. Due to a bizzare upgrade path, I currently have an XT style hard disk controller in my 286. I'm ready to buy a 16 bit AT controller and have one last question. Is it worth the extra money to get a controller that can use a 1:1 interleave? My machine is a 10 MHz, 0 wait state 80286 so speed shouldn't be a problem (should it?). I have also heard that you need a 28mS step drive for 1:1 to work. Is this true? I guess I've been wanting to upgrade my ST238 anyway... Another question comes to mind. Has anyone tried to format a Seagate ST4096 RLL (2,7)? I have heard that it won't work, but they said my ST225 wouldn't either and it works great. Email if you can. I can't help you with the path (yet) as I am still trying to figure it out myself. Thanks. _kevin
davidsen@steinmetz.ge.com (William E. Davidsen Jr) (09/27/88)
In article <241@horizon.UUCP> kevin@horizon.UUCP (Kevin Criqui) writes: | ... I'm ready to buy a 16 bit AT controller | and have one last question. Is it worth the extra money to get a controller | that can use a 1:1 interleave? My machine is a 10 MHz, 0 wait state 80286 If you're running DOS it is. If you're running UNIX, probably not. The reason is that most 1:1 controllers work with a combination of hardware and firmware in the controller ROM. Therefore, UNIX, which doesn't use the firmware, does not benefit. | Another question comes to mind. Has anyone tried to format a Seagate ST4096 | RLL (2,7)? I have heard that it won't work, but they said my ST225 wouldn't | either and it works great. There is an RLL version which is a lot more money and appears to be nothing but a hand selected 4096. Most 4096's will run RLL okay (I'm running some) but it's not guaranteed. If you're trying to save a few bucks I'd try it. At 4096 prices you can probably sell one 4096 at a loss, buy another, and still be hundreds ahead of the price for the RLL version. Disclamer: I said it's not guaranteed. -- bill davidsen (wedu@ge-crd.arpa) {uunet | philabs}!steinmetz!crdos1!davidsen "Stupidity, like virtue, is its own reward" -me
berger@clio.las.uiuc.edu (09/28/88)
If you take the route of selling an ST-4096 that has been formatted under RLL, successfully or not, please be sure to tell the purchaser. Seagate absolutely will not service the drive, in or out of warranty. I've run a couple of ST4038 and ST4096 drives under RLL with no problems.
gerard@tscs.UUCP (Stephen M. Gerard) (09/28/88)
In article <241@horizon.UUCP> kevin@horizon.UUCP (Kevin Criqui) writes: >. . . >hard disk controller in my 286. I'm ready to buy a 16 bit AT controller >and have one last question. Is it worth the extra money to get a controller >that can use a 1:1 interleave? For the most part, it is better to use 1 to 1 interleave. This, however is somewhat dependant on you applications program. Programs that do not use reasonable sized disk buffers can actually run slower with lower interleave factors. This is due to the fact that the program goes through a cycle of: 1.) Read data 2.) Process Data 3.) Goto 1 If the task of processing the data takes longer than the gap between the record just read and next disk record to be read, the controller is forced to wait for that data record to come back around to the read/write head. Commands that use decent sized buffers will perform much better with lower interleave factors. >My machine is a 10 MHz, 0 wait state 80286 so speed shouldn't be a problem >(should it?). A 10MHz 0ws AT clone will work nicely with 1:1 interleave. >I have also heard that you need a 28mS step drive for 1:1 to work. Is this >true? I guess I've been wanting to upgrade my ST238 anyway... The step rate and interleave factor deal with different aspects of a disk's performance. The step rate is the time required to reposition the disk drive's read/write head to a different cylinder. The interleave factor determines the amount of time the controller must wait before it can read the next logical record from the disk drive. Hense, we can see that the step rate determines the amount of time required to position the disk's read/write heads to a different cylinder, and the interleave factor determines the best possible rate in which the data on a given cylinder can be transfered. So to answer the question, No, you do not need a 28ms step rate to take advantage of a 1:1 interleave factor. However, upgrading from a ST238 is never a bad idea if possible. >Another question comes to mind. Has anyone tried to format a Seagate ST4096 >RLL (2,7)? I have heard that it won't work, but they said my ST225 wouldn't >either and it works great. Seagate's media quality and testing methods are questionable. When using RLL technology you are in effect increasing the density in which the data is stored on the drive. I have seen many Seagate drives format just fine with RLL controllers only to become unbootable in a few hours. I have also seen many Seagate's using MFM controllers that need to be reformatted much more often than higher quality drives. (Warning: Strong opinion coming) The only drive that Seagate makes that I would recommend is the ST4096. I would not however, use any Seagate drive with an RLL controller unless it was one of their drives that is specifically rated for RLL. They have a model ST4144R which I believe to be an RLL rated 4096. At least the pricing should be similar, it has the same geometry as the 4096. Sorry for the Seagate bashing. I have seen too many problems with Seagate drives to feel comfortable with recommending them in general. At least you do not have a Miniscribe :-). Hope that this helps, Steve ------------------------------------------------------------------------------ Stephen Gerard - Total Support Computer Systems - Tampa - (813) 876-5990 UUCP: gerard@tscs ...tscs!gerard US-MAIL: Post Office Box 15395 - Tampa, Florida 33684-5395
sid@linus.UUCP (Sid Stuart) (10/01/88)
In article <17700021@clio> berger@clio.las.uiuc.edu writes: > >If you take the route of selling an ST-4096 that has been formatted >under RLL, successfully or not, please be sure to tell the purchaser. >Seagate absolutely will not service the drive, in or out of warranty. > >I've run a couple of ST4038 and ST4096 drives under RLL with no >problems. Yes, but if you reformat it with an MFM controller, how are they going to tell it has been formatted with an rll? sid@linus ps. I am not being sarcastic, I really want to know.
sl@van-bc.UUCP (pri=-10 Stuart Lynne) (10/03/88)
In article <40430@linus.UUCP> sid@milo.UUCP (Sid Stuart) writes: >>If you take the route of selling an ST-4096 that has been formatted >>under RLL, successfully or not, please be sure to tell the purchaser. >>Seagate absolutely will not service the drive, in or out of warranty. >Yes, but if you reformat it with an MFM controller, how are they going >to tell it has been formatted with an rll? Well most people only want warranty work when it's busted. And good luck getting it re-formatted when it doesn't work. -- Stuart.Lynne@wimsey.bc.ca {ubc-cs,uunet}!van-bc!sl Vancouver,BC,604-937-7532
cem@ihlpf.ATT.COM (Malloy) (10/03/88)
In article <40430@linus.UUCP>, sid@linus.UUCP (Sid Stuart) writes: > In article <17700021@clio> berger@clio.las.uiuc.edu writes: > > > >If you take the route of selling an ST-4096 that has been formatted > >under RLL, successfully or not, please be sure to tell the purchaser. > >Seagate absolutely will not service the drive, in or out of warranty. > > Yes, but if you reformat it with an MFM controller, how are they going > to tell it has been formatted with an rll? > > I am not being sarcastic, I really want to know. I also wanted to know so I called Seagate and asked. They said that the first thing that the "techs" do is a low level format of any drive that is sent back for repair. So, if you format an MFM drive as RLL, they will not know it since they will low level format it to MFM before they do anything else. If you do a low level format of a previously formated drive, the previous format will NEVER be known. Clancy Malloy ...!ihlpf!cem