MHS108@psuvm.psu.edu (Mark Solsman) (03/23/90)
I am buying a new 386-25. Which disk sub-system should it have? 1 - EDSI 2 - SCSI 3 - RLL ...why do you say so?
wallwey@boulder.Colorado.EDU (WALLWEY DEAN WILLIAM) (03/23/90)
In article <90081.181305MHS108@psuvm.psu.edu> MHS108@psuvm.psu.edu (Mark Solsman) writes: >I am buying a new 386-25. Which disk sub-system should it have? > > 1 - EDSI 2 - SCSI 3 - RLL > > > ...why do you say so? I say its not a simple choice!!!! You need to tell the net more about what you want to do and how much you want to spend-- Here are some of my over-simplified generaliztions: 1-EDSI Fast-efficient somewhat expensive--most top quality computers come with either this type of drive or the SCSI 2-SCSI Fast to Very Fast- expensive but getting better-seems to be wave of the future. Incompatable problems sometimes- Not totaly standardized- Make sure Hard Drive works with controler before buying. One companies SCSI is not necessarily anothers (but usually is). Still seems to be lack of software drivers for some things (OS/2?). Usually top quality---Look for "SCSI-2" in future. Not sure if you can use Utilities like Norton, etc. (COMMENTS???) 3-RLL is an upgrade from MFM, if you are getting a 386-25 and can afford it, go with the other two. If you do get an RLL controller, make very sure you get an RLL drive not an MFM.(Some MFM drives will work with RLL, but tend to fail like a month later). To find out more information check out one of the latest Computer Shopper Magazines They just did a special edition for Hard Drives, and makes for good reading. Now I've probably started a drive interface war.....I hope not, but please make comments, corrections, and additions. Dean Wallwey
jca@pnet01.cts.com (John C. Archambeau) (03/24/90)
Either ESDI or an IDE (embedded AT) drive.
// JCA
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*/jca@pnet01.cts.com (John C. Archambeau) (03/24/90)
wallwey@boulder.Colorado.EDU (WALLWEY DEAN WILLIAM) writes: >In article <90081.181305MHS108@psuvm.psu.edu> MHS108@psuvm.psu.edu (Mark Solsman) writes: >>I am buying a new 386-25. Which disk sub-system should it have? >> >> 1 - EDSI 2 - SCSI 3 - RLL >> >> >> ...why do you say so? > >I say its not a simple choice!!!! >You need to tell the net more about what you want to do and how much you >want to spend-- > >Here are some of my over-simplified generaliztions: > >1-EDSI > Fast-efficient somewhat expensive--most top quality computers > come with either this type of drive or the SCSI >2-SCSI > Fast to Very Fast- expensive but getting better-seems to be wave >of the future. Incompatable problems sometimes- Not totaly >standardized- Make sure Hard Drive works with controler before buying. >One companies SCSI is not necessarily anothers (but usually is). >Still seems to be lack of software drivers for some things (OS/2?). >Usually top quality---Look for "SCSI-2" in future. Not sure if you can >use Utilities like Norton, etc. (COMMENTS???) >3-RLL > is an upgrade from MFM, if you are getting a 386-25 and can >afford it, go with the other two. If you do get an RLL controller, make >very sure you get an RLL drive not an MFM.(Some MFM drives will work >with RLL, but tend to fail like a month later). > >To find out more information check out one of the latest Computer >Shopper Magazines They just did a special edition for Hard Drives, and >makes for good reading. > >Now I've probably started a drive interface war.....I hope not, but >please make comments, corrections, and additions. My peeve against SCSI is this, not one BIOS chip out there supports it and I have yet to see a decent SCSI host adaptor for it. I do grant that SCSI is fast, but I have yet to see a good host adaptor. I admit to not having seeing the WD7000 or the data specs on it, but I do know that there are some problems with using SCSI in some cases. You have to make sure the OS you're using supports the SCSI host adaptor in question. // JCA /* **--------------------------------------------------------------------------* ** Flames : /dev/null | My opinions are exactly that, ** ARPANET : crash!pnet01!jca@nosc.mil | mine. Bill Gates couldn't buy ** INTERNET: jca@pnet01.cts.com | it, but he could rent it. :) ** UUCP : {nosc ucsd hplabs!hd-sdd}!crash!pnet01!jca **--------------------------------------------------------------------------* */
MHS108@psuvm.psu.edu (Mark Solsman) (03/25/90)
Well, most people out there seem to think that scsi is the fastest and edsi
gets you more bang for the buck.
I saw an advertisment for Jameco: EDSI $169.95 @ 15m/bits / second
SCSI $349.96 @ 10m/bits / second
seems like esdi is better all the way around!
any comments?jca@pnet01.cts.com (John C. Archambeau) (03/26/90)
MHS108@psuvm.psu.edu (Mark Solsman) writes: >Well, most people out there seem to think that scsi is the fastest and edsi >gets you more bang for the buck. >I saw an advertisment for Jameco: EDSI $169.95 @ 15m/bits / second > SCSI $349.96 @ 10m/bits / second >seems like esdi is better all the way around! > >any comments? I think Jameco sells the WD ESDI controller for that price, oh well. I still would go with ESDI for the sake of my wallet and overall support. // JCA /* **--------------------------------------------------------------------------* ** Flames : /dev/null | My opinions are exactly that, ** ARPANET : crash!pnet01!jca@nosc.mil | mine. Bill Gates couldn't buy ** INTERNET: jca@pnet01.cts.com | it, but he could rent it. :) ** UUCP : {nosc ucsd hplabs!hd-sdd}!crash!pnet01!jca **--------------------------------------------------------------------------* */
neese@adaptex.UUCP (03/27/90)
>Well, most people out there seem to think that scsi is the fastest and edsi >gets you more bang for the buck. >I saw an advertisment for Jameco: EDSI $169.95 @ 15m/bits / second > SCSI $349.96 @ 10m/bits / second >seems like esdi is better all the way around! > >any comments? Firts SCSI is not a bus that is measured in bits/second. High end SCSI drives are running at 24Mhz today. The price of 349.00 is high. I have seen street prices for the AHA-154xA adapter at about 279.00. Still more than ESDI, but the 154xA is a very intelligent SCSI adapter that can't really be completely utilized under MS-DOS. My opinion: ESDI is great for MS-DOS, as long as all you want is hard drives. But if your system will have a QIC tape drive, CD-ROM, WORM, DAT or Exabyte, then I would go SCSI. You save the cost of another board/controller in the system. SCSI also offers an easier upgrade path. For instance, many of you have already run into the night,are of moving from a 10MBit ESDI drive to a 15MBit ESDI drive. You already know that you have to replace your controller to do that. And when you want to move to a 20MBit ESDI driver, you will have to do it again. This is not true with SCSI. SCSI doesn't care about the drive data rate. SCSI is more of a pain to move to due to the fact that there is not a standard in the industry for it. Adaptec, WD, Future Domain, and others all have a SCSI adapter boards, but none of them are compatible with the others. The other problem with SCSI is the performance you want is virtually up to the SCSI device you use. For instance, on my Quantum PRO80 drive I can get about 3.2MBYtes/sec data throughput, under DOS. With a Conner CP3100 drive I get about 500KB/sec. Big difference. ESDI does not suffer from this. Roy Neese Adaptec Central Field Applications Engineer UUCP @ {texbell,attctc}!cpe!adaptex!neese merch!adaptex!neese uunet!swbatl!texbell!merch!adaptex!neese
larry@macom1.UUCP (Larry Taborek) (03/27/90)
From article <90081.181305MHS108@psuvm.psu.edu>, by MHS108@psuvm.psu.edu (Mark Solsman): > I am buying a new 386-25. Which disk sub-system should it have? > > 1 - EDSI 2 - SCSI 3 - RLL > > > ...why do you say so? I bought and put together my 386 machine. I went with SCSI (2), because the transfer rate was just as good as ESDI, and SCSI will let me plug up to 7 devices into the SCSI bus. Those devices can be hard disks, floppy disks, worm or cdrom drives, quick tape systems, helical tape drives,... Right now I have a Mylex 386/25Mz Cache motherboard with 4MB of dram, and a Adaptec AHA1642 controller hooked up to 2 floppy disk drives and a Wren III 155MB SCSI drive. The throughput is just unbelievable! (ie fast). Hope this helps... Larry -- Larry Taborek ..!uunet!grebyn!macom1!larry Centel Federal Systems larry@macom1.UUCP 11400 Commerce Park Drive Reston, VA 22091-1506 My views do not reflect those of Centel 703-758-7000
phil@pepsi.amd.com (Phil Ngai) (03/28/90)
In article <25100007@adaptex> neese@adaptex.UUCP writes: |SCSI is more of a pain to move to due to the fact that there is not a standard |in the industry for it. Adaptec, WD, Future Domain, and others all |have a SCSI adapter boards, but none of them are compatible with the others. Is this ever going to get better? I refuse to consider SCSI as long as things are screwed up this way. -- Phil Ngai, phil@amd.com {uunet,decwrl,ucbvax}!amdcad!phil Boycott the census! With the history of abuse census data has, can you afford to trust the government?
neese@adaptex.UUCP (03/29/90)
>|SCSI is more of a pain to move to due to the fact that there is not a standard >|in the industry for it. Adaptec, WD, Future Domain, and others all >|have a SCSI adapter boards, but none of them are compatible with the others. > >Is this ever going to get better? I refuse to consider SCSI as long >as things are screwed up this way. Sorry Phil, I don't consider this to be screwed up. All these various vendors would have to sacrifice some performance to use the others interface. If Adaptec used the WD interface, we would have to give up scatter/gather and command queuing, if WD used our interface, they would have to implement said features. If both WD and Adaptec used the Future Domain interface we would give up a bunch of performance. Now don't get me wrong, I love standards, but I don't think a standard should be allowed to inhibit the potential performance of anyone's product. IBM has just announced thier SCSI adapters and we have yet another interface to be concerned with. They chose an interface they felt would be best suited to the application they designed for. I also feel that compatibility should not inhibit those of us who long for some really good disk performance for our high end 386/486/RISC/CISC machines. You might say that ESDI gives this performance level. And to some degree you are correct, but I have to be the one that has to deal with the nightmare of when a disk manufacturer introduces a 2xMhz ESDI drive and tell a customer that if you want that drive you will have to throw away your current controller and replace it with a new controller in order to run this wonderful high performance drive. To me this is absolutely ridiculous. I would rather deal with SCSI and all the permeations of the implementation that to tell a customer who has a zillion controllers in inventory he has to scrap them. This is all my own opinion. Roy Neese Adaptec Central Field Applications Engineer UUCP @ {texbell,attctc}!cpe!adaptex!neese merch!adaptex!neese uunet!swbatl!texbell!merch!adaptex!neese
neese@adaptex.UUCP (04/06/90)
> Well, most people out there seem to think that SCSI is the fastest and edsi > gets you more bang for the buck. > I saw an advertisment for Jameco: EDSI $169.95 @ 15m/bits / second > SCSI $349.96 @ 10m/bits / second > seems like ESDI is better all the way around! > > any comments? First of all, you can't really judge performance of a SCSI drive by the data rate off of the head. With ESDI it is a good indication as the data rate off the head is also the data rate to/from the controller in the CPU. With SCSI the bus is a bus that has defined timing requirements for handshaking that allow data to run around on it at up to 5MBytes/sec (50m/bits / second). The operating environment and the types of devices to be used should dictate which way to go. A single drive system will generally be better off with ESDI. But if it is a system that will also need a high capacity tape backup system, SCSI may be the better choice as you save the cost of the tape card. If you are running a multi-tasking or multi-user OS, then SCSI is a far better choice, if you use a decent adapter in the system. (The ST01/02 does not qualify). SCSI has the ability to access more than one device at a time thereby increasing throughput to a much higher level than ESDI is capable of. This also assumes you have selected some decent SCSI devices as well. As the data rate is not a fixed rate on the bus, you can have data throughput anywhere from 450KB/sec to 3MBytes/sec, at the BIOS level. Using the 154xA adapter, for instance, the bottleneck will always be the device on the bus, as the adapter can run steady data rates of 5MBytes/sec in its slowest configuration. Unfortunately, you can't rely on the device manufacturer's data rates they spec, as they are best case rates, with no bearing on reality. Experience has shown me that the only way to know what the real data rate is, is to hook it up and test the living daylights out of it. For the typical user, this cannot be done obviously. This is one reason I will make recommendations, when asked, concerning the best SCSI devices around today. There are also things the typical user can't know. Like, how well the device adheres to the SCSI standard. This is a real bag of worms. In selecting SCSI, software support should be a major consideration as well. Sounds like ESDI is a better choice from the nightmarish picture I painted doesn't it? Not really. It isn't that bad. I just think when making a choice it is best to be armed with the facts. And I make no attempt to color things. Roy Neese Adaptec Central Field Applications Engineer UUCP @ {texbell,attctc}!cpe!adaptex!neese merch!adaptex!neese uunet!swbatl!texbell!merch!adaptex!neese
jca@pnet01.cts.com (John C. Archambeau) (04/08/90)
derek@cimcor.mn.org (Derek Terveer) writes: >MHS108@psuvm.psu.edu (Mark Solsman) writes: >> Well, most people out there seem to think that SCSI is the fastest and edsi >> gets you more bang for the buck. >> I saw an advertisment for Jameco: EDSI $169.95 @ 15m/bits / second >> SCSI $349.96 @ 10m/bits / second >> seems like ESDI is better all the way around! >> >> any comments? > >I still think that SCSI is the way to go (at least for the near future). With >careful shopping one can pick up good deals on SCSI drives and thus overcome >the only real problem with SCSI, currently. I picked up a 150MB 16ms SCSI drive >for $650 fairly recently by looking in computer shopper. I have been really >pleased with it. > >SCSI may seem slower with a single drive, but it comes into its own when you >have more than one drive because it allows simultaneous action on all drives >hooked up to the controller; thus the more drives, the more efficient is your >overall disk performance. ESDI, as far as i know, is merely an "extended" >ST506 standard and will only allow one-at-a-time access to the (up to) 2 drives >found on a controller. > >derek >-- > .Signature under construction But you can't argue against the cost effectiveness and speed of ESDI. // JCA /* **--------------------------------------------------------------------------* ** Flames : /dev/null | My opinions are exactly that, ** ARPANET : crash!pnet01!jca@nosc.mil | mine. Bill Gates couldn't buy ** INTERNET: jca@pnet01.cts.com | it, but he could rent it. :) ** UUCP : {nosc ucsd hplabs!hd-sdd}!crash!pnet01!jca **--------------------------------------------------------------------------* */
feustel@well.sf.ca.us (David Alan Feustel) (04/11/90)
Could you give us a brief comparison of the 154x and 152x adapters made
by Adaptec? I'm familiar with the 154x but know very little about the
152x. Thanks.
--
Phone: (home) 219-482-9631
E-mail: feustel@well.sf.ca.us {ucbvax,apple,hplabs,pacbell}!well!feustel
USMAIL: Dave Feustel, 1930 Curdes Ave, Fort Wayne, IN 46805neese@adaptex.UUCP (04/11/90)
>Could you give us a brief comparison of the 154x and 152x adapters made >by Adaptec? I'm familiar with the 154x but know very little about the >152x. Thanks. The 152x adapter is a PIO (Programmed I/O) 16 bit SCSI Host Adapter. The 154x is a bus master 16 Bit host adapter. That is the basic architecture difference. The 152x card is being merketed primarily as a DOS adapter. It does have a BIOS for support of up to 2 hard disks and with the ASW-1210 ASPI driver can support up to 7 hard drives. Roy Neese Adaptec Central Field Applications Engineer UUCP @ {texbell,attctc}!cpe!adaptex!neese merch!adaptex!neese uunet!swbatl!texbell!merch!adaptex!neese
rspangle@jarthur.Claremont.EDU (Randy Spangler) (04/12/90)
In article <27800006@adaptex> neese@adaptex.UUCP writes: > The 152x adapter is a PIO (Programmed I/O) 16 bit SCSI Host Adapter. The >154x is a bus master 16 Bit host adapter. That is the basic architecture >difference. The 152x card is being merketed primarily as a DOS adapter. Now, my only question is "What's the difference, hardware-wise and functionality-wise, between the PIO and bus master?" Oh, and while I'm at it, does anyone know of any 32-bit drive cards? It seems this would be the way to go with the 386/486/etc computers which can handle 32-bit data paths. Would such a card actually give you a 2x speed increase, or is there another bottleneck? (Assume a 386 running at 25MHz) -- -------------------------------------------------------------------------- | Randy Spangler | The less things change, the | | rspangle@jarthur.claremont.edu | more they remain the same | --------------------------------------------------------------------------
phil@pepsi.amd.com (Phil Ngai) (04/13/90)
In article <6137@jarthur.Claremont.EDU> rspangle@jarthur.Claremont.EDU (Randy Spangler) writes: |Now, my only question is "What's the difference, hardware-wise and |functionality-wise, between the PIO and bus master?" One difference is that bus master doesn't work in systems that use memory mapping, such as 386s with QEMM-386 or 386Max. The memory management software doesn't tell the bus master what's going on... -- Phil Ngai, phil@amd.com {uunet,decwrl,ucbvax}!amdcad!phil The War on Drugs is the modern day Inquisition.