ls1i+@andrew.cmu.edu (Leonard John Schultz) (09/02/88)
I am considering purchasing either an IBM model 70 or an Apple Mac II. I
would appreciate anyone`s opinions or advise on the subject. I consider the
two just about equal in graphics, memory, storage, speed, and cost at the CMU
computer store. I believe the 70 has more potential for the future considering
the raw power and multitasking abilities of OS/2. I also may run CADD systems.
What do you think?
Len
Schultz
lsli@andrew.cmu.edugoosh@cisunx.UUCP (Walter Perz) (09/06/88)
In article <8X7VPiyS2k-0M0m1wg@andrew.cmu.edu> ls1i+@andrew.cmu.edu (Leonard John Schultz) writes: > > I am considering purchasing either an IBM model 70 or an Apple Mac II. I >would appreciate anyone`s opinions or advise on the subject. I consider the >two just about equal in graphics, whoa.... not if you get a good vga monitor and card... the Mac just looks like good graphics because of its small size... speed, when you consider speed, remember that the whole ibm family generally smokes the macintosh at i/o.... and that is what you notice the most. I believe the 70 has more potential for the future considering >the raw power and multitasking abilities of OS/2. yupper, also concurrent dos/386 is supposedly _really_nice >What do you think? > get a compaq 386 deskpro 20 megahertz for some serious @$$ kicking! Len Schultz >lsli@andrew.cmu.edu Walter Perz -- ============================================================================== Walter G. Perz goosh@cisunx.UUCP University of Pittsburgh goosh@pittvms.BITNET "Let me get my baseball bat to show you how much I appreciate you !"-Watterson
woan@cory.Berkeley.EDU (Ronald S. Woan) (09/08/88)
In article <12292@cisunx.UUCP> goosh@unix.cis.pittsburgh.edu (Walter Perz) writes: >In article <8X7VPiyS2k-0M0m1wg@andrew.cmu.edu> ls1i+@andrew.cmu.edu (Leonard John Schultz) writes: >> >> I am considering purchasing either an IBM model 70 or an Apple Mac II. I >>would appreciate anyone`s opinions or advise on the subject. I consider the >>two just about equal in graphics, > >whoa.... not if you get a good vga monitor and card... the Mac just looks >like good graphics because of its small size... > I think that Walter is thinking about the Mac's with the built in monitors because some of the monitors that can be attached to the Mac II are quite large. Then again, depending how much you are willing to spend, you can get nice monitors for the IBM-PC family (1280x1024 res. with 16 million colors). >when you consider speed, remember that the whole ibm family generally >smokes the macintosh at i/o.... and that is what you notice the most. This is a bunch of baloney, the SCSI drives that most Mac's are attached to will smoke our MFM drives. What really determines speed is how much you are willing to spend. > >get a compaq 386 deskpro 20 megahertz for some serious @$$ kicking! Get a model 70 with the 64k cache, 25 MHz '386, and 160 Meg ESDI and make the Compaq look as if it were standing still.
Elric-Kinslayer@cup.portal.com (09/09/88)
In a message a few back, woan@cory.berkley.edu wrote something to the effect that "The SCSI drives on the Mac II will blow away our MFM drives." This however, is NOT the case with the high end PS/2 machines which use ESDI controllers and drives, which is an enhanced and extended version of the SCSI standard. these drives most defiantely smoke ANY SCSI drive, and come with HUGE Capacities. I my self have installed multiple Wren V 300 mb ESDI drives in all sorts of computers for network purposes, and these things are HOT.It did take a while to figure out how to patch these drives into novell, I must admit,but, considering that this was about May and the drives were brand new, and we had no sources of information that had already installed them, this was to be expected. We were able to format them for normal DOS with out a hitch, I must say. And considering these drives are only the size of 1 full heght drive bay, I'd say we've just demolished the Mac II in Disk I/O. Elric-Kinslayer A.K.A Matt Mosshoder Usenet Address:sun!portal!cup.portal.com!Elric-Kinslayer
gary@apexepa.UUCP (Gary Wisniewski) (09/09/88)
In article <5489@pasteur.Berkeley.EDU> woan@cory.Berkeley.EDU.UUCP (Ronald S. Woan) writes: >In article <12292@cisunx.UUCP> goosh@unix.cis.pittsburgh.edu (Walter Perz) writes: > ... >>when you consider speed, remember that the whole ibm family generally >>smokes the macintosh at i/o.... and that is what you notice the most. > >This is a bunch of baloney, the SCSI drives that most Mac's are attached to >will smoke our MFM drives. What really determines speed is how much you >are willing to spend. > ... Walter is correct---the Mac (even Mac II) is slower at I-O. Although the SCSI interface and drives are faster, all Macs lack DMA capability. Thus, any PC with a fast MFM drive will beat the Mac. This problem extends to high-bandwidth network products as well. Ethernet boards have bandwidth limitations on the Mac since they can't do DMA. We're designing a database product for the Mac, and the I-O speed difference is a major design concern. -- Gary J. Wisniewski Apex Software Corporation {allegra,bellcore,cadre}!pitt!darth!apexepa!gary Phone: (412) 681-4343
seeger@beach.cis.ufl.edu (F.L. Charles Seeger III) (09/11/88)
Sorry, I couldn't let this one pass. Perhaps, someone that actually designs with this stuff can elaborate more. Or someone who understands what they were measuring could provide some benchmarks. In article <8887@cup.portal.com> Elric-Kinslayer@cup.portal.com writes: |ESDI controllers and drives, which is an enhanced and extended version of |the SCSI standard. No, ESDI is not an enhancement of SCSI. They are two different animals. Asynchronous SCSI is a 10 Mbps 8 bit bus. ESDI is also a 10 Mbps interface. A system with a SCSI disk (e.g. many SUN workstations) hae a SCSI interface on the CPU board or in its IO backplane connecting via a SCSI cable to another SCSI controller which then interfaces to the disk. THAT disk interface can be MFM, RLL or ESDI (or most anything else you want to build). Older SUN 70 MB SCSI disks used an MFM drive, while the newer 141 MB drives are ESDI. I don't know what disk interface Apple uses. There is probably some loss of performance in going from ESDI to SCSI to the IO bus rather than ESDI directly to the IO bus, but my guess is that it's mostly some added latency rather than though-put. The latter is typically more important. SCSI also gives you device independence on the interface and allow many devices to exist on one bus (e.g. tape drives, CD-ROMs, etc.). Then there is synchronous SCSI, which is much faster ... Chuck
jamesa@amadeus.LA.TEK.COM (James Akiyama) (09/13/88)
ESDI is not an enhanced and extended SCSI; it is, rather, an enhanced and extended ST506/412 bus. Note that both, ESDI and ST506/412, are low-level disk interfaces. Both specifications actually influence the method information is recorded onto the disk surfaces. SCSI is a high-level interface which is designed to be relatively device independent (although it is clearly designed for devices which access data in blocks rather than byte-by-byte). Initially, a properly designed ESDI interface had considerable performance benefits over its SCSI counterpart. This was due to the SCSI protocol overhead, and the fact that many SCSI drives were (and still are) basically ESDI encoded drives with a ESDI-to-SCSI translator. These factors (along with others) often caused about a 20% performance penalty. Currently, the margin is lower and less well defined. SCSI overhead has been reduced considerably and newer translators are much more tightly coupled to the physical disk drive. On-board track buffering and optimal seeking have made many SCSI drives equal to ESDI counterparts (sometimes outperforming them). While ESDI drives are limited to fixed transfer rate increments (and only up to 20 Mbits/secs), SCSI drives can transfer data at any speed (up to 40 MBits/sec asynchronously; faster synchronously). Also note that SCSI possesses much greater future capability since higher level protocols allow for much more "SMARTS" being placed in the disk drive (disk data caching, optimized request queuing, optimized seeking based on logical disk blocks, etc). Also, since SCSI is an 8-bit interface it should be possible to design a disk drive which simulataneously reads all eight data bits from parallel heads. Finally, SCSI is easily extended to 16-bit and 32-bit formats. All in all, I believe SCSI will take over ESDI in the long-haul. It is my belief that ESDI was offered more as an interim solution while the SCSI standard was (and still is) being ironed out. SCSI allows intrinsic drive optimization to be placed where it belongs, in the disk drive. James E. Akiyama jamesa@amadeus.LA.TEK.COM UUCP: ....!tektronix!amadeus!jamesa ARPA: jamesa%amadeus.LA.TEK.COM@RELAY.CS.NET DISCLAMER: These opinion are mine, not Tek's.
arwall@athena.mit.edu (Chumley Wood) (09/14/88)
In article <342@apexepa.UUCP>, gary@apexepa (Gary Wisniewski) writes: > >Walter is correct---the Mac (even Mac II) is slower at I-O. Although the >SCSI interface and drives are faster, all Macs lack DMA capability. Thus, >any PC with a fast MFM drive will beat the Mac. This problem extends to >high-bandwidth network products as well. Ethernet boards have bandwidth >limitations on the Mac since they can't do DMA. Well, that's almost true. The Mac does have the DMA chip; Apple just neglected to use it... -- ------------------------------------------------------------------------- | Anders Wallgren Back by popular demand: | | arwall@athena.mit.edu Bush-Noriega '88 - A Crack Team! |
seeger@beach.cis.ufl.edu (F. L. Charles Seeger III) (09/14/88)
In article <7057@bloom-beacon.MIT.EDU> arwall@athena.mit.edu (Chumley Wood) writes: |In article <342@apexepa.UUCP>, gary@apexepa (Gary Wisniewski) writes: |> |>Walter is correct---the Mac (even Mac II) is slower at I-O. Although the |>SCSI interface and drives are faster, all Macs lack DMA capability. ... | |Well, that's almost true. The Mac does have the DMA chip; Apple just |neglected to use it... I don't think this is the case. XTs use DMA for hard disks, but ATs don't. Nor do '386 AT clones. In these machines DMA is used primarily for floppies. It was faster to use DMA on a 4.77 MHz 8088 (8 bit bus), but faster to use the CPU on AT and better machines -- at least assuming well written code. Therefore, the CPU handles hard disk transfers on these machines. Apple may have found transfers were faster when done with the CPU rather than with the DMA chip. I don't know enough about the Mac to comment further. Chuck