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Re: scsi-ide



Hi,

Well, I don't agree with all what you said:

Take, for instance, the thing about BIOS. compare a good SCSI-adapter BIOS
with any standart
Award BIOS. The stupid limitation that C: MUST be the first master drive
drives me crazy about twice a week (luckily i have an old Premiere board
that can take the master disk on the second ide as c:). The SCSI-BIOS allows
you to choose from what ID to boot from, try this using IDE. Also,
connecting more than 2 devices (probably on a changing configuration) is
MUCH easier using SCSI (even if it's slower): you just set the ID and plug
it in ! Also never had a problem with differnt disks from different
manufacturers to cooperate on one SCSI bus (unlike some IDE drives). Even
though I use IDE at home, I build many computers based on SCSI without IDE
and they where nicer (IMO). Also SCSI takes up less IRQs/ DMAs than IDE
(again, once you connect things). As it goes I often take disks from
customers or prepare them or whatever. That's why I have to connect many
things to my computer.

But of course you are right saying that IDE is the better choice for
home/office systems.

Schlomo

-----Original Message-----
From: Peter Lorand Peres <plp@actcom.co.il>

>Let's get this clear:
>
>1. All modern EIDE disks use DMA transfer whenever possible. SCSI
>interfaces use the same, or, rare (high end) interfaces, use mapped
>caches, which are indeed faster, but cost the world.
>
>This means, that the overhead for a SCSI transfer and for an EIDE transfer
>of the same data will be in favor of EIDE on the same hardware class.
>
>There are EIDE adapter cards that cache and RAID up to 4 drives. Thay cost
>less than the equivalent SCSI solution.
>
>2. SCSI devices do not have different 'bus speeds'. Neither have EIDE
>devices, but Ultra-DMA devices only work with their own kind in enhanced
>mode on one same interface. Fast SCSI devices can, indeed, be operated
>together with slower ones.
>
>3. SCSI configuration and driver setup has been a major problem since
>forever on the PC architecture, while it works extremely well on others
>(example: Mac). EIDE has only given problems when generations chaged, and
>ppl. had to get used to new settings.
>
>4. The only REAL benefit of SCSI is in RAID/mirroring and CD-write
>operations and backups that can be done w/o the intervention of the
>computer, by using us-mastering controllers. The price of implementing
>this is so high, that many people simply buy one more computer to do all
>that and use a network to connect the things...
>
>5. While all EIDE devices are somewhat robust against 'pulling the power
>plug', SCSI devices are notorious for losing data under the same
>conditions. This means that a SCSI installation MUST run on an UPS. Add to
>this the increased power requirements of SCSI and you wind up with a scary
>price... The fact that 'pros' choose SCSI, does not mean that the average
>PC users (even power user's) installations must choose the same, excepting
>when he is: a) rich b) keeps up with trends at any cost c) reads too many
>advertising materials, and too little real-world performance comparisons.
>
>The latest trend in making EIDE CD-writers reflects precisely the fact,
>that the manufacturers have understood that they cannot sell that many
>SCSI devices to low end users, as they would have liked to.
>
>6. The so-called fire wire (IEEE 1394) will put an end to this within
>foreseeable time. It is likely that in consumer PCs, SCSI is going to 'go'
>first, because too many people use EIDE, and the ones who choose SCSI will
>upgrade fast to IEEE 1394 for the same reason they went for SCSI when they
>did. This will leave IEEE 1394 and EIDE to compete for a while. Although I
>believe that local-bus EIDE or something like that is coming rather soon.
>Technically, makeing the transition from EIDE to ultra-wide local bus (32
>or 64 bit) eide is nothing for the drive manuafcturers.
>
>On Wed, 3 Dec 1997, S. Schapiro wrote:
>
>> Hi,
>>
>> >> 4. SCSI is much better than IDE
>> >Huh ?
>> >SCSI better (not MUCH, but better) tham IDE in
>> >multiuser and server enviroment . Nothing more .
>>
>> I don't think so: SCSI is better the moment you want to connect more than
>> one decive (perhaps runningat different bus-speeds) and the moment you
find
>> out just how much CPU you IDE-disk is using up. Besides that you waste
less
>> of the rare interrupts when you connect more stuff (disks, cd-roms, a
tape
>> or a MO, a scanner etc.) to your computer.
>>
>> Schlomo
>>
>>
>
>Peter Lorand Peres
>------------------
>plp@actcom.co.il 100310.2360 on CIS (please use Internet address for mail)
>http://ourworld.compuserve.com/homepages/plp
>
>"The creed of Inland Revenue is simple: 'If we can bring one little smile
to one
>little face today - then somebody's screwed up somewhere' - David Frost
>
>(Note: The above stands valid in all countries until proven wrong)
>
>