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From: michaelv@iastate.edu (Michael L. VanLoon)
Newsgroups: comp.os.386bsd.questions
Subject: Re: Will this configuration work OK?
Date: 8 May 94 16:59:40 GMT
Organization: Iowa State University, Ames, Iowa
Lines: 83
Message-ID: <michaelv.768416380@ponderous.cc.iastate.edu>
References: <CpFv2u.Mvs@galaxia.network23.com> <2qi39g$cu0@agate.berkeley.edu>
NNTP-Posting-Host: ponderous.cc.iastate.edu
In <2qi39g$cu0@agate.berkeley.edu> alanp@cory.EECS.Berkeley.EDU (Alan Pearson) writes:
>In article <CpFv2u.Mvs@galaxia.network23.com>, David H. Brierley <dave@galaxia.network23.com> wrote:
>>2. Is the Adaptec card good? I read of some problem with an Adaptec card in
>>a system with 16 meg of memory. I have also seen a lot of people talking
>>about the Bus Logic cards. Are the Bus Logic cards better than the Adaptec
>>cards, and if so which card should I get?
>No idea here, perhaps someone else can comment.
There is no such thing as "the Adaptec card". Adaptec, like BusLogic,
makes a large line of cards. Which one were you referring to?
The Adaptec 1542 is a good card. However, it is an ISA-bus card which
means it won't work with more than 16 meg of RAM. Also, it will
dominate a slow ISA bus, making the machine slower than a VLB, EISA or
PCI bus card. Avoid ISA if possible on SCSI controllers.
The Adaptec 1742 is a good EISA-bus card, but Adaptec doesn't make it
anymore. The current line of Adaptec cards are the 27xx cards. DO
NOT BUY THESE! They are not supported, and Adaptec doesn't care that
we can't get low-level information for them to write new drivers.
BusLogic makes an entire line of cards that work just as well as the
Adaptec cards, and are generally cheaper. The ideal card would be the
bt747s, which is the EISA SCSI-II card (basically the same as the
Adaptec 1742). This is the card I run, and it's a really great card.
If you don't want to buy EISA, make sure you get a VLB motherboard,
and use the BusLogic bt445s. If you decide to go all the way to PCI
(which nobody else has tried yet with NetBSD/FreeBSD to my knowledge),
the bt946c would be your card. And, finally, if you have to settle
for ISA, the bt545s, or the Adaptec 1542 would be the card.
>>3. Is 16 meg of memory enough? I plan on using XFree86.
>More than enough (if such a thing is possible). Most people run XF86 with
>8MB ram (myself inlcuded). However, when doing a compile under emacs
>in XF86, it gets pretty slow, due to swapping. 16MB is good for serious
>work. I have heard of problems when running on a machine with >16MB, so
>be careful. Though FreeBSD-1.1 may have solved these.
16 meg would make a perfect machine.
>>4. Should I spend the extra money to get the EISA bus? Will the EISA bus
>>make a *noticeable* difference in system performance?
>Again, no idea.
If you can afford it, definitely. What kind of machine are you
buying? You really haven't given us much to work with in this post.
Is it a 486? Pentium?
Some people are touting the PCI bus. While the PCI bus may be really
great in about a year, right now it's kind of buggy and may give you
more grief than you bargained for. On the other hand, it's faster
than anything else on a PC.
EISA is definitely the best alternative at this point in time. It's
approximately 2-4 times faster than ISA bus, and similar in speed to
VLB (VESA Local-Bus). The difference is that VLB is basically just a
fast and wide ISA bus connection, which means its great for a single
device like a video card. But when you try to run something like a
SCSI controller in it too, it has horrible bus arbitration compared to
something like EISA, which is designed from the ground up to be a
multimaster bus-mastering bus. This means that on a loaded, busy
machine, the EISA bus is going to give you much smoother arbitration
between the various things on your bus, and will allow the CPU to do
more in other areas while the other bus masters do their work.
So, to make a long story short, get EISA if you can afford it. If
not, get VLB, but remember that it may not work nearly as well as
EISA. Either, however, will be quite a bit faster than straight
ISA-bus. You might consider PCI, but I would make sure the
manufacturer will take back your motherboard if it won't work with
NetBSD/FreeBSD, since there some rather buggy PCI chipsets out there.
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Michael L. VanLoon Iowa State University Computation Center
michaelv@iastate.edu Project Vincent Systems Staff
Free your mind and your machine -- NetBSD free Un*x for PC/Mac/Amiga/etc.
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