Re: SCSI Host Adapter (+ Re: 2 CPU servers)
Nicola Bernardelli <firstname.lastname@example.org> wrote:
> There was mention of a specific model, Buslogic BT-948: is it such a
> "low-end" card or one with that CPU onboard?
The BT-948 and all other "MultiMaster" models have onboard CPUs. The 948
is BusLogic's equivalent to the Adaptec 2940U. The 958 compares to the
The FlashPoint series of cards use the host CPU instead of a dedicated
CPU. You can get the cheapest one (can't remember the model) for around
$120 if you shop around. It also supports Ultra-20 transfers. I really
like these cards, but I have not tried one with Linux. I know they work,
but I don't know if you pay much of a performance penalty.
I suspect the performance penalty is small: the CPU on the other cards is
just a slow Intel 80186. With a fast machine, it's probably worth 0.5% more
CPU utilization. Has anyone benchmarked the difference with Bonnie on
identical systems and drives??
Note that the non-CPU FlashPoint models are the only ones available
with twin-bus configurations. BusLogic is marketing these at the server
segment. If the dedicated CPU was a big performance win, I don't think
they would do that.
> Better question: what do you think is a medium-high level BusLogic
> card with good price/performance ratio and - most important - well
> performing (reliable and fast) with Debian GNU/Linux?
I think if you can afford it, you should probably go with a MultiMaster
model. Otherwise get the cheaper FlashPoint model -- unless you need
two SCSI buses on one card. All of them will be reliable, while the
MultiMaster has a theoretical edge on speed.
> And what about 2 CPU usage? I read on this list recently that the
> kernel is getting mature for Linux with such motherboards:
Linux 2.2 will be a lot better, but 2.0 with the right patches seems to
work acceptably well. It's probably not a good fit for most people at
If you have any other questions about the BusLogic SCSI adapters,
I suggest reading "drivers/scsi/README.BusLogic" in the kernel
source tree. And check out the web page listed there, as well as
Make it idiot-proof, and someone will breed a better idiot.
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