Date: Mon, 07 Jun 2004 00:59:44 -0400 From: Chuck Swiger <cswiger@mac.com> To: LukeD@pobox.com Cc: freebsd-questions@freebsd.org Subject: Re: Please help me understand pciutils output Message-ID: <40C3F640.2050101@mac.com> In-Reply-To: <Pine.NEB.4.60.0406061152350.14275@otaku.freeshell.org> References: <Pine.NEB.4.60.0406061152350.14275@otaku.freeshell.org>
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Luke wrote:
> I suspect that my PCI bus is incompatible with some of the PCI cards I'm
> trying to use with it. The motherboard was made in 1996 and these cards
> are all much newer. One of the cards gives USB 2.0 support, but I'm not
> getting anywhere near USB 2.0 speed out of the USB 2.0 devices I plug
> into it.
More details about the USB performance in terms of numbers you are seeing from
some benchmark would be very useful.
[ For instance, I know that I can get about 90% utilization of Firewire by
seeing a 45MB/s transfer rate for an external Maxtor 5000 combo drive, and I
get 1.5MB/s transfers for USB 1, but I haven't had a chance to benchmark the
unit using USB 2. And then mention something such as, I was running "dd
bs=8192", or benchmarks/iozone, or some such...]
> I wonder if the problem is the speed of the PCI bus that the
> USB controller is plugged into.
Well, a 33MHz PCI bus is still twice as fast as USB 2, but your MB is old
enough that pushing two devices might be enough to saturate the chipset-- so
you might see a difference between dd'ing between the USB device to /dev/null,
and from the USB device to, say, a hard drive.
> I installed pciutils-2.1.11_1 and ran "lspci -vv" to get the following log.
>
> Should I be disturbed by the "66Mhz-" status on everything except the
> RAID card, which is "66MHz+"?
No.
> Should I adjust the latency on anything?
Woah! Let's consider some easier things than going into wizard mode. :-)
> Should I stop plugging new cards into old boards?
>
> 00:00.0 Host bridge: Intel Corp. 430HX - 82439HX TXC [Triton II] (rev 02)
Maybe. Your motherboard is one of the earlier 66MHz FSB boards, and my memory
suggests that the FX and maybe the VX had serious issues involving broken
support for doing L2 caching if you had more than 64MB of RAM, and stuff like
that. I think the HX fixed some but not all of of those issues, and the LX
was the final revision which was quite good for the time. Dell used the LX
motherboards ("Aladdin"?) for most of their PII systems, until replaced by the
100MHz FSB and motherboards with the relatively famous BX chipset.
There's nothing wrong with P2-grade hardware, however, other than being dated,
and I'm happier using comparitively cheap P3-grade processors today rather
than P4-based spaceheaters, or AMD even, and using the cost savings on better
equipment elsewhere in the system.
--
-Chuck
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