Date: Fri, 30 Jan 2004 13:08:17 +0100
From: Philip Nienhuis <[EMAIL PROTECTED]>
Subject: Re: [LIB] Networking problems
Raymond wrote:
>
> Date: Fri, 30 Jan 2004 09:32:18 +0800
> From: Raymond <[EMAIL PROTECTED]>
> Subject: Re: [LIB] Networking problems
>
> > > There is a logical explanation for all this and I'm almost certain the
> > > problem here is CPU power. There is a big difference between dumping
> > > digital videos through firewire at almost 30Mbps and only managing 5Mbps
> > > through a network card. Firstly, firewire cards (and, to a lesser extent,
> > > USB2.0 devices) have onboard controllers. In my card (and I assume almost
> > > all firewire cards), the firewire stream goes straight to system memory via
> > > the DMA (direct memory access, allows devices to read/write to/from main
> > > memory independant of the system processor) controller, bypassing the CPU
> > > altogether. All the CPU has to do is grab the data out of memory and shove
> > > it out to disk (the video is uncompressed and, as far as I'm aware, comes
> > > across the firewire cable in a format that is almost like uncompressed AVI
> > > anyway). In fact, if the video is already interleaved correctly, all the
> > > CPU needs to do is monitor the DMA controller until it says it has a block
> > > of data then tell the IDE controller (also on DMA) to grab data from that
> >
> >Are you sure about DMA in the Libretto?
> >AFAIK the Libretto 30-110 IDE (which is attached tru a plain vanilla ISA
> >bus)
> >simply has no DMA support. PIO mode 4 is the best I could ever get on my
> >Lib110 in Win2K, OS/2 and Linux.
>
> You might be right there ... although the Libretto's IDE controller IS on
> the PCI bus (well OK it's on the "Extended IO Bus" which hangs off the PCI
(Now you force me to look and search..... :-) )
No I think it is not on the PCI. Assuming it is authorative, in the
Lib100 Maintenance manual (pdf) I see on Figure 1.3 ("System Unit Block
Diagram") an unambiguously mentioned ISA bus (with an again unambiguous
"16 bit" indication) with attached *HDD* & YMF715 & Flash BIOS, hanging
from some "IO & PC-Card Ctlr GA" (probably Toshiba parlance/bloat for a
PCI-to-ISA bridge) which in turn hangs off the PCI bus.
Theoretically then it may still be different for Lib110, but I doubt it.
(BTW, I read elsewhere that even the PCMCIA/Cardbus hardware
implementation is not very optimal, as it uses polling for card
removal/insertion detection instead of interrupts. Not good for battery
life...)
> bus, which I don't think is the legacy ISA bus because it has the DMA
> controller and what I'm pretty sure is the DMA-enabled Cardbus slots
> hanging off it), I too can't get the hard drives to snap out of PIO mode
> (although it is in "DMA if available" mode) ... I might do some more poking
> around later though ...
What picture are you referring to? (in what document?)
Philip
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