[Gllug] OT Firewire/Fast Networking

[Simon A. Boggis]

On Wed, 2002-12-11 at 01:17, Mike Brodbelt wrote:
> On Mon, 2002-12-09 at 23:14, Matthew Thompson wrote:
> > > No. Firewire gives 50KB/s, while modern IDE drives can handle 100MB/s 
> > > or
> > > more (in bursts, at least -- sustained numbers are likely to be a bit 
> > > lower).
> > 
> > Firewire is rated at 400Mbps however it is the Oxford 911 chipset that 
> > is used in most Firewire drives which will be the bottleneck here - 
> > this limits to around 40Mbps.
> 
> I've not met the Oxford chipset so can't comment on it's performance or
> lack thereof. However, I've got an Adaptec firewire card, and I can
> happily get it bursting to nearly 200Mbps with my Iomega peerless drive.
> The bottleneck is the transfer rate of the disk - I'd be surprised if I
> couldn't get the full rated speed out of the interface.

I've got two firewire external enclosures with 2.5 inch (laptop) drives,
one enclosure has an oxford chipset and the other doesn't. I got bored
enough to swap the same disk between the two a while ago and did see a
marked improvement - I can't lay my hands on the non-oxford figures atm,
but from memory I think I was getting ca. 12000 K/sec for block reads.

With the oxford chipset I get:

Version 1.02b       ------Sequential Output------ --Sequential Input- --Random-
                    -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP
xxxxxxx          1G  4177  92 16553  34  8665  15  4698  97 19828  16  70.2   1
                    ------Sequential Create------ --------Random Create--------
                    -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
              files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
                 16   187  99 +++++ +++ 19581 100   188  98 +++++ +++   900  94
xxxxxxx,1G,4177,92,16553,34,8665,15,4698,97,19828,16,70.2,1,16,187,99,+++++,+++,19581,100,188,98,+++++,+++,900,94

That works out to about 155Mbps unless my brain is all fuzzy. I'd be
suprised if this isn't disk (Fujitsu MHN2200AT) limited - my newest
travelstar performs about the same on an IDE interface.

I haven't done IP over firewire for a while, but last time I tried it 
many moons back (between two sony vaios) I got very impressive
performance using netcat (:

Simon


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