RE: [squid-users] Dual Bus machines

At 02:53 AM 08/14/2002, you wrote:
> > Thats true, sort of, but not really. PCI can BURST to roughly 1Gb/s,
>
>Standard PCI with 32 Bits and 33 MHz? I dont think so.

Uh, yeah it is. 132MB/s is 1.056 Gbps. Dont get your bps and Bps mixed
up. Just multiply by 8 :-)

> > Given that a full duplex ethernet can eat up half of the real bus
> > bandwidth (if you have 2 it could dominate the bus),
>
>What sort of cache would use 400 Mb/s Network bandwidth constantly?

A true transparent cache on a busy (ISP) network. It doesnt have to be
doing it "constantly" Any active bus transfer on the same bus will
"hold-off" the disk transactions, and disk-transactions will "hold-off" the
ethernet transfers, so everything will slow. You cant be transferring an
ethernet frame at the same time you are reading and writing from disk if
they are on the same bus. Every time and ethernet card is receiving and
transmitting a frame at the same time its using 200Mb/s, which is quite
often. If you have 2Mb/s, then it wont matter. If you have 80Mb/s, then it
will matter.

> > I read on this list that someone
> > claimed that a dual processor didnt make much difference,
>
> > but most dual
> > processor MBs have 2 busses
>
>I havnt heard this, and i use more than one Dual PCs.
>Esp. not two PCI busses, of course they have two processor busses.

Most P3 dual MBs use the ServerWorks chipset, which has separate 32bit and
64bit busses. Most 64 bit MBs have more than 1 bus. If you have slots that
run at different speeds, then they are separate busses.

I suppose that if you have your cisco router proxying off to a cache
machine on the side the bus is not a factor, but if you are doing it all in
one system it certainly will be. but even on a system like that, dual
busses or a faster bus will reduce latency.

DB
Received on Wed Aug 14 2002 - 10:26:17 MDT