RE: [squid-users] Dual Bus machines

At 01:32 AM 08/13/2002, you wrote:
>How much traffic does your squid box work with?
>Standard PCI can manage up to 132 Mb/s, others faster.
>
>Hermann

Thats true, sort of, but not really. PCI can BURST to roughly 1Gb/s,
however actually sustained capability is about 400Mb/s with more than 1
active device on the bus. You can only burst 64bytes at a time, so there is
no way to actually achieve anywhere near 132Mb/s with transaction overhead,
so that number is really a fallacy. The more devices on the bus, the lower
the achievable throughput.

Given that a full duplex ethernet can eat up half of the real bus bandwidth
(if you have 2 it could dominate the bus), it would seem that running your
ethernets on a separate bus would allow the disk to use all of the standard
bus, and be a huge win for a disk cache. I read on this list that someone
claimed that a dual processor didnt make much difference, but most dual
processor MBs have 2 busses, and it seems impossible that it wouldnt make a
big difference if properly configured, except at low traffic levels.

Dennis
Emerging Technologies, Inc.
-------------------------------------------------------------------------------------

http://www.etinc.com
Bandwidth Management Appliances
Bandwidth Management software for LINUX and FreeBSD
Received on Tue Aug 13 2002 - 10:31:38 MDT