Re: Replication on the backend

On Tue, 2005-12-06 at 23:19 -0500, Jan Wieck wrote:
> It's not so much the bandwidth but more the roundtrips that limit your 
> maximum transaction throughput. 

I completely agree that the latency is counting, not the bandwith.

Does anybody have latency / roundtrip measurements for current hardware?
I'm interested in:1Gb Ethernet,10 Gb Ethernet,InfiniBand,probably even p2p usb2 or firewire links?

At least Quadrics claims(1) to have measured only 1.38 microseconds.
Assuming real world condition would give you 5 microseconds, on a 3 GHz
processor that's 15'000 CPY cycles. Which is IMHO not that much any
more. Or am I wrong (mental arithmetic never was my favourite subject)?

RegardsMarkus

[1]
http://www.quadrics.com/quadrics/QuadricsHome.nsf/NewsByDate/98FFE60F799AC95180256FEA002A6D9D