[mythtv-users] Noobish network cable connection question, basement > upstairs

[Dan Wilga]

At 2:11 PM -0500 12/5/08, Graham Mitchell wrote:
>On my desktop, the onboard gigabit (and the add on card I am planning), are
>on the PCIe bus (internally, and a 1x). At the server end, the disks are all
>on PCIe (and I know I can get about 140 G/sec out of them locally). SO I am
>hoping that I can get some more speed out of my setup. Of course, my switch
>will only let me have 4 teams in total, and I'm using a couple of them for
>this... but it will still be nice.

One thing I found out recently is that not all onboard gigabit 
ethernet hardware is created equal. Having jumbo frames support is 
important, IMHO.

I bought a new(ish) motherboard with an nVidia Corporation MCP51 
ethernet controller. This uses the forcedeth linux driver. The 
problem is, this motherboard chipset only supports normal (MTU=1500) 
frames. The result is that I only get about 330 Mbps from this port.

So I got a Marvell-based PCIe card, which supports 9000-byte MTU. The 
result is 990 Mbps throughput between the frontend and the backend. I 
can now record two HD programs on the backend using an HDHR on the 
same network, while also recording two SD programs on the frontend 
(saving via NFS to the backend), and watching an HD program (via NFS) 
on the frontend.
-- 
Dan Wilga                                                        "Ook."