10-01-2007, 06:02 PM
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| Junior Member | | Join Date: Sep 2009
Posts: 0
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 Re: TCP Stream in Win XP Pro?
Alex Lazarevich wrote:
> Within a GigE network infrastucture, I've got an XP SP2 Pro system,
> all updates installed, NIC is Intel Pro 1000 MT Server Adapter, with
> most recent driver from intel. I'm testing TCP-IP streaming from
> that client to my linux server which has two Pro 1000 MT server
> adapters in a bond. I run netperf-2.1pl1.exe from that XP client to
> a linux server running netserver, and I can't get more than
> 30-35MB/sec. Yet my linux clients, with similar hardware, get
> 90-100MB/sec netperf to the same exact linux server. It's not a load
> issue, as I've run the tests when the network is idle or busy, same
> results.
> Every single Windows XP client in our domain behaves the same way,
> just can't break the 35MB/sec TCP stream rate. Yet linux can break
> it easy no problem, so I doubt the problem is in the networking
> infrastructure. Problem ius in Windows XP.
> Any idea what's going on here? Does anyone else get TCP-IP stream
> rates greater than 35MB/sec on windows with the Intel Pro 1000 MT
> server adapter? Any OS tunning I need to do? I'd like to see at
> least 80-90MB/sec, similar to what linux can see.
What is the CPU utilization of each CPU in the system(s)? Which
specific linux kernels are you using? Are they supporting TSO?
(ethtool -k IIRC)
What sort of PCI bus is present in the systems? PCI-4X (64 bit, 66
MHz) or better still PCI-X?
What is the actual TCP window size on the wire? (packet trace of the
SYN's) IIRC there may be some small disconnect between the -S and -s
parameters of netperf and the actual window sizes used by Windows.
Generally speaking, to get good netperf numbers over Gigabit
neworking, one wants a window size of 64KB or better. There are of
course exceptions.
You might also want to test single-byte TCP_RR performance. Related
to the window size above, the single-byte TCP_RR test will be a decent
first approximation of the RTT between the two systems:
Tput <= Window/RTT
Might want to see if Windows is using large send.
rick jones
--
a wide gulf separates "what if" from "if only"
these opinions are mine, all mine; HP might not want them anyway... 
feel free to post, OR email to raj in cup.hp.com but NOT BOTH...
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