OK I gots a question. My test server runs Server 2003 Standard 32bit. It has an Intel gigabit NIC, and connected to a NetGear gigabit switch. Yet in the Task Manager, Network tab, it only shows up as 100Mbps. Our other server which has the same OS, NIC(s) and Switch(es) shows up as 1000Mbps.

What am I missing?

Disable network auto detection and force the mode to 1000Mbps/full duplex in the driver's properties?

Network Auto Detection was not an option I could find. I did change the link speed to Auto-negotiated/1000 and that changed the Network performance tab to 1Gbps. I will have to see how it performs perhaps tomorrow.

We have an underlying issue that isn't actually with this computer. It is with our 2008 WDS Server where the network utilization is very low on incoming traffic and very high for outgoing. Since this 2003 WDS Server is way slower and using worse (unicast only) software support, there shouldn't EVER be a reason why it runs data over a test network faster than the 2008, but it does. Tomorrow I will now be able to do some side-by-side tests. Both servers are connected to their own private gigabit "LANs" aka a switch with one other PC on it.

Usually this is down to either driver support (aka good vs bad drivers), and/or TCP offloading. If you can disable offloading in the driver properties (usually something like TCP Offload or Large Send Offload) and reboot, you may see much better performance. Some drivers just aren't written properly, and when the OS goes to use the Scalable Network Pack features they say they support, bad performance, dropped packets, etc happens. Mostly Broadcom, but there could be others out there.

I will definately check that out then. The server that actually has the speed issue is running 2008 x64 and uses an Intel S5000PSL board. I am not going to think (of the bat) that it is a driver issue in this case, however our main theory is that there is an issue with the method we are transferring data.

I have confirmed that an upload cap exists on the Server 2008 machine. Its sad when our high-end 2008 server is slower than our low-end 2003 server.

The upload appears to be capped at 83KBps (0.83 of 1GBps). Test was transfering a 2.6GB WIM from my test computer to the network share on the server. Note that there does not appear to any download cap on the 2008, and it can xfer (out) close to its 1GBps limit. Here is a picture from the 2008.

edit: made mathematical error.

As a comparison, I did a similar transfer to a network share from my VPC machine to the 2003 server. It was the largest file I could find, a 1.7GB VHD file. It uploaded at 7% of 1GBps which is about 70MBps. So there appears to be a cap on the 2003 as well, but not as low as the 2008.

Server 2008
TCP Offloading enabled on both NICs.
Both NICs set to 1Gbps instead of Auto
Enabled TCP Offloading in Windows
No change to upload performance.
TCP Offloading also does not appear to be functioning during an upload.

sorry for troubleshooting both of these in the same thread.

Server 2003
I just came to the realisation, that in the previous 2003 test results, the client computer only had a 10/100 NIC in it. Seeing how I was getting 70% client/7% server, I can't complain about that. So I hooked up a PC with a gigabit NIC and did a file transfer. The results are as following:

File: 1.7GB WIM file
transfer with explorer: 23% = ~230Mbps
transfer with xcopy: 25% = ~250Mbps

So as far as the 2003 is concerned, we are seeing a 2% (on average) difference caused by the server being a Domain Controller. I read that there is an overhead difference when transfering files TO a domain controller. I would like to note that BOTH the 2003 and the 2008 are domain controllers.

I'm going to make a separate thread about the network/server layout, which I will edit to appear at the end of this post.

One last post before I leave for the weekend... I think I need to sleep on all this new stuff I learned today...

Server 2003
Disabled security options for Microsoft Network Server/Client: Digitally sign communications (always)

no change.

Ran PCATTCP to test network speeds. Default switches used ie: pcattcp -t -f M hostname

XP -> 2003 = 53.87MB/sec = 430.96Mbps
2003 -> XP = 73.39MB/sec = 587.12Mbps

These numbers are surely better, but then again they are with 1 packet, not with a large file. I will run this test on the 2008 on Monday. I am thinking that if we can get these speeds with file transfer to the Server from the XP computer, then that will be sufficient, as to how to get them is another story.

I also must note that while I am using a computer with XP to do this network testing, the computers that require this speed run in a WinPE on a RAMDISK (WinPE via PXE), so any configs done to the XP machine would need to be translated to the PE if they, in fact, do work to our benefit.

See you next week!

PS: check sig for server/network config in case you think its a problem with them.

I wanted to update on this thread. I had opened an SR with Microsoft regarding the Server 2008 and its upload speed. After much testing and debugging and uploading ginormous files, the issue has been resolved. The resolution was as follows:

Change the following registry keys to 0 from 1:
HKLM\System\CurrentControlSet\Services\Lanmanserver\parameters\EnableSecuritySignature
HKLM\System\CurrentControlSet\Services\Lanmanserver\parameters\RequireSecuritySignature

Overall network speed seemed to have been increased by this as well. Even transfers up and down to the file server are much faster.