I'm having a very strange problem. We just recently attempted a conversion to the "cloud" for all of our office workstations and servers. We very quickly realized when we went live that we were having issues with bandwidth. I ran probably hundreds of speedtests on all of the machines and they were all getting speeds of 16/3.8 on average we pay for 50/5 so I called my ISP immediately and they took a while but finally escalated the issue enough to get it resolved....sort of. I now have 2 machines in my office that are able to connect at the 50/5 speeds but the 8 other computers are still getting the same 16/3.8. I am able to connect a laptop to a patch cable at my desk and get the full 50/5 so I know that it's not any of the equipment/hardware enroute to my desk. (we also tested at the modem, switch, firewall and were able to get the full 50/5) The 8 computers that are having problems are
Win XP sp3
EVGA Nvidia nForce 680i SLI MB.
CPU is Intel Core 2 Duo E6600 2.4Ghz 1066FSB 4096MB L2 Cach Dual Core VT EM64T.
Graphics card is: nVidia Quadro FX 1500 256MB DDR3 PCIe 2x DVI Dual Link.
2GB RAM
(The two newer computers that are not having issues are Win Vista) I think my network card is the problem but I've downloaded the latest drivers and even updated the BIOS and still no change. I've tweaked the setting in the Nvidia Control Panel but nothing has changed. I'm tweaking them blindly because I'm not sure which if any setting is the problem. This is driving me crazy and keeping us from being able to complete our conversion. All of the computers are on the same network, switch, firewall etc.  I would appreciate any input you may have as to what could possibly be the problem. Thanks in advance for your help.

are they all on the same switch or are they on different switches or come from different network closets? if they are on different switches then i would look there for either a switch, cable or backbone issue. I do know that win Vista and win 7 machines do run a little bit faster for me also but nothing as drastic as that. 
 
also you if you are using long DHCP lease times or static IP's you may need to refresh the nic  via the ipconfig
http://www.microsoft.com/resources/documentation/windows/xp/all/proddocs/en-us/ipconfig.mspx?mfr=true

yes, we are a small office. 1 server, 1 router, 1 switch, 1 firewall etc. all of the computers are in the same network with the same equipment.
I will try release/renew to refresh my IP.....thanks for the suggestions.....fingers crossed

well, i know Vista has TCP auto tuning and XP doesnt, but i think they patched it in in sp3, so that may be why Vista is performing better than XP. you may need a TCP tweak to get the XP pc's to comply correctly. sometimes a patch like that doesnt always work correctly and a manual tweak is needed.  

wmmills


well, i know Vista has TCP auto tuning and XP doesnt, but i think they patched it in in sp3, so that may be why Vista is performing better than XP. you may need a TCP tweak to get the XP pc's to comply correctly. sometimes a patch like that doesnt always work correctly and a manual tweak is needed.  

+1 a incorrect mtu setting will cause problem also. 

hay, thanx quad! i guess this must have gotten resolved?!?! :) well, while im patting myself on the back, heres one for you too quad.  :P

Ok, I have refreshed my IP (several times)
I have manually reset my MTU in the registry to 1500
I have replaced my cable to Cat6
If I reset my network card to use anything but autonegotiate it won't work at all (this is typical of all of my problem pcs that are this same configuration)
none of the changes that I've made make any difference on my speed test to my cloud server. I plug in my laptop from home and voila i get my expected 50/5 internet speeds consistantly.
Any other ideas?
 
Update:
I purchased a new DLink Gigabit PCI adapter model # DGE-530T
and sadly, no change. I reset the jumbo packets to 7K which is the max setting
I changed from auto-negotiate to 1Gb Full Duplex - no change
 
Is there a setting in XP that could be causing this?

 i would say XP SP3 is def your problem. what i would try, just to see if thats the case, is to get another old small drive... like 40gb or more, and put vista on one of the problem machines that had xp sp3 and see if it has the same connection issue. that will at least tell you whether its XP or not and you can work from there. wish i could be more help man!