I have multiple Lenovo T500 laptops that are getting horrible data transfer rates while on Win7 x64. These work fine when running WinXP. I have tried the latest drivers on both the Intel and Lenovo support sites. Also tried a couple previous versions with no luck. Has anyone seen this issue or have a work around to resolve?
maybe it's not a problem with your hardware but with Win7 x64 and the TCP Chimney offload: With chimney disabled the transfer rates workes very well again like in XP where chminey not existed:
To disable chimney type the following command as admin in the command line (but that's without any warrenty):
netsh int tcp set global chimney=disabled
See also KB951037 at support.microsoft.com