I just did a clean install of Windows 7 Enterprise RTM 64 bit on my system, replacing Vista Enterprise 64 bit... My broadband speeds are now pure dog puke... they were running between 25-30 Mbs and are now 3 MBs or less... I ran the tests at ndt.anl.gov and the results are shown below... in particular it says "Your PC/Workstation has a 62.0 KByte buffer which limits the throughput to 2.23 Mbps" I have comcast broadband... 16MBS Download and 2 MBS Upload... Oddly, the upload speeds are working properly I did install Nvidia's chipset drivers updating Windows 7's RTM supplied set, but it didn't improve or worsen the speed... My system specs are listed below too... Any ideas on this ? Thanks... mtgb **** SYSTEM SPECS **** CPU: QuadCore Intel Core 2 Extreme QX6700 MOTHERBOARD: EVGA NF680i - 122-CK-NF68-A1 O/S: Windows 7 Enterprise - 64 bit RAM: 8 GB (4x2GB Sticks) OCZ OCZ2RPR10664GK R @ 5-5-5-18-2T BIOS: P33 GPU: EVGA GeForce 8800 GTX (768 MB) Driver Version - 190.38 CLOCKS AND VOLTAGES: CPU - 3.0 @ 10x - 1.3325V FSB - 1200 @ 1.4V SPP - 1.50V MCP - 1.55V SPP <> MCP - 1.30V RAM Linked/Synced @ 900 Mhz @ 2.1 V **** ndt.anl.gov tcp analysis **** WEB100 Kernel Variables: Client: localhost/127.0.0.1 CurMSS: 1460 X_Rcvbuf: 262142 X_Sndbuf: 262142 AckPktsIn: 565 AckPktsOut: 0 BytesRetrans: 0 CongAvoid: 0 CongestionOverCount: 0 CongestionSignals: 0 CountRTT: 564 CurCwnd: 96360 CurRTO: 528 CurRwinRcvd: 64240 CurRwinSent: 5840 CurSsthresh: -616 DSACKDups: 0 DataBytesIn: 0 DataBytesOut: 2669520 DataPktsIn: 0 DataPktsOut: 1824 DupAcksIn: 0 ECNEnabled: 0 FastRetran: 0 MaxCwnd: 96360 MaxMSS: 1460 MaxRTO: 732 MaxRTT: 448 MaxRwinRcvd: 64240 MaxRwinSent: 5840 MaxSsthresh: 0 MinMSS: 1460 MinRTO: 292 MinRTT: 92 MinRwinRcvd: 64240 MinRwinSent: 5840 NagleEnabled: 1 OtherReductions: 0 PktsIn: 565 PktsOut: 1824 PktsRetrans: 0 RcvWinScale: -1 SACKEnabled: 3 SACKsRcvd: 0 SendStall: 0 SlowStart: 0 SampleRTT: 328 SmoothedRTT: 316 SndWinScale: -1 SndLimTimeRwin: 4360681 SndLimTimeCwnd: 816350 SndLimTimeSender: 5181590 SndLimTransRwin: 240 SndLimTransCwnd: 16 SndLimTransSender: 256 SndLimBytesRwin: 2178740 SndLimBytesCwnd: 174200 SndLimBytesSender: 316580 SubsequentTimeouts: 0 SumRTT: 123896 Timeouts: 0 TimestampsEnabled: 0 WinScaleRcvd: -1 WinScaleSent: -1 DupAcksOut: 0 StartTimeUsec: 911400 Duration: 10362451 c2sData: 3 c2sAck: 3 s2cData: 3 s2cAck: 3 half_duplex: 0 link: 100 congestion: 0 bad_cable: 0 mismatch: 0 spd: 2.06 bw: 50.71 loss: 0.000001000 avgrtt: 219.67 waitsec: 0.00 timesec: 10.00 order: 0.0000 rwintime: 0.4210 sendtime: 0.5002 cwndtime: 0.0788 rwin: 0.4901 swin: 2.0000 cwin: 0.7352 rttsec: 0.219674 Sndbuf: 262142 aspd: 0.00000 CWND-Limited: 224.19 minCWNDpeak: -1 maxCWNDpeak: -1 CWNDpeaks: -1 The theoretical network limit is 50.71 Mbps The NDT server has a 127.0 KByte buffer which limits the throughput to 9.10 Mbps Your PC/Workstation has a 62.0 KByte buffer which limits the throughput to 2.23 Mbps The network based flow control limits the throughput to 3.34 Mbps

Just in case anyone's watching this thread it turned out to be my ISP... good ole comcast... I did a hard reset on my cable modem and voila... 31.25 down and almost 7 up... SHEESH !!!! 8/19/2009 4:11 PM GMT 67.163.163.244 31.25 Mb/s 6.86 Mb/s 29 ms Washington, DC ~ 150 mi

I had a similar problem with my AT&T DSL. Don't know why.

Hi, Thank you for posting. To make the issue clear, could you please let us know the following: 1. The brand and model of this broadband modem. 2. How do you connect this computer to the broadband modem, directly or via a router? At this time, please try the following: 1. Boot the computer to Safe Mode with networking and see how it works. 2. If there is a router between the computer and the broadband modem, please upgrade the routers firmware. Meanwhile, I also suspect the issue may be related to the ISP or the broadband modem, please also contact Comcast regarding the issue. Thanks.Nicholas Li - MSFT