Slow download speeds...is it the ISP or the CPU?

Briggz · Post by **Briggz** » Sat Feb 07, 2009 11:08 pm

Hi,

Thanks in advance for any guidance anyone here can provide.

I'm paying for a five Mbps down/1Mbps up cable service via Charter (Suffolk, VA). This is a new computer running Vista. I have an old cable modem (Motorola SB4200) connected via ethernet to my linksys wireless router. I have another computer elsewhere in the house connected wirelessly. Interestingly...the other computer seems to have reasonable download and upload speeds (around 3 Mbps earlier this evening at the same time primary computer was less than 1 Mbps).

I noticed about a week ago that the speed started to get horrible in the evenings (less than 1 Mbps down as measured via speakeasy.net).

I spoke with Charter service. No known issues in my area. He had me do a netstat check at the command prompt. It showed what he said was an excessive amount of TCP/UDP hits that were indicative of spyware.

Norton showed nothing but Spybot caught a virtumonde.sci trojan. I reran in safe mode and dumped the trojan. Still wicked slow...30 minutes to download Ad Aware.

IP Address: XX.XX.X.X (XX.XX.X.X)
Client OS: Windows Vista
Browser: Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0; WOW64; GTB5; SLCC1; .NET CLR 2.0.50727; .NET CLR 3.0.04506; Media Center PC 5.0)
Please Read the Analyzer FAQ if the above is not your IP address.

TCP options string = 020405b40103030201010402

MTU = 1500
MTU is fully optimized for broadband.

MSS = 1460
Maximum useful data in each packet = 1460, which equals MSS.

Default TCP Receive Window (RWIN) = 65700
RWIN Scaling (RFC1323) = 2 bits (scale factor: 2^2=4)
Unscaled TCP Receive Window = 16425

In Windows Vista, unless "TCP/IP Auto-Tuning" is disabled, only the Current TCP Window is displayed. Use the SG Vista TCP/IP patch instead of the TCP Optimizer for automatic tweaking.
RWIN is not fully optimized (even though it is a comparatively large number). The unscaled RWIN value is lower than it should be. Also, RWIN being close to and above 65535 does not justify the header overhead of enabling TCP 1323 Options. You might want to use one of the recommended RWIN values below.

RWIN is a multiple of MSS
Other RWIN values that might work well with your current MTU/MSS:
64240 (up to 2 Mbit lines, depending on latency. MSS * 44)
128480 (1-5 Mbit lines, depending on latency. MSS * 44 * 2)
256960 (2-14 Mbit lines, depending on latency. MSS * 44 * 2^2)
513920 (8-30 Mbit lines, depending on latency. MSS * 44 * 2^3)
1027840 (25-60 Mbit lines depending on latency. MSS * 44 * 2^4)

bandwidth * delay product (Note this is not a speed test):

Your TCP Window limits you to: 2628 kbps (329 KBytes/s) @ 200ms
Your TCP Window limits you to: 1051 kbps (131 KBytes/s) @ 500ms

MTU Discovery (RFC1191) = ON

Time to live left = 111 hops
TTL value is ok.

Timestamps (RFC1323) = OFF
Selective Acknowledgements (RFC2018) = ON

IP type of service field (RFC1349) = 00000000 (0)

mccoffee · Post by **mccoffee** » Sun Feb 08, 2009 5:07 am

Try running this in the vista box http://www.speedguide.net/files/vista/S ... _patch.cmd

Also try this post a log here ,or have them analyzer it to make sure the junk is gone out of the system.

Is the fimware up to date on the router? If not update it also couldn't hurt to leave the modem and router off for about 10 mins to allow everyting to resync

Briggz · Post by **Briggz** » Sun Feb 08, 2009 12:48 pm

Ran the optimizer...here is the new TCP Analysis:

« SpeedGuide.net TCP Analyzer Results »
Tested on: 02.08.2009 12:45
IP address: xx.xx.x.x
Client OS: Windows Vista

TCP options string: 020405b40103030201010402
MSS: 1460
MTU: 1500
TCP Window: 65700 (multiple of MSS)
RWIN Scaling: 2 bits (2^2=4)
Unscaled RWIN : 16425
Recommended RWINs: 64240, 128480, 256960, 513920, 1027840
BDP limit (200ms): 2628kbps (329KBytes/s)
BDP limit (500ms): 1051kbps (131KBytes/s)
MTU Discovery: ON
TTL: 111
Timestamps: OFF
SACKs: ON
IP ToS: 00000000 (0)

dlsayremn · Post by **dlsayremn** » Sun Feb 08, 2009 3:25 pm

Could you run a tracert to Yahoo.com. Also in command prompt run, netsh int tcp show global. Post results of both here.

Briggz · Post by **Briggz** » Sun Feb 08, 2009 4:35 pm

Yes...thanks for the help...

Tracing route to yahoo.com [206.190.60.37]
over a maximum of 30 hops:

1 1ms 1ms 1ms 192.168.1.1
2 * * * Request timed out.
3 9ms 6ms 17ms 172.22.33.241
4 9ms 9ms 9ms 172.22.33.237
5 15ms 20ms 17ms dca-edge-18.inet.qwest.net [72.165.200.233]
6 45ms 52ms 21ms dca-edge-18.inet.qwest.net [205.171.251.106]
7 * 24ms 16ms 63.146.27.98
8 17ms 18ms 17ms if-0-0-0-74.core3.AEQ-Ashburn.as6453.net [216.6..51.41]
9 22ms 22ms 22ms ix-14-2.core3.AEQ-Ashburn.as6453.net [63.243.149.110]
10 19ms 27ms 20ms ae2-p140.msr1.re1.yahoo.com [216.115.108.57]
11 18ms 18ms 17ms te-8-3.bas-a2.re4.yahoo.com [216.39.49.5]
12 17ms 19ms 23ms w2.rc.vip.re4.yahoo.com [206.190.60.37]

From the netsh int tcp show global:

TCP Global Parameters
Receive-Side Scaling State :enabled
Chimney Offload State :disabled
Receive Window Auto-Tuning Level :normal
Add-On Congestion Control Provider :none
ECN Capability :disabled
RFC 1323 Timestamps :disabled

mccoffee · Post by **mccoffee** » Mon Feb 09, 2009 12:41 am

download and save that patch and save it to the desktop after saying double click the vista patch and in the black screen hit y wait when it says done close out the command prompt..

It looks like those changes didn't get saved.

trogers · Post by **trogers** » Mon Feb 09, 2009 10:08 am

Briggz wrote:Yes...thanks for the help...

Tracing route to yahoo.com [206.190.60.37]
over a maximum of 30 hops:

1 1ms 1ms 1ms 192.168.1.1
2 * * * Request timed out.
3 9ms 6ms 17ms 172.22.33.241
4 9ms 9ms 9ms 172.22.33.237
5 15ms 20ms 17ms dca-edge-18.inet.qwest.net [72.165.200.233]
6 45ms 52ms 21ms dca-edge-18.inet.qwest.net [205.171.251.106]
7 * 24ms 16ms 63.146.27.98
8 17ms 18ms 17ms if-0-0-0-74.core3.AEQ-Ashburn.as6453.net [216.6..51.41]
9 22ms 22ms 22ms ix-14-2.core3.AEQ-Ashburn.as6453.net [63.243.149.110]
10 19ms 27ms 20ms ae2-p140.msr1.re1.yahoo.com [216.115.108.57]
11 18ms 18ms 17ms te-8-3.bas-a2.re4.yahoo.com [216.39.49.5]
12 17ms 19ms 23ms w2.rc.vip.re4.yahoo.com [206.190.60.37]

High and uneven ping times at hop 3. My guess they are a fallover from the ping times at the modem in hop 2.

Power off your modem and relocate it a few feet away from ALL other electrical devices to avoid electrical interference.

Also, ping times at the router are all 1ms. I gather you are using a wireless connection. Be careful of interference over the air from devices like cordless phone, bluetooth system and energy saving lamps.

Briggz · Post by **Briggz** » Mon Feb 09, 2009 10:40 pm

Reran the vista patch, upgraded my router firmware and relocated my modem...speed is through the roof now (approximating 8Mbps at 1030 est)...I think one of the Charter techs bumped me up to 10 Mbps service while troubleshooting.

Also, I got a call today from Charter saying they actually were having some equipment problems on their end and that they were supposed to have the offending equipment replaced tonight.

So, not sure if it was the tweaks or Charter getting their act together but it seems to be working fine now.

Thanks to everyone that helped. I'll update speeds tomorrow during the peak evening time to verify that I'm all done here.

Briggz · Post by **Briggz** » Tue Feb 10, 2009 7:16 am

At 0715 est, speeds are 7.7 Mbps down and 9.9. up. Pretty good. The true test will be this evening.