Windows XP Service Pack 3

[Shibby007]

I have recently installed the new Windows service pack and didnt think that it would effect my download speed. I tryed downloading today and the speeds were realy slow. Is there anything i can do to fix this, previous to updating the service pack it was running at full speed. Any Help would be Much Appreciated

[jewelisheaven]

... Why do you assume it's the update? What have you already checked? All router and Windows settings are candidates... What is Ctrl-P -> Advanced -> net.max_halfopen value?

[Shibby007]

well im thinking it may be the service pack because before installing it there was no issues with the download speed, the value i have in there is 100

[Firon]

Set that value back to 8. Do not alter it.

[Shibby007]

alrite thanks mate, il give that a try

[magao]

What I expect happened is that you had earlier patched your tcpip.sys to allow more than the default 10 half-open connections (thus being able to handle 100 half-open connections), and upgrading to XPSP3 replaced tcpip.sys (putting it back to 10). This could have also happened with any Windows update. As a result, when tcpip.sys was replaced, your speeds tanked because you had huge numbers of connection attempts queueing up (and probably timing out) - so you were taking much longer to connect to a reasonable number of peers.

There is no need to patch tcpip.sys - 10 half-open connections is plenty for any P2P protocol. The only possible advantage is that you might reach higher speeds a little bit earlier - but considering I can ramp up to 300kB/s in a matter of minutes with the right swarm, and nothing will help with a bad swarm, that's a bit of a non-issue.

Personally, I have my max half-open connections set to 5 in uTorrent (reduced from the default 8) as I don't want other applications running on that machine (web browser, etc) to be negatively impacted by (at times) only having 2 half-open connections available.

[bent]

btw, does the lord devil patch work with SP3? according to the page, it works with Sp 2 only.

After all the updates, my speeds are crappy. Do i need to patch anything again?

[jewelisheaven]

Patching half open will not improve your download speeds. Investigate other factors first... including your installed software. Some / any firewall/AV/security software may create hooks which slow your transfers down. Check your hardware for running as fast as possible (UDMA x these days) and not PIO. Check your ISP to see if you are shaped during certain times of the day.

As always check the stickies and FAQ before saying it didn't work or there is no solution.

[GTHK]

To answer your question though, yes it does work in SP3. Though you should work on other things first like jewelisheaven mentioned.

[tonylung]

I had the same problem. Installed SP3 and utorrent stopped working (tracker offline or socket something...)

Just uninstall SP3 (ctrl panel, add/remove program), restart automatically and everything goes back to 'normal'. Changing half-open connection didn't work though.

Yes, the problem is in the tcpip.sys file.

[gomp]

I am using sp3.

lord devil patch works with sp3 tcpip.sys.

If leave on default 10 and leave on utorrent default 8 setting in my experience you will get problems and errors in event viewer logs. Based on that 10 clearly is insufficent.

Another possible cause of problems is in sp3 microsoft enabled blackhole detection to help automate mtu value, this in my opinion is too conservative and can slow down tcp speeds.

To disable do as follows.

open regedit

goto HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters

set EnablePMTUBHDetect dword value to 0, create it if it dont exist.

Reboot to apply.

[thelittlefire]

You assume incorrectly. With default values all builds of uTorrent prior to the 1.8.1 beta post 11xxx suffered from incorrect half-open detection due to network stack issues.

Thanks for the MTU reg key in any case.