A Problem Solution (AMD Dual Core Specific Issue)

I've been having such a time with this problem, and I've finally solved it, so I wanted to let the moderators know about this one, hopefully get it stickied into a FAQ somewhere.

I was having issues with uTorrent crippling my network speeds. Not the speed of the whole network, just to the one computer using it. I had a Linksys WRT54G, so of course everyone assumed that was the problem, but check out the neat thing:

I have two computers using that router. One of them is Win 2003 with a HyperThreading processor, the other is Win XP with an AMD X2.

The win2003 one had upnp enabled, dht, 1000+ global connections and ridiculous upload settings, but never slowed my internet. not one bit.

The winxp one had reasonable settings, but would cause ping timeouts to even the switch it was connected to. weird, right?

Other symptoms were;

even when uploading at a meager 10kB/s, the other computer could access internet fine, but the computer uploading could not access anything at all.

Closing uTorrent would almost immediately solve the problem.

This, to me, rules out router and ISP issues, since both computers were networked in the same fashion. both had UPnP, DHT, the works. there had to be something else wrong.

After reading a lot of infuriating faqs, and a few long forum threads, indicating DHT, TCPIP.sys, or the Linksys WRT54G as the culprit, I noticed a weird thing with my ping commands: the longer uTorrent ran, the more ping replies I saw producing a negative ping reply: that's right, a negative value. (for instance, -145ms).

After googling this a bit, it stems from an error with AMD Dual Core processors and NVidia chipsets (though it might not be exclusive to these brands) -- it has to do with kernel level commands using incorrect processor affinities to run certain things, which would interfere with "realtime" based events, which could direly interfere with networking abilities, especially for heavy-hitting programs like uTorrent.

The fix for this issue is to install the AMD dual core processor driver for winxp/win2003. You might be able to operate "just fine" without it, so I know a lot of you might not have installed this, especially if it didn't come with your driver CD for your chipset (mine didn't)- after installing this driver and rebooting, all of my network issues with uTorrent dissolved immediately.

The drivers can be found here:

http://www.amd.com/us-en/Processors/TechnicalResources/0,,30_182_871_13118,00.html

If this has already been posted somewhere else, I apologize: I couldn't find anything in search results for "X2". Also didn't know quite where to post this... I hope someone finds this useful.

Cheers,

Nago.

Excellent detective work there, nago. Thanks for the heads up

I'm going to link to this in the first link in my signature. At least now I know for sure that asking for computer specs isn't so useless after all (I'd been wondering if there ever was a point ).

Thanks for the find and solution. Stickied.

New SP2 for Windows 2k3 servers will solve lot of problems I tested with standard and R2 edition and all so people who's have AMD 2X CPUs needs AMD Dual-Core Optimizer and AMD Athlon™ 64 X2 Dual Core Processor Driver for Windows XP and Windows Server 2003 Version (x86 and x64 exe) 1.3.2.16 from the web site up.

I dealt with this issue a few months ago, and not because of my slow torrent speeds; I have a WRT54G as well, thought that was the culprit. I started getting negative pings, and I was getting intermittent connectivity losses. I searched for hours on end, and finally came across this.

Basically what I'm saying is, I wish I had you two months ago instead of that no good Google.

That's interesting. Maybe this problem is just built into Vista, because I have a single-core AM2 processor, and I get that problem sometimes. Usually pausing the downloads, letting them hit 0 down, and starting them again solves the problem for an hour or so.

I'm hoping this could be the answer to my issues. I'm hardly getting over 0.5-5kbps in any direction, have tested tons of torrents with good seed/peer ratio, have made sure my ports are forwarded correctly etc. I have the same symptoms as the OP, network basically useless as long as uTorrent is running. Could it be my 3800X2? We will soon see as I'm about to install the driver. Fingers crossed...

If you're suffering from the same symptoms, then chances are very likely that the solution will help.

when i click add and remove a file on utorrent 1.7. utorrent freezess for a min. but when i use 1.6.1 and click add and remove a file it dos not freeze at all.

And how is that the same symptoms as the thread describes?

Oh yeah, that's right.

IT ISN'T.

Make your own thread.

Is there any reason that this hasn't been added to the FAQs?

Seems as though it should be there, since this thread could be hard to find, depending on search terms and logic used.

The same issue occurs with Windows Vista, but the solution dose not as the AMD 64 x2 driver update only works for WinXP. Any suggestions on a vista fix?

Try the dual-core optimizer, it is listed as supporting Vista Beta 2 and it's the one supposed to fix the timer issue most prominently present in some games. But I seriously doubt it helps you at all (I haven't even seen much any effect from it in XP, though I haven't had any issues with the CPU either).

Alternativly: In case Vista has something similar to XP's boot.ini, try adding /usepmtimer to the startup switches. It appeared for me in XP when I upgraded to dual-core CPU and it's supposed to fix something related to the dual-core processors. Don't blame me if this breaks something, though (likely only windows startup if anything. in case it does, it should be enough that you edit the boot.ini again and remove the switch).

Thank you so much, nago !!!

Looks like this is the solution for my upload problems.

Very good! =)

mister44

Still have the problem, driver didnt fix it.

I have the exact hardware and symptoms described by Nago in the initial post. Suggest anyone experiencing Linksys/Vista performance issues try the advice provided at...

http://blog.tiensivu.com/aaron/archives/814-Vista-and-some-Linksys-routersfirewalls-stalled-sessions-Workaround.html

It has eliminated my related performance issues to date.

Anyone know if this could affect Dual CPU AMD Machines as opposed to Dual Core?

I dont seem to have any such problems but I run a Dual Proc (Single Core on each) Opteron Workstation for my daily driver and I am just curious if its succeptable as well.

I had the same problem, never knew what I did to fix it though, dualcore optimizer.. heh.

Anyway, old SMC routers somehow identify this issue as a SYN Flood against your network, and will record (literally...) 100's-1000's attacks against you in just one hour of uTorrent.

SMC routers identify this issue in their logs as such:

2007/11/14 12:05:18 ** TCP SYN Flooding ** <IP/TCP> att.ack.ers.ip:someport ->> you.r.WAN.ip:someotherport

If your find your router log full with spam like above, your not as popular as you think, go update get the Dualcore optimizer.

Hey, I registered to this forum just to thank you for this post. I had this exact problem and I did what you said and it fixed it. It is greatly appreciated and thanks moderators for making this Sticky.

what about if i have an AMD Turion™ 64 X2 on a laptop?

is the driver still valid? can i use it?

Oh and by the way, thank you so much for this post - it seems it may have something to do with my slow downloads.

(plus that my internet provider doesnt allow me to open any ports except 8080, and utorrent port-test doesnt register it as open.)

Possibly.

While this may SEM off the subject...it isnt.... when overclocking my AMD 5000+ Black Edition (dual core) on M2N32SLI deluxe motherboard...I was having problems with attaining 3.2ghz which seemed to be easier for everyone else....they recommended the AMD dual core optimizer and the AMD dual core drivers....in my case on MY system they really messed things up....it turned out that it was the processor itself!

During the end of the life cycle for certain AMD procs they just aren't that.....good :/

In short I removed the AMD optimizer and driver and got another processor...problem solved.

What I'm saying here is...be careful....there is MUCH more involved with the AMD driver and Optimizer than is at first apparent...using them MAY make things worse. Even after talking with level 2 tech support at AMD they wouldn't "exactly" recommend the driver and optimizer......

I use UTorrent a lot and have no problems at all and I have one of the nasty routers too!

make sure you have a Ghost backup of your primary hardrive...because the AMD dual core drivers and optimizer dont ALWAYS make things better and once installed are almost impossible to remove w/o resorting to restoring from a backup IMAGE.

Im my particular overclocking trial and error I got another AMD 5000+ dual core and had NO problems. It turned out that the individual core temps of the 1st proc I had were almost 10-15C different temps...the new one had core temp diffs of less that 2-3C.....further I found out that the procs that DID over clock well (have fewer internal problems) were manufactured BEFORE the NAA9G series. The CAA9G the AAA9G were MUCH better processors.

Im not saying don't use the AMD dual core drivers and optimizers...I'm just saying have a good backup image BEFORE you try them

To get around the amd dual core issue you can try

VIRTUAL BOX

install windows or linux so you can install

utorrent and download via virtualbox

then your internet surfing should'nt be affected

i have the same problem when using utorrent the internet slows down to a crawl and times out

havent tryed the fix because i use virtual box

hope this helps

http://www.virtualbox.org/

Using VMs isn't a good workaround, considering the fact that they tend to have bad disk IO throughput, seek times, et al.

"Using VMs isn't a good workaround, considering the fact that they tend to have bad disk IO throughput, seek times, et al."

WHAT !!

anyway i am running 2 virtual box machines at the same time with both running UTorrent and my net isn't affected one bit

its working fine with virtual box ver. 1.6.2