Twin PCs but speed is different...

[olhorobot]

hi! i'm a SNB reader for some time and having a problem with my network i thought that you might help me.

thank you in advance.

i have 2 twim pcs (they have exactly the same hardware) with ethernet onboard, the motherboard is a supermicro X7DWA.

i have a small file server on another pc.

i connect them with a SMC smcgs16 switch

when i'm openning P.ex. a photoshop file with +1GBytes from the file server with PC-A i can see in the Task Manager/network tab only 7% of the bandwidth is used. From PC-B a average of 60% is used.

I've checked network adapter drivers and are the same on both computers.
i've switched cables and they are ok
switched ports in the switch
switched ports in the pc-A (the motherboard has 2 ports) and for a brief period the bandwidth use boosted to equal PC-B, but then dropped down.

when you restart PC-A the same happens but then it drop again to a 6-7% use.

the two computer don't have the same software, PC-A as more software.

what i ask is, without formating PC-A and starting deinstalling programs is there a way to track down this problem? could it be from the software?



Thank you very much for your time.

 

[thiggins]

First thing I would do is to disable any firewall or anti-virus software in both machines.

You could also try using Process Monitor like I did in this article, to see if there is a difference in the block sizes used in the network transfers.

 

[olhorobot]

thanks!

PC-A had avg free installed PC-B didn't.

maybe it was that, gonna use the pc a little to see if it keeps the speed.

do you suggest a free antivirus that doesn't slow down the network?

the block sizes used seem kind of low to me, you can see it in this image

http://img9.imageshack.us/img9/9900/screenshotgum.jpg

 

[olhorobot]

after some use it is back to 7% of the bandwidth used

http://img9.imageshack.us/img9/7915/screenshotrst.jpg

 

[thiggins]

32 KB block size isn't unusual.

Check to see if any of the AVG processes are still running. You may need to uninstall it to make sure.

I use AVG myself and haven't seen any problem with it slowing down file transfers.
But I run only Resident Shield and don't run the email scanner or scan media files. I also don't run the MS Office scanners.

 

[olhorobot]

my last post was after i uninstalled avg and restarting, no processes of avg running and after restarting a few minutes ago the bandwidth dropped to 7%.

i'm thinking it will be very difficult to trace the problem, what's your oppinion thiggins?

thanks

 

[00Roush]

Looking at your Process Monitor trace I am going to guess you are running Vista.

Do you notice the same slowdown when copying to the server? Have you run a process trace on both PCs? Any sound or media playing at the time you are doing the coping?

You are doing a drag and drop copy correct? You mentioned opening a photoshop file so I am unsure if you are noticing the slow speeds inside photshop or just the drag and drop copy.

The interesting thing is that your Process Monitor trace has an icon next to the operation types of ReadFile and WriteFile whereas mine just has the words and no icon. Along with that you can clearly tell that the file copy is only doing one read then one write operation at a time. To my knowledge Vista usually keeps four read/write operations in flight at a time when doing a drag and drop file copy. This is what mine looks like...

Request sizes of 32k are used when Vista is communicating with a non SMB 2.0 server. (ie every OS except Vista and Server 2008) This size seems to offer good performance provided multiple read/write operations are in flight at one time.

00Roush

 

[olhorobot]

Any sound or media playing at the time you are doing the coping?

thank you 00Roush for this hint!

it's itunes that slow the connection when i play a music from local archive or when i listen to internet radios. i have to quit itunes from the bandwidth to come back to normal!

it also happens when i listen internet radios from firefox or even chrome!!!!

is this a known bug? any ideas?

thank you, you helped me to work faster

 

[00Roush]

Glad that helped. Yes it is a known problem and actually it is how Vista was designed to work.
Take a look at this thread for more information and how to fix it. http://forums.smallnetbuilder.com/showthread.php?t=899

Take a look at post #6.

00Roush

 

[olhorobot]

thank you 00Roush. i'll try your recomendation later

 

[olhorobot]

you were right 00Roush, now i can listen to music while working with large network files

thank you so much