Bought a self build mini itx build about a month ago:
i5 3550 ivy
ASUS P8H77-I (mini itx board)
Sapphire HD7850 GPU
2x4Corsair 1600 ram
Corsair Force GT 120gb
Silverstone sugo 07 (includes Bronze 80+ PSU)
Win 7 home 64
RAT3 wired mouse
Roccat arvo keyboard.
Wireless usb adapter (cannot hard wire network)
Basically, i built the system to play BF3 at low / med settings.
The build went very smoothly and all has been working very well, apart from one very annoying little issue. When playing BF3, or any game in fact, after about 10/15mins i start to get stutter which increases until the game is totally unplayable. exiting the game leaves my PC very stuttery and i have to reset to bring it all back to normal. All temps are well within limits. Mem test ok, CPU load test fine. I've turned off speedstep and C1E reporting. Also put windows in high power settings, and de parked the cores so they're all running all the time.
Using Latency monitor to check for the problem driver, "usbport.sys" is reported very, very high latency causing high system interrupts etc. everytime i move the mouse the latency flies up about 50 ms (or something like that?). With all USB devices unplugged (mouse/ keyboard / wireless) the usbport.sys latency is fine with no high counts racking up?
Funny thing is, If i use the USB3 ports (instead of USB2 ports) on the mobo for the keyboard and mouse I have no problems at all? At least, no stuttering and the system seems to run normally for ages without any slow down?
With keyboard / mouse in mobo USB2 ports I'm still getting the stutter problem. only played 10 mins but i could see the latency starting to creep up.
With the keyboard /mouse in the mobo USB3 ports I don't seem to have any problems? latency stays low. if fact, the usbport.sys reading stayed put...nothings connected to the usb ports!
BTW - i also have USB legacy support disabled. not that it made much difference being on or off?
If you haven't done so already you should upgrade the firmware to version 0409, it specifically includes USB stability improvements.
I highly recommend that you undo any other setting changes that you made, undo the power setting changes, core changes, turn USB support back on, turn speedstep on, turn C1E back on, etc... The defaults are perfect 99% of the time
Also, play on Ultra, your 7850 should handle it fine
ok, reset everything in windows and bios to default. nothing changed. I still get lots, and i mean lots, of irs and dpc if i use the usb2 ports for the mouse? using the usb3 ports alleviates the problem but i still don't think it's right as i still get lots of DPC's? It just seems that the usb3 driver handles the issue better?
would the rat3 high DPI be causing the problem? got the latest drivers and software installed.
Sorry, I got nothing. Maybe check and see if there's a chipset driver update and/or a firmware update for the USB controllers, sometimes they're separate. Take a look at your motherboard manual to see which port goes to which controller