**Official DFI LanParty UT 790FX-M2R Review/Overclock/Guide Thread**

[Brother Esau]

What realy astonished me is that having an usb-memory stick plugged in results in ~6°C higher core and cpu temps in idle (not under load).

Well its just a Real Fact as it Happens when my Epson Printer is Turnned on the CPU Temps climb just as you are experiencing and have done so since the beginning with very early Bios

[justapost]

Well its just a Real Fact as it Happens when my Epson Printer is Turnned on the CPU Temps climb just as you are experiencing and have done so since the beginning with very early Bios

Crazy, that epson printer does not use power from the usb in opposite to the usb-stick. I tried a 4pin 12V rail instead of the 8pin one that helped in terms of power consumption. With the 8pin rail the consumption rose ~20W and with the 4pin only 5-10W if i remember correct. Gotta revise that sometime.
I assume this will also help in terms of temps but the cpu will be limited to 18A instead of 36A (only interesting above ~1.45V vcore).

[Brother Esau]

Crazy, that epson printer does not use power from the usb in opposite to the usb-stick. I tried a 4pin 12V rail instead of the 8pin one that helped in terms of power consumption. With the 8pin rail the consumption rose ~20W and with the 4pin only 5-10W if i remember correct. Gotta revise that sometime.
I assume this will also help in terms of temps but the cpu will be limited to 18A instead of 36A (only interesting above ~1.45V vcore).

I don't quite understand that myself Achim Perplexing it is

[DPeter]

Well its just a Real Fact as it Happens when my Epson Printer is Turnned on the CPU Temps climb just as you are experiencing and have done so since the beginning with very early Bios

Well Brother Esau I think I know the cause of that problem, some usb products really poll the bus many times causing the cpu to kick up out off low power (c2, c3, c4, other special mode) mode causing it to consume a lot more power! I first saw this on my centrino notebook, so i never use usb stuff on my notebook any more when I'm on the go (even changed to a pcmcia bluetooth card with dma so it would not excess te cpu for everything it needs). You can check this with windows performance measurment program and than select c1,c2,c3 enz percentage time. It will show a difference in these modes when popping up. I guesse you will see almost no c2 and c3 time when running the epson.

[Brother Esau]

Thanks for the Insight DPeter

[justapost]

Well Brother Esau I think I know the cause of that problem, some usb products really poll the bus many times causing the cpu to kick up out off low power (c2, c3, c4, other special mode) mode causing it to consume a lot more power! I first saw this on my centrino notebook, so i never use usb stuff on my notebook any more when I'm on the go (even changed to a pcmcia bluetooth card with dma so it would not excess te cpu for everything it needs). You can check this with windows performance measurment program and than select c1,c2,c3 enz percentage time. It will show a difference in these modes when popping up. I guesse you will see almost no c2 and c3 time when running the epson.

Well spotted.
I disabled EHCI (aka USB2) support in the bios and the core temps stay at 32°C now. The power consumption rises at about 2W thats what i get on other boards also.