USB 3.0 *VERY* slow on P8Z77-V LK

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rtangwai

[H]ard|Gawd
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I am getting very poor performance on the USB 3.0 ports of my ASUS P8Z7-V LK motherboard in Windows 7 64-bit. Write speed is averaging 5mb/s on a USB 3.0 key (Kingston Datatraveler III 16GB). The same key on another computer hits over 30mb/s so it isn't the key. The write speed is the same using a USB 2.0 key, and the USB 3.0 key is writing at the same rate on a USB 2.0 port. I flashed the BIOS to the latest version (9.04) and loaded the latest drivers from ASUS's website for both the Asmedia and Intel controllers. I turned off my AV, no change. I changed the drive settings to Better Performance, still slow. Read speed seems to be good - 55mb/s on the Kingston, 20mb/s on the USB 2.0 key in the USB 3.0 ports. Any suggestions?
 
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My only guess would be a driver update but you did that. Did you uninstall the old drivers before you installed the new ones?
 
Tried putting new ones on top of the old ones, didn't work so I uninstalled and reinstalled the drivers. What really bothers me is that it affects write speed far more than read speed - if it was affecting both I'd simply assume it was running at USB 2.0 speeds but it's clear the read speed is faster than USB 2.0 is capable of so that theory is out. I checked with Kingston, write speed is 30mb/s read is 50mb/s so I doubt it's the key itself - I have 2 identical keys and they both exhibit this. I tried reformatting the keys (NTFS, FAT, FAT32, EXFAT), same problem. I use Avast - is it possible that the AV is ignoring my command to suspend filechecking on USB devices? I don't load AI Suite, could there be something I'm missing from that software package that could affect write speed but not read?
 
I have both the ASMedia XHCI Controller (although I have only 1 listed) and the Intel(R) USB 3.0 eXtensible Host Controller in Device Manager.

I have tried plugging the key in both the I/O panel ports of the motherboard and the case ports (I upgraded the USB ports on my Raven RV02 to USB 3.0), same results.

USB 3.0 legacy is disabled, Intel xCHI is set to Smart Auto.
 
I tried installing ASMedia a second time, nothing happened nothing changed. I have reinstalled the 9.3 chipset driver, nothing changed. My upgraded USB 3.0 ports plug into the 20 pin connector on the motherboard, it should be noted *ALL* the USB ports (Intel and ASMedia) are affected.
 
Thats very strange indeed.
(Fwiw I personally would never use a case port for USB 3)
My Z77 mobo is a V Pro, maybe I have more ASM ports
I might mention piling on the vidcards steals bandwidth from USB 3.0
You might look at trying one card for a test.

There are a bunch of oroms in every bios update (incl USB)
So you may have a ever so slightly corrupted bios
I would use the CodeRush FTK tool to redo the bios
Really fixes things you wouldnt expect
Do not forget an unplugged PSU CMOS reset after flash
http://hardforum.com/showthread.php?t=1726429
Then i would look for misaligned pins in the grid
I assume you are not using USB 3 boost with AU Suite II?
 
I know this is an old topic, but it still shows up in search engines for those troubleshooting USB 3.0 issues on this motherboard.

I did my own research, and discovered which USB 3.0 ports in the back are connected to the Intel Z77 chipset, and which are connected to the ASMedia chip. When looking at the back of the motherboard, the two ports to the left are Intel, and the two ports to the right (closer to the audio ports) are ASMedia. Image: https://drive.google.com/uc?id=0B6KKJ-gY8SIJN2hfU1hxTVVoem8

This motherboard has separate drivers to install for each, and the ASMedia ports can be disabled in the BIOS. The ASMedia ports are a little wonky for legacy support, so don't use them for your keyboard and mouse, or to boot USB flash drives.

I hope this helps someone in the future who's searching for this like I did. :)
 

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We have P8Z77-V Deluxe. Same issue. Tried same solutions. No USB transfer speed above 2.7mb/s after initial burst. Grinds away hoping you'll get bored and fall lose interest.
What is hold this thing back?
 
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