• ×
    Windows update impacting certain printer icons and names. Microsoft is working on a solution.
    Click here to learn more
    Need Windows 11 help?
    Check documents on compatibility, FAQs, upgrade information and available fixes.
    Windows 11 Support Center.
  • post a message
  • ×
    Windows update impacting certain printer icons and names. Microsoft is working on a solution.
    Click here to learn more
    Need Windows 11 help?
    Check documents on compatibility, FAQs, upgrade information and available fixes.
    Windows 11 Support Center.
  • post a message
We have new content about Hotkey issue, Click here to check it out!
HP Recommended
Microsoft Windows 10 (64-bit)

HP Z820

USB 3.0 Ports (Front & Rear) are working but at very slow speed !

Help please... 

HP Recommended

help, i have a blue chevy thats slow, please help


i've given you just as much information as you have about your usb issue, do you think you can figure out what's wrong based on my provided info? most likely not.................


we can only give help when the poster actually provides some specific information


such as:


usb slow: hmmm what's slow? without any xfer numbers we have no reference, what you consider slow may be normal


what hardware is connected to the z820 usb port? connecting a usb 2.0 device to a usb 3.0 port will give........usb 2 speeds


are you actually connecting to a z820 usb 3 port? the z820 has both usb2 and usb 3 ports on the front with the usb 3 being blue, and usb 2 black in color


what file/files are you copying and is the system doing other tasks?


does device manager show any red "x" or yellow "!"

HP Recommended

I'm aware USB3 is blue and USB2 is black 😂 and of course I'm connecting a USB3 device to USB3 (which is blue) tried front and rear ports same slow speed, OK numbers : USB3 Eternal SSD connected to USB3 (blue colour) port giving around 22MB/s !!!

Same USB3 EXternal SSD giving around 390-400 MB/s on iMac's USB3 Port.


To be more specific I'm using this: 





HP Recommended

first of all, both the mac and windows reporting of usb speeds are not accurate, and using apples to oranges is not a valid way to compare speeds..... a somewhat accurate method is to compare the actual time it takes to start/finish the exact same copy operation between the two different systems


next, you need to keep in mind the "CONNECT" speed has nothing whatsoever to do with the actual data xferspeed the connect speed is simply the MAX speed you might get not what you actually are able to get and both systems shown data xfer speeds are very rough approximations


next, the type of data being copied/moved has a major effect on the actual data speeds lots of small files will take longer than a several larger files


now as to "your" SPECIFIC hardware setup regarding data speeds


1. the ATOM USB device you reference is a USB 3.1 (GEN 2) device that has a 10Gb/s max speed, this is double the speed of USB 3.0/3.1 (GEN 1) which has a 5Gb/s max speed


2. the HP z820 is a usb 3.0 port with a 5 Gb/s max speed


3 the iMac is most likely using a usb 3.1 GEN 2 if it's a late model iMac



HP Recommended

please tell all facts and did some)

  • SLOW COMPARED TO WHAT.? DAH MAC,  but yes. is slow. and then more the URL
  • : USB3 Eternal SSD connected to USB3 (blue color jacks) port giving around 22MB/s !!! 
  • NO SSD told, it or the whole drive told as sold no, maker and model and all that.(url to yours is?)
  • YES 22mB/s IS  SLOW. you do know that 22MB/s is 220Mb/s same right, B = bytes , and b = bits right ?
  • Device manager  must be  w10 shows all USB ports as healthy?????
  • I have USB-c drive external with fastest  HDD on earth inside, seagate 3.5" 6TB. that does. 200MB/s  B= BYTES
  • I say that only to prove yours should beat mine easy.
  • same dock/enclosure like  USB-c and a good SSD drive, can do 500. easy. (the top bench mark site show them all)
  • USB3.0-SS is (625 MB/s) megabytes per second, or 10x that expressed as bits. (raw speed not actual through put)
  • my guess is your USB 3 driver is missing ,dead , wrong or corrupted, get the right one from HP only.

the chip in the enclosure matters to, that is why I use USB-c chips end to end, for max speed. drive too.

HP chip >>>> enclosure chip,  and >>>> drive speed SATA6 rated) SSD.

if anything  in this SERIAL path is slow that is what you get and for sure wrong PC driver.

your ATOM SSD:

lightning fast with speeds up to 560 MB/s and equipped with the latest USB-C (3.1, Gen 2) connection-


I do not know what chip is inside the mobo if this PC, HP is quite in all specs there but is not the C602

if we did know the all this goes far better what it really  can do.

makers name on chip and chip model.

what I do is look on the MOBO with eyes.

Nuvoton NPCD379H = Super I/O controller,  a secret chip , contract, and unknown in the world.

if true that makes answers impossible but do load the correct driver, for sure custom chips like this from HP.

or it will never work full speed.



NO warranty answers by me.
HP Recommended

once the driver is loaded


you can do USB3 loop back tests 2 ways

1: hardware


2; pure software , using 2 PCs and to apps that measure speed, same as I do with sublan tests .

run this app, free and safe , speed tests.

my ram disk shows 7800 MB/s   and expected. 

they have 5 million  benchmarks there.

one trick is testing any HDD and only uses its cache ram for speed, not actually slow hDD.

this tells you fast if the USB port is working using that trick

to do that trick takes benchmarks smart enough to do that,. most are not.



NO warranty answers by me.
HP Recommended

- Yes, ATOM USB SSD is a USB 3.1 (GEN 2) device  

- Z820 USB3 port should be able to go up to 625 MB/s but it's showing about  22 MB/s max !!!

- Same ATOM USB SSD on iMac (which also has USB3 ports) is showing around 390-400 MB/s 

- as per my understanding USB3 supports up to 625 MB/s


Do I need USB3 drivers?

Where can I find it? Any links?

HP Recommended

I told you 2 things

1: the USB3 chip is HP custom chip

2: and for sure needs the HP driver to make that work

is the failing PC internet connected, and if yes unistall  the USB 3 driver then put it back using device manager?>

yes, go to hp.com

go to your HP Z820 support page

then load the all chip drivers there. for w10.

think of a horse  with no saddle (driver software) AND You can not ride fast.

yes you need working driver yes, for SURE.

some PCs with split chip sets,  for  example this PC has no USB3 ports in the south bridge

HP had to add one, but did no choose a common normal USB3 chip they contract ordered one that nobody else has.

if you used HWinfo32.exe and read its screen and told me, the chips Vender code and DEVID code

id look it up in MS driver catalog servers data base, and see if it is even there.

here is me doing just that, for a nvidia chip




SEE we are not blind to PnP at all. see?


NO warranty answers by me.
HP Recommended

the usb 3.0 chip on the z820 motherboard is a generic TI 7340 chip and it's far from custom, it's a off the shelf part available to anyone and this driver is part of the default windows 8.1/10 included drivers and this included driver is the same as the one on the MS site (although newer updated drivers are available for download from several usb venders)




next the usb 3 max speed issue,  5Gbps (625MB/s) is the absolute theoretical maximum speed and does not take into account real world data transmission overhead (such as checksum packets), and less than perfect data connections wires and software overhead







and one last thing, do not confuse Mb/s with MB/s as MB/s is approx 8 times faster than Mb/s




HP Recommended


Front USB 3 AJA Speed R & W: 28 MB/s

Rear USB 3 AJA Speed R: 295 MB/s W: 189 MB/s

† The opinions expressed above are the personal opinions of the authors, not of HP. By using this site, you accept the <a href="https://www8.hp.com/us/en/terms-of-use.html" class="udrlinesmall">Terms of Use</a> and <a href="/t5/custom/page/page-id/hp.rulespage" class="udrlinesmall"> Rules of Participation</a>.