8104 and its USB ports - confirmation needed

Hi!


Can anyone confirmed that the right-hand side USB ports are supplying less output current than the one on the left?

I've tested with a 2.5" external OTG hdd and found that half-way through file transfer of a few GB using the right-hand side USB ports (with the fork-type USB cable that comes with the OTG hdd - 2 ports attached) the hdd just stopped. Whereas similar transfer using the left-hand side single USB port was smooth going.

This can either be that:-

a) the design of the 8104 USB ports are such that the right-hand side ports are supplying less than the left one. By how much?
b) faulty motherbord/USB ports if ALL ports are designed to give the same maximum current output

Any feedback? Thanks

Re

Hi DarthAcer,

Your quote

"If you go to device manager and expand Universal Serial Bus Controllers branch, you'll see 4 USB Root Hub items under it. Double click on any of them and check Power tab - it'll show if any devices are connected and how much power they consume."

Checked but can't find Power tab?


"For instance, external mouse (98mA typically) should be unplugged. Bluetooth should be off"

If you say that in the connecting of the OTG hard disk I must unplugged my mouse or turn off my bluetooth then I say it must be a design flaw. ACER should spell it out as a warning to its users somewhere, right? I doubt they would do so otherwise nobody would buy their 8104. BTW, which other brand(s) of notebook require this to be done?

Yesterday, I called our ACER tech support and they claimed that all USB ports come with same max. current output i.e. about 500mA. Now thats interesting. If all the ports give same max. current output then why am I having a problem?

Re

OK guys,


I just did some tests this morning before going down to ACER service centre.

Now, I was testing in my office using a 2.5" PLAIN (wihout LCD display type) hdd casing with a 40GB 4200rpm SAMSUNG drive which comes with a two-connector USB cable. Result is no problem from both left and right-side USB ports when I performed a transfer of about 3GB files.

I used my LCD display casing and a 80GB Hitachi 5400rpm drive and only the left-side USB port can perform without problem. Remember that the left-side USB port only requires one USB connector. The files transfer test on the right side failed despite using two USB ports for power supply for my three-connector USB cable.

At ACER service center I repeated the above tests with their 2.5" PLAIN (wihout LCD display type) hdd casing with a 40GB 4200rpm TOSHIBA drive which also comes with a two-connector USB cable. Result is also no problem for both left and right-side USB ports.

I also noticed at ACER that their 40GB 4200rpm HITACHI (1A) drive was having a higher current rating than that of their TOSHIBA (0.7A) one.

Then I noticed something interesting at ACER. During the files transfer the power display on my casing LCD was relatively stable. I then realized that I was using their older LITEON AC adaptor to perform the files transfer. I managed to successfully transfer files on the right-side ports for two of the three ports. The right-side port nearest to me failed the files transfer test. Using my original DELTA Electronics AC adaptor I only managed to successfully transfer files using the furtherest right-side port. The other two right-side ports failed the files transfer test.

Note that all files transfer tests using my OTG hdd at ACER were carried out using the same file folders totalling about 3GB in size and two right-side USB ports were utilized for adequate power supply to my OTG hdd.


SUMMARY

a) PLAIN 2.5" hdd casing with no LCD display type (which comes with a single cable with a male USB connector on each end) and a 4200rpm TOSHIBA or SAMSUNG hdd has no problem whatsoever

b) LCD-display type 2.5" OTG casing (which comes with a fork-type USB cable with 3 male connectors) with 5400rpm HITACHI hdd cannot be adequately powered by the right-side USB ports. I suppose HITACHI 5400rpm hdd and the LCD display consume greater power.

c) I think the stability of the AC power supply and the different AC adaptor used at ACER in some way contributed to the files transfer success.


So, to avoid the problem of inadequate power supply for large files transfer its advisable to get a 4200rpm hdd (other than that of HITACHI) that comes with lower current for use as external hdd. Until I change my hdd to either SAMSUNG or TOSHIBA type with lower current rating I'll be unable to confirm if the AC power stability and the power consumption by LCD-display does play a part.

Re

OK!


I bought a 2.5" 60GB 4200rpm TOSHIBA hdd (0.7A) and using the same LCD-display casing did the same files (about 3GB) transfer as above using all the USB ports.

No problem encountered for the left-side port.

Managed to transfer quite successfully using the right-side ports although sometimes transfer stopped halfway especially for the port nearest to me. Also, when I tested using power from the AC main with one outlet supply only (NOT with mutiple plugs to the same outlet) I get the transfer done smoothly.

Thus I concurs with DarthAcer that a stable AC supply is needed and that using a lower rpm hdd with brands like TOSHIBA (0.7A), SEAGATE (0.46A) or even SAMSUNG (OTHER than HITACHI which uses 1A) should enable satisfactory performance.

I also noticed that my OTG hdd casing says DC 5V 0.6A. I wonder if I'll to use SEAGATE (0.46A) 4200rpm hdd I'll get the best performance?