Interna HD speed slows when other USB dev connected

[Franco]

I have spent the whole day wondering why my internal HDs are so slow and I
found why - but not how to solve it.

Mobo ASUS A8V-MX, 1 SATA HD internal , 3 IDE HD internal , 1 IDE internal
DVD, 8 USB ports enable on the MOBO, 1 G DRAM, etc

XP Pro SP2, latest MOBO BIOS, all latest drivers for everithing, clean
install. ALl HDs run in Ultra DMA ( no PIO, no failure ).

Using a HD transfer speed tool I can see my SATA Maxtor runs at 68 MB/s,
quite good. Also the rest is running as expected in IDE 133

If I just plu an USB key into on of the USB ports on the MOBO and I run the
Internal HD transfer speed test, the HD speed is max 40 MB/s. If I plug for
example the USB key into the USB port of an installed PCI to USB card, the
speed is even slower, down to 20 MB/s if the card is in PCI slot 1 and down
to 5 MB/s is the card is in PCI Slot 2!!

To summarize: internal devices work fine , but just plug anything to USB (
even if you do not use it ) and performances drop !

Anyone seen this?

I also bought a Compaq Laptop with Vista Basic in it and this kind of
behaviour is not there

Thanks in advance

Franco - Italy

 

[Andrew E.]

Check youre power supply specs,it may be maxed out or worn out with 4 hds
running at 1 time..With 4 hds + other hardware,you need to have at least
450 to 500 watt ps..

 

[Franco]

Thanks Andrew, I did check, and it' s a 370 W and for that reason I opened
the PC, unplugged all the other HDDs and tested it with only thw SATA HD,
same beahviour....

Also all external devices are powerd separately..

Any other hint?

Thanks

F

 

[Anna]

Check youre power supply specs,it may be maxed out or worn out with 4 hds
running at 1 time..With 4 hds + other hardware,you need to have at least
450 to 500 watt ps..

Thanks Andrew, I did check, and it' s a 370 W and for that reason I opened
the PC, unplugged all the other HDDs and tested it with only thw SATA HD,
same beahviour....

Also all external devices are powerd separately..
Any other hint?
Thanks
F

Franco:
While we have found from time-to-time a slight falling off of data transfer
speeds of HDDs (usually PATA/IDE types) when USB devices (particularly USB
external HDDs) are connected to USB PCI cards, we've never found anything as
significant as what you're reporting. In virtually every case I can recall
in "real-life" terms the speed difference was so slight as to be
inconsequential. So I really don't know what's at the root of your problem.
I cannot conceive that the problem might lie with an underpowered power
supply.

However...

Your ASUS board has 8 USB 2.0 ports, does it not? Is there really any need
for you to install USB PCI cards in your machine? Are you really running
more than 8 USB devices at one time?
Anna

 

[Paul]

Thanks Andrew, I did check, and it' s a 370 W and for that reason I opened
the PC, unplugged all the other HDDs and tested it with only thw SATA HD,
same beahviour....

Also all external devices are powerd separately..

Any other hint?

Thanks

F

The chipset may have several operating options in the BIOS.
You may be using a mode, where the driver is defective.

SATA, AHCI, RAID

It could be that different drivers are used with each.

With the SATA option, does the default Microsoft driver work ?

Could the bug be in the AHCI driver from VIA (if that is what
is being used) ?

I would experiment with the possible disk operating modes,
and see if there is a difference.

Similar symptoms, so probably not a busted motherboard. (links for old and new forums)
http://web.archive.org/web/20060813...iew.aspx?catid=6&threadid=73507&enterthread=y
http://www.tkarena.com/forums/general-pc-help-arena/28570-usb-devices-slow-down-my-harddisks.html

My guess is, avoid AHCI if that is what you're using.
http://www.tkarena.com/forums/ide-sata-raid-arena/28957-vt8251-success.html

Paul

 

[Franco]

Thank you All, I will be a few days off for work and when I come back mid
week I will check your suggestions out and let you know

Thanks again

Franco