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question about usb powered devices

by mko / July 11, 2005 9:05 AM PDT

if a device, a portable hd, is usb powered, will the main power supply affect its performance? say,,,if the power supply is 320watts(which btw was not enough to get "full use" of my nvidia card),,,will the lack of more wattage affect the speed of the usb powered hd?

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by Yew / July 11, 2005 9:27 AM PDT

An external HDD would require it's own power source apart from that delivered by the USB bus (which is pretty low power). I have an external enclosure for one of my old HDDs, and it has its own power inverter.

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by John.Wilkinson / July 11, 2005 10:51 AM PDT

Most external hard drives require more power than a USB port could ever provide, so they have their own external power source. Recently mini portable HDs became available which are powered solely by their USB connection. These devices took a while to debut because a USB port can only provide 2.5W...that's right, 2.5W. (Click here for more information.) Because the wattage is so low, PSU's barely flinch when you plug them in. However, since you said that yours is already maxed out, you'll have to make sure that you only use the portable HD during periods where your other components are not pulling juice rapidly. Otherwise you won't have enough power for all your devices and something will'll want to be making that choice, not your computer.

Hope this helps,

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Not suppose to
by Willy / July 11, 2005 11:54 AM PDT

It's not suppose to, but you never know if you're at the edge, it may. In other words if you're at the theshold, maybe but it's a "go, no go" situation. Devcies that are ext. powered tend to not push the USB ports, though the data signals are 100%. Those that use USB as a power source can place some stress as only a marginal power is available and a finite amount is present for all devices. Thus, when one starts to act flaky it may effect others.

As for your video card, I suggest at least 350W or better, more like 400W and a decent brandname at that.

tada -----Willy Happy

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