USB for PCI-X for my PowerMac G5

August 6, 2007 9:26 PM

How can I add more USB 2.0 ports to my G5 PowerMac if it only takes PCI-X cards?

The PCI-Express card I got doesn't fit. Bah. I guess that was dumb.

Is there any way to add more internal USB ports? I'd rather not get a hub, as it's an extra power cord, an extra blinking-lights thing on my desk, and frankly, I feel like I should be able to make use of these empty card slots.

The only things I can find to put in them are ATA ports, network ports, and SCSI ports, none of which I have any use for.

Thanks, all.

posted by Plug Dub In to computers & internet (8 comments total)

a 3.3v pci card will work just fine in a pci-x slot.

of course, it will drop the speed of that pci-x channel down to pci speed. which could be vaguely annoying if other things (ethernet, drive controller etc.) are also on that channel. but generally newer machines provide separate pci-x channels per slot so this shouldn't be a problem.
posted by dorian at 9:34 PM on August 6, 2007

There's a Sonnet card with 3 USB ports that is working fine in my G5. I do not remember the exact model right now, but these guys sold it to me.
posted by omnidrew at 9:37 PM on August 6, 2007

How can I tell what voltage a card is? I've got an Adaptec USB2connect 5100 (not PCI Express after all), and there doesn't seem to be any such info listed on the website.

I do remember trying it and it not working though.

Well I will go on a search for a 3.3v card now. Thanks!
posted by Plug Dub In at 10:06 PM on August 6, 2007

most newer pci cards should be universal (3.3v/5v) if not simply 3.3v.

you can tell by where the key (notch) is -- on 3.3v it will be towards the back of the computer; 5v will be toward the front of the computer. universal will have both.

pci-x may not necessarily like all universal cards tho.
posted by dorian at 10:20 PM on August 6, 2007

Good to know. As long as I'm asking, are PCI cards generally Mac/PC ignorant? Many list Windows system requirements, but so do a lot of things that don't matter either way. In the past I've stuck with things that claim Mac compatibility, but do I need to?
posted by Plug Dub In at 10:31 PM on August 6, 2007

The card doesn't care what OS you run, and the OS might not care about the card, either, but there's no quick-and-dirty way to know. If you want to be certain and remain free of hassle, you should continue to stick to things that are specifically mac-compatible. Or, at the very least, do some googling before plunking down yer dough.
posted by TheNewWazoo at 6:04 AM on August 7, 2007

in general you only care if there are drivers for the card, for your specific os. (altho there are some cards e.g. graphics, certain network, storage controller ...basically things with onboard ROM, that may need a platform-specific version of the ROM loaded. this was more of a powerpc vs x86 issue, endianness etc. but I digress)

usb only has 3 basic chipset types, well more like standards (ohci or uhci for 1.1, and ehci for 2.0) so for most operating systems there will be built-in generic drivers that suffice. similarly firewire.
posted by dorian at 6:39 AM on August 7, 2007

On the subject of hubs, powered devices and a lot of low-power devices such as keyboards and mice work just fine in an unpowered hub.
posted by aeschenkarnos at 6:06 PM on August 7, 2007