DELL Optiplex 780 desktop PCI Express add on card

According to the manual, the PCIe x16 slot is disabled when you connect a monitor to the onboard video connector. So you can't use that slot for anything other than a video card.

If you want to install some other type of card, you have to use one that fits in a PCI slot because that's the only other type of slot that's available in the desktop version of the 780, according to the manual, and it has to be a low profile PCI card unless you have the card riser. With the riser you can use a full height PCI card.

Well, all I can say is the guide must be incorrect. :emotion-10:

The desktop doesn't have any PCI-e slots other than the X16 video slot so you can't use any other PCI-e card in the desktop, even thought the mini-tower has an available x1 PCI-e slot.

And you've confirmed that a PCI-e x16 video card works in your slot, but the other card doesn't.

I'll point this out to my Dell tech contacts and see what they have to say about this contradiction. :emotion-5:

The computer however identifies it as unknown PCI serial port.

Then it sounds like the PCI-e slot is working. You just need to find the right driver for your OS.

I see 3 different ones on Downloads Tab.

One should work.

http://www.sybausa.com/productInfo.php?iid=1229

SYBA USB 3 card works fine on another computer (I know what drivers it required).

Are both computers running 64-BIT  ... Windows-7 ?

I would still try the other updated online drivers.

For now, don't connect the INTERNAL 20-pin cable (if available), but DO connect the Internal 4-pin Molex power.

Are both computers running 64-BIT  ... Windows-7 ?

For now, don't connect the INTERNAL 20-pin cable, but DO connect the Internal 4-pin Molex power.

pointed that the slot must be disabled when onboard video is used

Pretty sure this is just refering to the common practice of disabling one-or-the-other video devices.

Wouldn't make any sense to include (only one) PCIe x16 slot that can't be used for various Add-In cards.

Already done this, no difference.

That's what I expected.

If you still want to install a USB3 card, have a look at this one which fits in a PCI slot. Says it fits "small form factor computers" so it might even fit your desktop 780 without the riser card that's required for full-height add-in cards.

And I heard back that one of the Dell tech people is going to look into the inconsistency in the manual vs. tech sheet, but I don't think that's going to help your issue.

If you still want to install a USB3 card, have a look at this one which fits in a PCI slot. Says it fits "small form factor computers" so it might even fit your desktop 780 without the riser card that's required for full-height add-in cards.

I've yet to get close to USB3 rated speeds on a brand new PC with native USB3 slots. Best I've ever done with USB3 external hard drive is ~3.5 - 4x faster than a standard USB2 stick in the same slot.

I cannot believe that in such popular model, which is on the market for at least 4 years, no one was tried to install a pcie expansion card and DELL still has info of such card availability in their literature.

You'd be surprised... :emotion-3:

Hey Guys,

I have the DELL Optiplex 780, and I was worried if I could use two Firewire cards (IEEE1394a) at the same time using PCI and PCIE slots. I had the PCI to IEEE1394a card earlier.  I purchased PCIE to IEEE1394a card today and I was able to use the both cards successfully as I checked by loading two cameras connected to the cards  through firewire cables.

So at least PCIE  slot works fine for using IEEE1394 in the DELL computer.

Good luck