I'm going to base my answer on the Aspire M5800 series.
If you're able to provide a part number for the system, I can verify the model.
Based on your post, you're looking at installing a SATA 3 PCI card and not a SATA 3 PCI Express card, is that correct?
Specifications for the Aspire M5800 system indicate the following slots:
1x PCI Express Slot Type: x16
1x PCI Express Slot Type: x1
2x PCI Slot Type: x1
Just in case, the PCI Express slots are 1.1 and not 2.0.
Hope this helps.
Important Links: Global Support Pages | Knowledge Base Articles Remember to mark posts that resolved your issue with Accept as Solution. You can even mark multiple posts in a single thread. This will make it easier for others to find the same information. Use the Give Kudos button to offer a thumbs-up for good post content and a pat on the back to the author.
I have the same Acer EG43M mobo in my M5800, I'm wondering what I need to know for compatability issues when I'm upgrading the video card? I know the pci-e slot is 16 pin, but SATA 3 is that the power input for the card to plug into? I want to put a gtx 560 or 660 in to this pc, since the 2.0 cards are backwards compatable it will work I'm hoping..
Member RevoMaxx is quickly moving up the ranks of Acer Community. He joined us in September and is already making a difference. It's great to see new members like him make a difference only after a few months. Thanks RevoMaxx!