I recently purchased a gtx 1070 from a gtx 950...however when I went to go plug my dvi cable in, it didn't fit! I own a Asus 27in monitor if that makes it easier. Is there someplace I can buy a new cable to fit it?
A different cable. The one you have probably has the analog pins needed to make DVI-I work. You can either pull the analog pins out yourself, or just get a DVI-D cable.
According to the nVidia forums a 10 series card (at least reference card) has only DVI-D (exclusively digital). Your old card may have had DVI-I (which supports analog as well as native digital signals).
A different cable. The one you have probably has the analog pins needed to make DVI-I work. You can either pull the analog pins out yourself, or just get a DVI-D cable.
Motherboard doesn't matter, not sure why he asked about that.
Look at the horizontal "flat blade" part of the DVI cable. I'm guessing there are four pins around it, two on top and bottom. Those are the part that carries the analog signal in a DVI-I (or DVI-A) cable. If you have a DVI-D port which has been suggested then there isn't a part on the GPU for those four pins to go in. They are hitting solid plastic and prevent the cable from being used. You can pull those four pins out with pliers, get a DVI-I to DVI-D adapter, or just go ahead and buy a new DVI-D cord.