I have a Radeon HD 6670 with 8GB memory. I want to buy a monitor that has a resolution of 2560 x 1080. Will it work? That is a rather new resolution and the HD 6670 is an older card.
By DVI yes, if the monitor has a native DVI port, but you really should upgrade to a new video card with current support status and HDMI and DisplayPort capable of modern resolutions.