Are all DVI-HDMI Cords backwards compatable?

I know HDMI and DVI are pretty much the same technology. So I assumed all cords would be backwards compatible - are they?

When I backwards compatible, I mean: The cords can transmit video from the video source to the end unit with the "end plug" (ends up connecting to the tv) being either HDMI or DVI.

I bought 3 dvi-hdmi cords and all 3 do not seem to transmit picture from my desktop to all 6 monitors. I have gotten all 6 to work just fine in the past but on my new setup I am not able to - but with the new cords.

My old dvi-hdmi cords worked just fine but in this scenario I need longer cords to reach my monitors.

I am trying to mainly use 2* R9 270's (non sli) to run all 6 monitors. In the past I ran all 6 monitors with just my ASUS EAH6670 1GB + AMD APU + 1* R9 270 - yes 3 different cards and 3 different drivers - so this is not really new to me. I know it is not an issue with my active DP to DVI adapters as I have tested both and I would assume I should get 4 monitors to work if it was a xfire issue or along those lines as I am using 2 "regular" ports and 2 DP (as I am running 3 monitors each card - each via 1* HDMI + 1* DVI to HDMI + 1* DP to DVI to HDMI). When I have everything attached, I can see the monitors available in windows display option but am not able to get a picture on the screens themselves.

You do not have to try to solve my problem with the monitors, but I am looking more so for the answer of the backwards compatibility. I simply put my problems to explain why I am asking, as I saw a vendor advertising backward compatibility and was wondering if this was just a marketing gimmick or an actual thing.

Thanks

For HDMI, it is all the same. For DVI, make sure it has the pin variation you want.

thideras said:

For HDMI, it is all the same. For DVI, make sure it has the pin variation you want.

Click to expand...

That is what I thought. I was just trying DVI-D.