it draws air in through the back (and from its surroundings), and
it's 270mm long!
I took some measurements on my case. I have exactly 270mm of space from chassis-back to front-fan.
I had originally planned to cool my CPU using the CoolIT ECO ALC C240, placing the grill at the air intake in the front. However, installing it reduces the 270mm space to a 247mm space. Seeing the length of this, and other, graphic cards, I realized to my dismay that, without some drastic case modding, I would not fit the CPU cooling plus the graphics cards into the case.
I can re-obtain the full 270mm without case modding by downgrading my CPU cooling to a CoolIT ECO ALC C120. But I would prefer not to.
So, my question to you is
do you know of any rear-exhaust-ed HD 6950 card, with 2GB RAM, which preferrably has length <247mm, but can have at most length 270mm?
If this unboxer on YouTube is correct, then the XFX HD-695X-ZNDC should fit my requirements (except for excausting all air out the back, but as bystander mentioned, there is no card which does not).
He measured the PCB at 9.5''. This is ~242cm. Which is within my desired bounds. The listed length of the card is 259mm, which is less than my fallback bound. So worst-case scenario, I would need to replace my CPU heatsink.
Now, the XFX HD-695X-CDDC listed length is *even shorter*. This one has 2GB memory. Is this a good card?
If that is the dimensions, then it should work. I believe another card that is short is the MSI twin frozr II. I know it's shorter than the reference by a fair bit, but I don't know the exact dimensions.
With the sides, top and bottom completely sealed, there is only a hole in the rear (inside the case) for air intake, and a hole in the front (to outside the case) for air exhaust. Crossflow fans are quiet and efficient, and since the air intake is not on the top, you can put another PCI card right next to the graphics card without inpeding airflow, and you can easily directly channel air from the front of a case to the back of PCI cards. The manufacturers could even add another PCB to the case, along the top, in parallel with the PCB I drew, and let the two PCB share the same massive heat sink. The back of the card is just one big hole; all the connectors can either be put into different PCI card spaces in the case, or pulled out of the case by a cable (what difference does it make whether the cable is mounted to the card or to a cable attached to the card?).
edit: Where it says "PCI" in the drawing, I meant "PCI case mounting bracket". You know, that metal bar you fasten to the case using a screw, to fasten your card.