Still I agree the airflow seems .... inefficient (I am trying to be more nice).
Hi D&T,
Can you arrange the boards within the enclosure to make the airflow more efficient and share it with BFL?
Thanks,
gigavps
Without access to the boards and some testing it is hard to say for sure. Maybe their design is optimal but it would seem to be. Even non-optimal maybe the design has enough airflow to keep everything coo.
If I purchase a mini-rig the first thing I would do it open it up.
I actually had little interest in the rig or mini-rig until finding out it looks like the boards are independent. Hopefully BFL can confirm that.
BFL can the boards function removed from the rig box and connected to a host PC via USB just like the single's do? If they boards can operate independently and they allowed pre-ordering with a deposit (say $2K) I would order today but I don't like locking up $15K on a product which hasn't even been built yet and some questions remain.
The first though I had when looking at the CAD is the 18 individual fans are counter productive to the airflow going across the boards. I would experiment by turning all the board on their sides and using pusher and puller fans to try and force airflow front to back. Maybe my time in datacenters is causing tunnel vision but that type of design allows multicore database servers to remain cool under higher load. Cold air in the front, hot air out the back.
The heatsink chosen is non-optimal for that kind of airflow but it still may work depending on heat load. Preferably one would want a heat sink with has large number of fins aligned with the direction of airflow so cooling is achieved by pushing airflow across the finds.
Something like (top view)
Airflow Airflow Airflow
| | |
| | |
V V V
[120mm FAN] [120mm FAN] [120mm FAN]
B B B B B B
B B B B B B
[120mm FAN] [120mm FAN] [120mm FAN] <- may not need this row requires testing
B B B B B B
B B B B B B
[120mm FAN] [120mm FAN] [120mm FAN]
B B B B B B
B B B B B B
[120mm FAN] [120mm FAN] [120mm FAN]
B = one board placed perpendicular. View is top view so you are looking at the sides of the boards.
B
3 ranks of 6 boards = 18 boards (although no room for expansion).
You would want a baffle or shroud to force the air past the heatsinks. So the exact layout would require some testing, experimentation.
I would imagine you could fit it in a standard 19" rack chassis. Maybe 4U?. I wouldn't put 10 in a datacenter rack but maybe 8 with 1U between servers. 200GH/s per rack?
Anyways that was my first thought.