Are those ztex boards?
Are you running at full speed with passive cooling?
I'd ideally like to run passively albeit with X6500s.
Yes, 1x3 and 4x3N, and it's not completely passive. You see that knob/sill under the edge of the windowboard, that's an outside air inlet. So I have air blowing onto the heatsinks.
They are running at 3x216 and 2x208.
I use a D510MO with SSD and PicoPSU as computer, so my whole digital setup is completely silent!
I think that without the active cooling they might run at maybe 3x208 and 2x200 instead, but the wear/lifetime would be very different.
We'll see how they run during the summer (if the balcony door or a window is open, there's no airflow) and if there is a problem I'll add some kind of active cooling.