3.8ghz@1.536vcore, my Biostar A770e3 started to have choke whine when the mosfets approached 100*C (the max limit, I quickly turned it off, biostar says 90*C long term causes pcb browning).
It was quite audible, i thought it was my whining blademasters at first. The whining goes away almost immediately when I stop prime95, and it only starts to whine after a few minutes of p95 at 3.8/1.536 when the VRM start to approach 100*C.
Now the temperature sensor in question, it's placed onto the topmost of the 3 in the 3+1 phase (in between the top and middle of the 3, more towards the top mosfet chips though), but it also might be reading the choke because the sensor is sort of pushing against the choke. Here's a pic of the NZXT Sentry 2 discrete temperature sensors:
The diode tip is underneath my custom VRM heatsink (took an am2 stock heatsink, sawed it into 1cm wide, stuck it onto my mosfets, put a 40mm fan onto it by screwing into the fins), but as you can see like the wires are sort of exposed going towards the tip, and they are pushed against the choke.
Like... i\l (vrm choke, the sensor, heatsink, if that makes sense visually).
I'm not sure if the diode is picking up the actual mosfets, or if it's picking up on the choke, but given the choke whine I'm getting, I don't think it's a good sign.I'm pretty sure it's choke temp because I've never had anything like this before, i think i only started registering such temps when i put this diode by the top phase and maybe it's like against the choke, or it could just be the hottest (i always thought the middle one was the hottest though). I dont get such choke whine on 3.7/1.504vcore.
It ran p95 blend for an hour, so I think I'll just stick with this 3.8ghz@1.536vcore, but not 24 hour test it due to this (in gaming/streaming i dont think it'll reach the same load and same temps, if it does ill shut it down and downclock/downvolt to 3.7ghz/1.504vcore, which is 24 hour stable).
I also dont know if my VRM heatsink is working properly, i mean it feels very warm to the touch, almost hot, but i can hold my fingers on it and 90-100*C should be untouchable and scolding hot, even 70-80 should be which is what my other mosfet diode is reading and what I've usually gotten. So it's doing something but not everything, maybe if I got some enzotech's they'd help dissipate heat better (although im worried it might not, after all this custom heatsink is like 40mm tall, whereas enzotechs have much less surface area). Or maybe it feels so much cooler to the touch because of it's relatively large surface area, ie its 70-80 at the mosfet but at the end of the fins its much cooler.
Edited by Belial - 12/19/12 at 3:42pm
If nothing else, I bet they degrade much more rapidly than they should.
