VRM Heatsink on only one socket? (Foxconn/Inventec B800)

[Markess]

I just noticed something with a system I'd built around a Foxconn/Inventec B800. The second, rearmost, CPU (CPU 1) has a VRM heatsink, but the CPU at the "front" of the motherboard (CPU 0) does not. I couldn't find any info on Google, but found many images from resellers with the same set-up (see pic), so I don't necessarily think my board simply came with one missing.

Does anyone know of a reason why one socket would have a VRM heatsink, while the other doesn't? The only reason I can think of is that in the original Chenbro 1U chassis, the front socket got more airflow, so a heatsink was less necessary and would impede airflow to the second socket?

I'm changing up the usage on this box and was considering running it on only one CPU. If I do, am I better off swapping the heatsink over to the socket with a CPU? I wouldn't think the VRMs on the empty socket would be generating much heat?

Edit: I opened up my other dual processor system with front to back CPUs, A Supermicro X9DRT-F, and it has the same thing. So maybe its common to put heatsinks on the rearmost CPU only?

 

[111alan]

Yes, the absence of heatsink on cpu0 side is because of the placement of fans. On the contrary on most branded retail boards, since the manufacturers don't know the chassis configuration, both VRMs have heatsinks.

And the unused VRM will not generate heat in most situations. On recent intel motherboards PWM controllers need to communicate with the CPU when booting. From what I observed the VRM without a corresponding CPU will not start at all.

 

[Markess]

On the contrary on most branded retail boards, since the manufacturers don't know the chassis configuration, both VRMs have heatsinks.

That makes total sense. I was wondering why some did and some didn't. Thank you