Z420 to Z620 Motherboard Swap?

[lastmile77]

Are the Z420 and Z620 motherboards basically identical aside from the connection for the riser for the second CPU in the Z620?

i have a Z620 with a E5-1660 v2 CPU (with Z420 liquid cooler) and a Z420 that also has a V2 motherboard though I forget which CPU it has.

I plan to keep the Z620 as a single CPU system and focus on maximizing single-core performance. I prefer the Z620 case and am wondering if I could swap the Z420 motherboard into the Z620 case. The lack of the riser connection on the Z420 motherboard would let me install a longer PCIe card in the top slot. That connector really limits the use of that slot on the Z620 motherboard.

I could eventually pick up another Z620 case to hold the V2 Z620 motherboard and reinstall the second CPU riser I have (pulled after I bought the Z620 V2 board and upgraded the processor) to build a second system with more cores for rendering or video transcoding.

I will be running Windows 10 on the E5-1660 v2 system and will trying to get MacOS running on the other system. So I’ll be using different graphics cards, etc. based on compatibility with MacOS. 

[SDH]

Those two are built on the same motherboard "blank".  One minor difference is that the Z620 has two LOMs (LAN On Motherboard) chipsets, but the Z420 has only one.  That could be fixed with a piece of strong tape covering the extra network port hole on the Z620 case.

Another much more important difference is the absence on the Z420 of the self-centering 6-position memory cooling fans header built into the motherboard that the Z620 memory cooling shroud device plugs into.  That shroud has two separate small PWM fans centered over the two memory banks.  It is a better cooling solution than the stock memory cooling solution for the Z420, which uses a significantly different memory cooling scheme.  The Z420's rear bank is cooled by an active device comprised of a black plastic airflow guide with an integrated PWM controlled small fan.  The front bank can be cooled by an optional passive front airflow guide that many do not know exists.  The Z420 has a 4-pin motherboard header for its rear bank fan that the Z620 does not.  Thus, the fan cooling wiring is different by quite a bit.

There likely is more.... you can tell I thought about this too.  I rejected the idea of harvesting the 6-position device from a bad Z620 motherboard and transplanting it over to a Z420 motherboard.  These motherboards have multiple layers beneath what you see on the surface so you really never know the hidden wiring inside.

[lastmile77]

Thanks for the details. It sounds like a swap isn’t a good idea.