Hey mate,
Did you noticed fans issues before water-cooling your Vega FE? Did you implemented power table on air?
Furthermore... Do you plan to buy a Radeon VII, wait for Navi, or stick with your current GPU?
Hey there,
I had tried everything on air to make it silent, everything from repasting (Kryonaut, Noctua, Arctic MX4) to custom power tables, undervolting, etc....it just did not work. Vega is too hot and inneficient, but when you have a good cooler it has a lot of legs.
In terms of the stock cooler, I did not notice any of the "fluctuating" idle fans which many users have reported, it has always worked at normal fan speeds. On idle it was silent, but when you started pushing it, it would reach 95c on the hotspot (which is in the middle of the GPU and HBM2 transposer on the die) quickly and fans would hit 2500-3500RPM.
I think this fan speed issue was for Vega 64/56 users with stock coolers (The aluminium ones).
So I moved to a custom waterblock in a semi-open loop and wanted to keep both the GPU and CPU on separate loops. I just added push fans and ran Prime95/IntelBurnTest and GPU intensive tasks all at the same time for 8+ hours and the GPU hot spot hits around 56-60c max and the CPU hits ~65c max (non overclocked CPU). The fans do not spin up and annoy me and I'm loving it.
I can also add a second Vega FE to the loop if I see a good price since I have a 2nd waterblock.
Regarding Radeon VII, I think that would be a perfect setup for me. Hopefully my waterblock works with it and macOS supports it soon (with how things are with AMD + Apple, it will most likely happen).
I would be happy with a single Radeon VII for years. RTX2080 performance is more than enough for what I do, which is basically a 1080Ti.
Just remember that the Radeon VII is a hot card too, pretty much similar to the previous gen Vega, so even that 3 fan cooler they have on is not going to help alleviate all your concerns.
If you can get an AIO for your X299 CPU, I also suggest a water cooler for your Vega if you are not willing do a full open loop. I would avoid 120MM Rads for the GPU though (I think this is one of the reasons why people with Vega Watercooled stock are having issues since it's such a small radiator and a hot GPU), go with at least 240mm for the GPU (I prefer 280mm for GPU with push/pull so you can run at low RPMs and keep it cool). This also depends if your case has enough room for all these fans. My current Phanteks Evolv X, even though a big case, I ran out of room once I added 360mm top (push/pull) and 280mm front (push/pull)...pretty much only things I can add to it are SSDs, that's all.
Some companies like EKWB and Alphacool make Vega waterblocks with semi-closed loops. I'm pretty sure they will make Radeon VII plates when it becomes popular enough.