V4 won't work with this all core turbo mod. As for the V3 I believe the 2696v3/2699v3 will get you the highest overclock speed of about 3.9ghz on all cores. I believe I saw that that chip has 38 multipliers so you would only need to push your bclk to 102.6mhz to get 3.9ghz.
I am currently running 2667v3 which has 36 multipliers and I am able to get 3.8ghz overclocked with a bclk of 105.6. Which is pushing my motherboard's stability -- for this use
@kjboughton's base driver without voltage offset. Else you will have stability issues. He and I are both running on the Asus z10pe-d8 ws. It's a solid motherboard.
I am currently using this for work and gaming and I do find that with 1080ti SLI, you will still have CPU bottleneck with 3440x1440 (
https://github.com/freecableguy/v3x4/releases/tag/v3x4-0.10b-i306f2-rc9). I don't know if the 3.9ghz or maybe even 4ghz (if that's doable) on the 2699/2696 would help SLI for gaming. If you're looking for a gaming rig, it's probably better to get a second hand i9-9740x or 9760x. Much higher oc capability.
It really does suck that the multiplier on these xeons are locked. I wish there was some hack to unlock them. I am pretty sure they can handle the oc.