If someone needs it:
Dell T5810 workstation modded bios with turbo hack and rebar enabled.
Only an external programmer can write to the flash chip (like cheap ch341b). The flash chip located under the blue end of pcie connector.
https://file.io/uUKLVYwwf9sl
DellT5810_Turbo_50_50_rebar.rom
This has been modified to all core turbo hack with xeon v3 cpu-s, added -50mv to vcore and imc for better turbo (all xeon cpu can handle it!)
The best cpu for this workstation is the 2696v3, 18 core, 3.8ghz all core turbo, or the 2699v3 18 core 3.6ghz all core turbo with this hack.
Only the v3 cpus works with this hack, not recommended to use v4 cpu with this modded bios! (early v3 or v4 ES cpus also not working, only the retail, oem, QS v3)
I dont know about the 46xxv3 series, probably works.
Also added Resizable bar feature enabled by default but needs to enable system configuration\memory map above 4g, and needs to disable CSM and legacy roms
After the flash run the exe file and set the rebar size (8gb works!)
https://github.com/xCuri0/ReBarUEFI/releases
https://github.com/xCuri0/ReBarUEFI/releases/download/0.3/ReBarState.exe