If it's so common then why can't you provide a source? If it's as common as you say, it should be easy... But don't worry, I'll do some legwork as I like to provide information and state claims with supported references.
The release notes for AMD's driver 20.5.1 beta: https://www.amd.com/en/support/kb/release-notes/rn-rad-win-20-5-1-ghs-beta
Microsoft hasn't stated specifically which DirectX version this change applies to, so the graphics API used by each game may vary the scheduler API-to-API. It would be reasonable to conclude that all DirectX games used software scheduling prior to the introduction of this feature and setting. My point: NVIDIA has hardware scheduling on the GPU, on their driver, and Windows 10/11 supports the enablement of it. Therefore your claim: "Thread scheduling, AMD have hardware on the GPU's its self to handle that, Nvidia's is software, IE it runs on the CPU, so the CPU load is high on Nvidia cards, what one might call a "Driver Overhead" as a result a game that would be by its self heavy on the CPU would bottleneck an Nvidia GPU sooner than an AMD GPU given it doesn't use any CPU cycles just to drive its self." is false.
- Windows® May 2020 Update
- AMD is excited to provide beta support for Microsoft’s Graphics Hardware Scheduling feature. By moving scheduling responsibilities from software into hardware, this feature has the potential to improve GPU responsiveness and to allow additional innovation in GPU workload management in the future. This feature is available on Radeon RX 5600 and Radeon RX 5700 series graphics products.
This doesn't prove Nvidia has hardware thread scheduling or that my statement was false, its an AMD drive statement, the fact that testing still proves there is a higher CPU overhead, significantly so, on Nvidia hardware would indicate they still don't, at least not up to and including Ampere, don't know about Lovelace.
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