Summary
DirectX 12 has introduced a new feature called GPU Upload Heaps, which allows the CPU and GPU to access VRAM simultaneously. This feature, in conjunction with Resizable-BAR, can increase performance in DX12 titles and decrease system RAM utilization by reducing the need to copy data from the CPU to the GPU. This article explores the implications of GPU Upload Heaps and how it can benefit gamers and developers.
Understanding GPU Upload Heaps
GPU Upload Heaps is a new feature in DirectX 12 that enables the CPU to have direct, simultaneous access to GPU memory. This feature is built on top of Resizable-BAR, which allows Windows to manage GPU VRAM directly. With GPU Upload Heaps, the CPU no longer needs to keep copies of data on both system RAM and GPU VRAM to interact with it, reducing data transfers and potentially improving performance.
How GPU Upload Heaps Works
GPU Upload Heaps works by allowing the CPU to access GPU memory directly, eliminating the need to copy data from the CPU to the GPU. This is achieved through the use of Resizable-BAR, which enables Windows to manage GPU VRAM directly. The CPU can then access the GPU memory using the GPU Upload Heaps feature, reducing the need for data transfers and potentially improving performance.
Benefits of GPU Upload Heaps
The benefits of GPU Upload Heaps include:
- Improved Performance: By reducing the need for data transfers, GPU Upload Heaps can improve performance in DX12 titles.
- Reduced System RAM Utilization: With GPU Upload Heaps, the CPU no longer needs to keep copies of data on both system RAM and GPU VRAM, reducing system RAM utilization.
- Latency Improvement: GPU video memory is very fast, so there should be no latency penalties for leaving data on the GPU alone. In fact, there will probably be a latency improvement with CPU access times on high-end GPUs with high-speed video memory.
Requirements for GPU Upload Heaps
To use GPU Upload Heaps, gamers need Resizable-Bar or Smart Access Memory support on both their CPU and GPU. Developers need to use the latest drivers from Nvidia, Intel, or AMD that support GPU Upload Heaps.
Developer Support
GPU Upload Heaps is already supported by Nvidia, Intel, and AMD drivers. For example, it’s already included in Nvidia’s latest Game Ready and Studio Drivers (version 531.41 or newer) and Intel A-series/Xe GPUs (with driver 31.0.101.4255 or newer). For AMD GPUs, developers must consult their AMD alliance manager to get a supported driver.
Implications for Gamers and Developers
The introduction of GPU Upload Heaps has significant implications for both gamers and developers. For gamers, it means potentially improved performance and reduced system RAM utilization. For developers, it means they can create more efficient and performant games by reducing the need for data transfers.
Gamers
For gamers, GPU Upload Heaps can improve performance in DX12 titles and reduce system RAM utilization. This means that gamers can enjoy smoother and more responsive gameplay, especially in games that require large amounts of data to be transferred between the CPU and GPU.
Developers
For developers, GPU Upload Heaps provides a new tool to create more efficient and performant games. By reducing the need for data transfers, developers can create games that are more responsive and smoother, providing a better gaming experience for players.
Table: Comparison of GPU Upload Heaps and Traditional Data Transfer Methods
| Feature | GPU Upload Heaps | Traditional Data Transfer Methods |
|---|---|---|
| Data Transfer | Reduces the need for data transfers between CPU and GPU | Requires data to be copied from CPU to GPU |
| Performance | Potentially improves performance in DX12 titles | Can result in slower performance due to data transfers |
| System RAM Utilization | Reduces system RAM utilization | Requires more system RAM to store data |
| Latency | Improves latency with CPU access times on high-end GPUs | Can result in latency penalties due to data transfers |
Table: Requirements for GPU Upload Heaps
| Component | Requirement |
|---|---|
| CPU | Resizable-Bar or Smart Access Memory support |
| GPU | Resizable-Bar or Smart Access Memory support |
| Drivers | Latest drivers from Nvidia, Intel, or AMD that support GPU Upload Heaps |
Conclusion
GPU Upload Heaps is a significant feature in DirectX 12 that allows the CPU and GPU to access VRAM simultaneously. This feature has the potential to improve performance in DX12 titles and reduce system RAM utilization, making it a valuable tool for both gamers and developers. As developers begin to implement GPU Upload Heaps in their games, we can expect to see improved performance and a better gaming experience for players.