The DirectStorage feature test produces three results.
- The bandwidth performance from storage to GPU memory with DirectStorage activated. The number represents the average bandwidth in gigabytes per second (GB/s) of game assets transferred using DirectStorage
- The bandwidth performance from storage to GPU memory with DirectStorage deactivated. The number shows the average bandwidth in gigabytes per second (GB/s) of game assets transferred using the standard Windows API.
- The difference in performance between DirectStorage on and off, expressed as a percentage
You can use the performance difference result, or compare the average bandwidth to see how the DirectX API's DirectStorage function affects performance. There are a number of sub-values from different parts of the system, from local storage - mostly SSDs - to the system RAM and VRAM. The DirectStorage feature test measures with and without the GDeflate compression, introduced with DirectStorage 1.1.
The following are the sub-tests from which the overall performance difference gets calculated:
- Storage to VRAM (measured with DS on + GDeflate vs. DS on + uncompressed assets vs. DS off no compression)
- Storage to RAM (DirectStorage on vs. off, each with uncompressed assets)
- RAM to VRAM (DS on + GDeflate vs. DS on + uncompressed assets vs. DS off no compression)
- GDeflate Decompression (the GDeflate Decompression Bandwidth)