Microsoft’s DirectStorage API is claimed to deliver ultra-fast load times for PCs, similar to what Xbox series console and PlayStation 5 users have experienced for two years. With the first DirectStorage enabled games ready to launch, a benchmark test showed a real and significant performance boost on retail hardware.
Tests from PC Games Hardware show that Microsoft’s DirectStorage API can help NVMe SSDs load game material significantly faster than SATA SSDs. they also provide a huge advantage of GPU-based decompression over CPU decompression.
The site runs Microsoft’s publicly available Avocado loading DirectStorage demo on SATA SSDs, PCIe 3.0 NVMe SSDs, and PCIe 4.0 NVMe. It also compares decompression speeds between three GPUs and CPUs – AMD Radeon RX 7900 XT, Intel Arc A770, NVIDIA GeForce RTX 4080, and 5.2GHz Intel i9-12900K.
The chart below shows the transfer rates in GB/s for each hardware configuration, showing the average results across the five tests. Here, the NVMe SSD is several times faster than the SATA SSD, while PCIe 4.0 has a slight advantage over PCIe 3.0. Perhaps most curiously, the A770 outperforms the RX 7900 XT and 4080 in terms of GPU decompression, even though it is the underdog in terms of gaming performance.
The screenshots in the demo show the difference between CPU and GPU decompression. Some screenshots show several gigabytes of material taking between 1.5 and 5 seconds to load, with CPU utilization ranging from 30% to 100%. Others show the same material loading in about half a second with less than 5% CPU utilization, indicating that the GPU has taken over the job.
The demo showed promising early results for hardware outside of Microsoft Labs. In addition, they showed a huge shift in 2020 testing, showing that recent games have not taken full advantage of the bandwidth benefits of NVMs over SATA drives.
At GDC in March, Square Enix claimed that DirectStorage allowed Forspoken to load new scenarios and environments in less than 2 seconds on NVMe SSDs, compared to a few seconds on SATA SSDs and nearly half a minute on HDDs. Microsoft has designed new APIs for Windows 11. Windows 10 systems will see only limited benefits due to its legacy storage stack.
