The adoption of PCI Express 4.0 by AMD and its motherboard partners in late 2019 paved the way for incredibly fast solid state drives with sequential read/write speeds of approximately 5,000 MB/s at full utilization. PCIe 4.0 bus is already saturated, but XPG is showing off a new prototype model that can read data at an even more furious pace: speeds in excess of 7,000 MB/s.

This is a difference of 2,000 MB/s. To put this in perspective, some of the best SSDs for gaming are still SATA-based models, with read/write speeds of around 550 MB/s (such as Samsung's 860 Evo and Crucial's MX500). And in the NVMe realm, our top pick, Crucial's P1 1TB SSD, offers up to 2,000 MB/sec read and 1,700 MB/sec write.

In other words, the difference in read speed between XPG's prototype model and the scattered PCIe 4.0 SSDs corresponds to the maximum speed of Crucial's P1.

One of the special source components that makes these speeds possible is the PCIe 4.0 bus, which provides twice the bandwidth of PCIe 3.0. For consumers, AMD's X570 chipset and the latest generation of Ryzen processors support PCIe 4.0.

The controller is another key element, and if you like technical details, that's where it gets interesting: the SSD controller is a dedicated chip that controls the operation of the SSD and is also the part that determines how fast data is read and written. All PCIe 4.0 SSDs on the market today use Phison's PS5016-E16 controller. The maximum speed of this controller, like few PCIe 4.0 SSDs, is about 5,000 MB/sec.

Last summer, Phison said it was working on a new controller that would enable speeds of 6.5 GB/s in 2020 and would be available in the first quarter of this year. As far as I know, those plans are still intact.

But XPG is not waiting. At least two of the company's three prototype SSDs-Sage, Indigo, and Pearl-use non-Phison controllers; the Indigo SSD (pictured above) uses a Silicon Motion SM2264 controller. Here are the specs for that model:

Details on XPG's Pearl model are not available, but the Sage model appears to be at the top of the stack with slightly better performance than the Indigo drive.

The Sage SSD uses the new Innogrit Rainier IG5236 controller, one of the first drives to use it; our friends at Anandtech have covered the technical details about this controller, so if you're curious, check there! Please note that the IG5236 delivers much faster performance than Phison's E16 controller. Here are the Sage specs:

These are all preliminary indications; XPG testing has shown even faster read speeds, possibly eventually exceeding 7,000 MB/s. The results achieved by the demo drive at CES in the CrystalDisk benchmark are as follows: [19 According to our friends at Toms Hardware, XPG expects the write speed to reach 6,000MB/s by the time Sage reaches final production. XPG has also indicated that when these drives hit retail store shelves, they will be fitted with heatspreaders, rather than the bare-bones design shown above. [Moving from SATA-based SSDs to XPG Sage will not make a noticeable difference in gaming loads. But there are still several reasons to be concerned: one is that the speed will come in handy when moving large files or bundles of them, especially for large backup tasks. And another is that as companies push the envelope in this way, the price of slower, older generation models may come down.

On the latter point, there are market indicators that SSD prices could rise this year as the cost of NAND flash memory chips increases. Therefore, moves to counter the projected price increases are certainly commendable.

XPG did not state the price of the next model, only that it will be available later this year.