Retail SSDs supporting the latest PCIe Gen 5 interface will finally be detailed at CES 2023 We've already seen Phison show off its latest E26 PCIe 5.0 controller chip (opens in new tab) in an engineering demo drive. But now we are about to get the actual retail drive itself.

To summarize briefly, PCIe Gen 5 doubles the peak bandwidth of Gen 4. This means a maximum throughput of 16 GB/s versus 8 GB/s. In practice, the actual maximum bandwidth achievable is less than that due to various protocol overheads.

The best 4th generation drive is about 7.3 GB/sec. Thus, an area of 14.5GB/sec to 15GB/sec should ultimately be achievable with a 5th generation drive. But perhaps not with the first Gen 5 SSDs. But the first Gen 5 SSDs will be a bit slower, albeit still ridiculously fast.

Let's take a look at the XPG PCIe Gen5 SSD. According to Adata, it will be 14GB/s read and 12GB/s write. Interestingly, it uses Silicon Motion's SM2508, perhaps another big player when it comes to off-the-shelf controller chips for Gen 5 drives, rather than the reputed Phison E26 controller chip.

Notably, the Silicon Motion SM2508 is good for both 2 million read and write IOPS. This is slightly better than the Phison E26, which is rated at 1.5 million reads and the same 2 million writes.

While an SSD with a peak throughput of 14GB/s sounds quite appealing, there is no doubt that it is the 4K random accesses, determined by IOPS performance, that will most determine how snappy the drive will run a PC.

IOPS performance is also the area where NAND-based SSDs have seen the least improvement in recent years. Basically, with the exception of Intel's now-defunct Optane drive, all SSDs have had much better IOPS performance.

Nevertheless, given the rumors on the street that sufficiently fast NAND is available and the generally slower launch schedule for 5th generation drives, the huge peak throughput numbers of 14B/sec and 12GB/sec that Adata's drives use to achieve it is curious what the flash memory chips are.

In this regard, MSI is showing the Spatium M570 and M570 Pro drives along with the Adata drives. Both drives feature the Phison E26 controller; the non-Pro drives log 10 GB/s in both read and write, with the Pro model improving to 12 GB/s in read.

This 12GB figure is due to Micron's latest 232-layer NAND flash. Therefore, it is unclear how Adata achieves 14 GB/sec. Also, Adata has not yet discussed a release date for the drive, so this comparison is somewhat academic.

MSI has not published IOPS performance for the new drive, but early benchmarks run at the show by our sister site Tom's Hardware (opens in new tab) show the Pro drive at just 76 MB/sec for 4K QD1 read and 252 MB/sec for write numbers that were not terribly impressive, putting it behind even the best Gen 4 drives.

Of course, MSI would argue that this drive is not the final retail unit. However, we recorded over 12 GB/s on sequential reads and just under 12 GB/s on sequential writes. In other words, there is a clear speedup in performance; 4K does not bode well.

In any case, once the first drives are released, PCIe Gen 5 technology is sure to develop rapidly. While the actual release date and price of these drives is not yet known, that day seems to be approaching. Expectations are high.