Phison demos Apex PCIe 5.0 RAID matrix breaking 140 GB/s SSD transfer speeds

PCIe 5.0 is the fastest expansion bus standard available for mainstream SSDs at present, which enables transfer speeds in excess of 14 GB/s. Every next PCIe generation essentially doubles the peak theoretical speeds of the previous one, so the upcoming PCIe 6.0 standard is expected to enable transfer speeds reaching close to 28 GB/s on 4 lanes, while PCIe 7.0 would allow for speeds hitting almost 56 GB/s on 4 lanes. However, one does not actually need to wait around for future PCIe generations in order to benefit from increased speeds well above what the theoretical maximum offered by PCIe 5.0. At Computex this year, Phison collaborated with Apex Storage to demonstrate a solution that connects up to 32 PCIe 5.0 SSDs in RAID 0 to offer speeds equivalent to PCIe 7.0 X8 and beyond.

For the demonstration running at its Computex booth, Phison set up an AMD-powered system powered by an AMD Ryzen Threadripper Pro 7985WX on an Asus Pro WS WRX90E-SAGE SE motherboard that features no less than 7x PCIe 5.0 slots. Phison only needed three of these slots for a RAID matrix with 32 SSDs spread over 3 Apex cards. 

Even though only two cards could have been used for a 32 SSD matrix, it looks like spreading the SSDs over 3 cards helped boost the transfer speeds even higher, as the sequential speeds reached 113.6 GB/s and the sequential write speeds were a bit lower at 104.6 GB/s in CrystalDiskMark 8.0.6. This version of the popular SSD benchmark also includes a Mix test that combines 70% of the read speeds with 30% of the write speeds where the Phison matrix reached an impressive 146 GB/s transfer rate.

The 32 SSD matrix includes Phison’s new PS5028-E28 Gen5 individual units. This model is produced on TSMC’s N6 fabrication nodes and is rated for a maximum read speed of 14.8 GB/s, whereas write speeds go up to 14 GB/s, with random transfers hitting up to 3,000K IOPS.

Phison mentioned that the current Windows 11 kernel used for the tests is limiting the speeds, so there is potential for even higher transfer rates with improved OS code. Speaking of limits, the PM584 microchip switch with 84 lanes powering each Apex card is currently limited to 128 TB per matrix, meaning that the configuration could include 32 X 4 TB SSDs on two cards or 16 X 8 TB SSDs on one card.