Meet Micron's P320h PCI Express-Based SSD
A number of storage vendors have jumped into the PCI Express-based SSD market during the past 18 months. With a few exceptions (notably, Fusion-io), the formula is fairly simple. Take a few SATA-based controllers, mix in a RAID controller, some RAM, set the blender to emulsify, and in a few minutes you have a storage device unencumbered by the 6 Gb/s SATA interface.
Alright, so it's not quite that simple. But those are the basic building blocks we're seeing from most vendors. Micron eschews that approach by baking up something completely different.
Meet the company's P320h half-height, half-length PCI Express-based SSD. The P320h is available in 350 and 700 GB capacities, selling for $3,495 and $6,995, respectively. That's expensive, no doubt. But for $10/GB you get very impressive performance specifications.
You should be aware that Micron sells the RealSSD P320h in one other format (aside from the half-height, half-length design we're reviewing today). Its 2.5" PCI Express RealSSD P320h is available in 175 and 350 GB capacities, but is limited to 415,000 4 KB random read IOPS and 1.75 GB/s in sequential reads. Though those numbers are still impressive, the form factor requires a server equipped with the right interface to support it.
| Micron P320H | ||
|---|---|---|
| User Capacity | 350 GB | 700 GB |
| Interface | PCI Express 2.0 x8, Half-Height, Half-Length | |
| Sequential Read | 3.2 GB/s | |
| Sequential Write | 1.9 GB/s | |
| 4 KB Random Read | 785,000 IOPS | |
| 4 KB Random Write | 205,000 IOPS | |
| Power Consumption (Active) | 25 W | |
| Power Consumption (Idle) | 10 W | |
| Write Endurance | 25 PB | 50 PB |
With specified read performance up to 3.2 GB/s and as many as 785,000 4 KB random write IOPS, Micron is basically saturating a second-gen PCI Express x8 link with the HHHL version of its P320h. The use of single-level cell NAND allows for 50 PB of write endurance on the 700 GB variant. At a high level, those are all impressive numbers. But lets take a deeper look to see how Micron achieves such ambitious specs.