Previously it was reported that the Viking Technology U.2 NVMe NVRAM drive was no longer available despite only a year after announcement, or at the least no ordinary humans could obtain it.
VT-PM8 & VT-PM16 Persistent Memory Drive - Viking Technology | Memory and Storage Solutions
RMS-200/8G PCI-e NVRAM Accelerator | eBay
Maybe not a good deal but interesting and rare hardware anyway.
On-Board Ultracapacitors (no remote ultracapacitor pack required)
Device Drivers NVMe Linux 2 2.6.38 and above
Write Throughput: 5 GB/s
Random 4K Write IOPS: 900K
Read Throughput: 5.2...