The Intel DC P3700 is pretty good and can be had in the PCIe card version for reasonable prices. If you can use the U.2 form factor, though, nothing comes close to the Optane 900p...it's only about 2x the cost of the P3700, and gives you enough extra performance to be worth it. If you have to have a PCIe card, though, you can't really find a 900p for less than 3x the cost of the P3700, and that might not be worth it.