About a year ago, I tried to use the Gigabyte GC-RAMDISK/iRAM SATA RAMDISK and ran into horrible problems. I was looking for a non-volatile storage device that I could use for ZFS logs, so
fsync() and friends could complete in a millisecond or two, but it was pretty clear that the iRAM just wasn’t going to work for me. Unfortunately, there really weren’t any alternatives on the market at the time; a few manufacturers made PCI NVRAM cards, but they were all OEM-only and I couldn’t find anyone to sell me one. What I really wanted was a device with around 4 GB of RAM, a CF slot, a SATA port, and a battery. It’d act like a RAM-backed SATA device, with fast I/O speeds, but when the power died it’d use the battery to copy everything from RAM onto the compact flash card. Then at bootup it’d copy it all back.
Amazingly enough, ACARD managed to sneak two of these onto their website in July. The ANS-9010B lists for $249 and has 6 DDR2 slots and 1 SATA port, while the ANS-9010 lists for $399 and has 8 DDR2 slots and 2 SATA ports. Neither one is widely available yet, but it sounds like they’re starting to trickle into the US.
I’d like to see a few benchmarks when they’re actually available. In theory a RAM-based NVRAM device should have substantially higher write speeds than a flash SSD, but it’s been screwed up before, and flash SSDs are widely available and constantly dropping in price.