Currently I have been running OCZ Vertex 4 (256GB) with no issue so far since two years.
I had also Samsung 830 Pro and Crucial MX100 as an cache drive without any issue.
Last year I tried OCZ Vector 180 and had some issue with the file transfers and I/O operations as the system hangs for few seconds. I read somewhere that this is the issue with controller on that particular ssd.
I'm using Crucial 4 x 4GB 240-Pin DDR3 SDRAM ECC Unbuffered DDR3 1333 (PC3 10600) Server Memory Model CT51272BA1339 on my X9SCM-F-O with Xeon E1230 (ESXi 5 and unRAID + some other guests).
http://www.newegg.com/Product/Product.aspx?Item=N82E16820148382
I have started with 4GB stick adding 4GB every other week. Now I have 16GB. This MB works with 4GB, 8GB, 12GB without any issue for me.