dma on DDR ram main memory? - High Speed Data Logging Sought

haiticare2011 · 2014-04-28T09:56:10+00:00

Greetings, I was interested in how a rapid data-gathering computer could do ADC on various sensors and then store quantities of data to disk continuously. At first I thought dma, but then considered difficulty of programming - handshaking on bus, etc. Then I looked at Ram Disks, and came across gamers' use of DDR Ram in large amounts to substitute for a disk. One such is "dimmdrive" which boasts transfer rates of 8000 mb/s. The advantage of a DDR main memory drive like this: It's a fast bus near the cpu, and it's very easy to program with file i/o. DDR ram is about $10 a gb, retail. The question I have is: Is it possible to offload the DDR RAM main memory via a paging scheme plus dma transfer to a disk? In other words, can the cpu continue to gather data with minimal interruption? Someone may know of this commercially available at low cost - hooray if true. Other wise, any comments sought about the feasibility of dma on the DDR ram. Note: I believe it's acceptable to fill an area of ram, and then move to another area under cpu control, as the dma process stores the first area on disk. One way to think about this is that the cpu + DDR ram is a unit with good, high-speed software access. So that unit should probably be kept intact. TIA, j