When Memory Serves You: Using ramfs and tmpfs
Feb 01, 2010, 15:33 (1 Talkback[s])
(Other stories by Ken Hess)
[ Thanks to An Anonymous Reader for
this link. ]
"If your read/write performance isn't keeping up with
your needs, the least expensive and least time-consuming fix is to
place those heavily used files into RAM. Reading and writing to RAM
is significantly faster than when using disk-based filesystems.
Disk I/O-sensitive data transfers, like those involving databases,
reap extreme benefits from moving to RAM-based filesystems.
"Why RAM? RAM is fast. It operates in nanosecond-level access
times whereas the fastest disk operates in millisecond-level access
times. RAM doesn't spin. Mechanical drives spin, which means their
read/write and seek speeds are significantly slower than their
RAM-based equivalents. DDR3 RAM, for example, moves data in and out
at solder-melting peak rates exceeding 10GB/s. Even Hitachi's
hottest 15,000 RPM UltraStar disk, transfers data at a sluggish
119MB/s to 198MB/s sustained and 600MB/s max. RAM has longer MTBF
(Mean Time Between Failures). Since RAM isn't mechanical, it
doesn't enjoy the high failure rates of spinning disks, therefore
giving it a life expectancy well beyond that of a typical disk
drive."
Complete
Story
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