NEC Direction SP B-Series, Руководство пользователя

Страница: 214 / 222

26 Glossary
WRAM
Windows RAM. A type of RAM that supports two ports. This
enables a video adapter to fetch the contents of memory for
display at the same time that new bytes are being pumped into
memory. This results in much faster display than is possible
with conventional single-port RAM. WRAM is similar to
VRAM, but achieves even faster performance at less cost
because it supports addressing of large blocks (windows) of
video memory. See VRAM and SGRAM.
write
To record or store information to a storage device.
write-back
Also called copy back. A cache strategy where write operations
to data stored in the internal microprocessor L1 cache aren’t
copied to system memory until absolutely necessary. In
contrast, a write-through cache performs all write operations in
parallel - data is written to system memory and the L1 cache
simultaneously. Write-back caching yields somewhat better
performance than write-through caching because it reduces the
number of write operations to main memory. See cache and
write-through.
write-through
Also write-thru. Write-through characterizes a cache strategy
where data is always written into system memory when data is
written by the CPU. See cache and write back.