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Old March 11th 04, 07:41 AM
CBFalconer
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CJT wrote:
CBFalconer wrote:
Colin Painter wrote:

If I can add a bit to JT's reply...

If you are overclocking your memory you risk getting more errors
than the guys who built the memory planned on. If the memory is
not ECC memory then you may get more single bit errors which will
cause your machine to stop when they occur. ECC memory can
correct single bit errors but non-ECC memory can only detect them
and when that happens windows will blue screen. Most home PCs
have non-ECC memory because it's cheaper.


Correction here - non ECC memory won't even detect any errors, it
will just use the wrong value. Sometimes that MAY cause the OS to
crash. Unfortunately the rest of the thread is lost due to
top-posting.

You seem to have confused ECC and parity. ECC means error checking
and correcting, which involves more redundancy than simple single bit
parity error checking.


Nothing uses parity checking today - that requires writing
individual 9 bit bytes. Expanded to a 64 bit wide word (for the
various Pentia etc.) the parity or ECC bits both fit in an extra 8
bits, i.e. a 72 bit wide word. If todays systems have no ECC they
have no checking of any form. ECC is actually no harder to handle
on wide words.

Memory configurations that can use parity can use ECC, the reverse
is not true.

Exception - some embedded systems with smaller memory paths may
use parity.

--
Chuck F ) )
Available for consulting/temporary embedded and systems.
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