Re: Disk to disk copying with overclocked memory

Tech-Archive recommends: Repair Windows Errors & Optimize Windows Performance

From: CBFalconer (cbfalconer_at_yahoo.com)
Date: 03/11/04 

Date: Thu, 11 Mar 2004 06:41:01 GMT

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 (cbfalconer@yahoo.com) (cbfalconer@worldnet.att.net)
   Available for consulting/temporary embedded and systems.
   <http://cbfalconer.home.att.net>  USE worldnet address!

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