Re: memtest86, built into kernel
Matthew J Brown (mjb@sophos.com)
Mon, 22 Apr 1996 17:29:56 +0100
Matti E. Aarnio writes:
>> No mainframes ran with ECC memory boards, so hardware faults got logged.
>> PC's _had_ parity to show you errors in RAM. Now they don't bother (I guess
>> because the people who make the PC's make so much bad memory they dont want
>> you to find out).
>
> http://www-cs.intel.com/oem_developer/chip_pci.htm
>
> Pick "General" from that (the URL is VERY long..), and
> go see about "Evaluating the Need for Parity in Desktop PCs"
Basically they say there that with modern SIMMs the MTBF for a soft
error (ie. alpha particle corruption) is between 12-30 years of
continual system use.
Given that it happens so rarely, that parity is only 50% likely to
catch the error anyway, and that parity requires an extra 12.5% DRAM,
it doesn't seem worth it to me. ECC is more useful, since it will
correct single-bit errors rather than just hanging.
-Matt