Parity Errors Often Not Due to "Usual" Causes (98419)






This article was previously published under Q98419

SUMMARY

Parity errors (for example, OS/2 = Trap 0002, Windows NT = F002) are often blamed on bad machine memory when they actually are caused by other factors.

Many machines showing parity errors don't have bad (as in damaged) memory chips in them; instead, they have memory that is being overspeeded, and if you replace the suspected chips with chips of the same memory type, the problem is not solved. Overspeeded memory becomes unreliable if it is not rated to handle the CPU speed that the CPU and system clock are trying to run.

Parity errors also can result from a number of motherboard designs with bus controllers that are defective as shipped from the factory. This problem is generally limited to the "cheap off-brand clone" motherboards. That's one reason they are so cheap: they don't work properly.

Loose-fitting SIMMS can also cause parity errors.

Before setting off on complicated and unnecessary substitutions or repairs, make sure you find the true cause of a parity error.

Modification Type: Major Last Reviewed: 7/30/2001
Keywords: KB98419