Intel has acknowledged that its Orion chip set contains an error that may cause data corruption or even system failure when servers using the chip set implement certain memory configurations.
The company says that systems with the 82450KX/GX PCIset are vulnerable when combining single- or double-sided SIMMs or Dual In-Line Memory Modules (DIMMs) with different memory sizes.
The Pentium Pro chip set is used primarily on systems designed for symmetric multiprocessing (SMP).
Company officials say problems could arise when 8Mb or 32Mb DIMMs are mixed with modules that contain other memory amounts or when there are no DRAM modules in the first row (row 0) of the memory subsystem.
Intel also says users should exercise caution when using 4Mb or 16Mb SIMMs in conjunction with other module sizes.
The error does not affect systems that support only one row of memory.
Intel officials say they have alerted OEMs to the problem so that methods of handling it could be included in their product documentation. They also say server vendors have so far fielded few, if any, reports of the error.
"We were able to implement work-arounds [for the error] at the board level, and we've made it very clear in the documentation that we require factory configurations with no mixing of memory sizes," says David Sorenson, prod-uct manager for advanced server systems for Advanced Logic Research.
Intel has announced several recommendations that will help users avoid the problem before it occurs: Always populate row 0 with DRAM modules in systems that contain multiple memory rows and use same-size DRAM modules whenever possible.
Intel has also told OEMs that when writing a BIOS for 82450KX- or GX-based systems, they should detect and flag in the product documentation potentially problematic memory configurations.
The importance of following the documentation cannot be overemphasised, vendors say.
"Theoretically, every Pentium Pro [SMP] system on the market could develop this error if users don't follow the documentation," says Kevin Roberts, product manager for high-performance workstations at ALR.
Analysts say users can also avoid the problem by using parity memory, which automatically sends out a warning message whenever a configuration error is detected.
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