Applicable Countries

                    World-Wide

                    Service Hints & Tips


                    Symptom:
                    ValuePoint Performance series system upgraded with
                    IntelDX4 Overdrive chip will not run at 50/100 MHz.

                    Problem Isolation Aids:
                    None.

                    Fix:
                    The ValuePoint Performance system board can be jumpered
                    to run at 25, 33, 40 or 50 MHz. The Intel DX4 processor (the
                    standard 3.3 volt chip) can run at 2X, 2.5X or 3X the planar
                    speed. Thus for optimum performance the VP-p 100DX4/p
                    systems shipped by IBM run the planar at 50MHz and
                    double-clock the CPU at 100MHz.

                    However, the IntelDX4 Overdrive (retail upgrade) chip can
                    only triple-clock. If an SX, DX or DX2 system is upgraded
                    using the DX4 Overdrive the planar must be jumpered to
                    33MHz (ie 33/100 MHz operation). You cannot run at
                    50/100MHz with the Overdrive DX4. Do not attempt
                    40/120MHz either - the system may appear to work OK but
                    the CPU will overheat and/or produce incorrect results.

                    Note:
                    F1 Setup may not report the correct processor type or
                    speed if a DX4 Overdrive is fitted, however the DOS
                    command QCONFIG will.