Enabling pcie power override – HP MSR Encryption Accelerators User Manual
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Maintenance 36
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fio-update-iodrive
For more information, see "Utilities reference (on page
)."
Enabling PCIe power override
For PCIe IO Accelerators, if you have installed any dual IO Accelerator devices, such as the HP ioDrive2
Duo, then the device might require additional power than the minimum 25 W provided by PCIe Gen2 slots
to properly function. Even if additional power is not required for your device, all dual IO Accelerator devices
that receive additional power might benefit with improved performance.
HP ioDrive2 Duo devices must have additional power to properly function. For more information on which
devices require additional power, see the HP PCIe IO Accelerator for ProLiant Servers Installation Guide.
Additional power can be provided in two ways:
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External power cable—This cable ships with all dual ioMemory devices. For information on installing
this cable, see the HP PCIe IO Accelerator for ProLiant Servers Installation Guide.
NOTE:
When a power cable is used, all of the power is drawn from the cable and no power is
drawn from the PCIe slot.
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Enabling full slot power draw—Some PCIe slots provide additional power (often up to 75 W of power).
If your PCIe slot is rated to provide at least 55 W, then you can allow the device to draw full power from
the PCIe slot by setting a VSL module parameter. For more information on enabling this override
parameter, see "Enabling the override parameter (on page
)."
CAUTION:
If the PCIe slot is not capable of providing the needed amount of power, then
enabling full power draw from the PCIe slot might result in malfunction or even damage to server
hardware. The user is responsible for any damage to equipment due to improper use of the
override parameter. HP expressly disclaims any liability for damage arising from improper use of
the override parameter. To confirm the power limits and capabilities of each slot, as well as the
entire system, contact the server manufacturer. For information about using the override
parameter, contact HP Customer Support.
NOTE:
The override parameter overrides the setting that prevents devices from drawing more
than 25 W from the PCIe slot. The parameter is enabled by device using the device serial
numbers. Once the setting is overridden, each device might draw up to the full 55 W needed for
peak performance.
Before you enable the override parameter, ensure that each PCIe slot is rated to provide enough power
for all slots, devices, and server accessories. To determine the power slot limits, consult the server
documentation, BIOS interface, setup utility, or use the fio-pci-check command.
Important considerations
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If you are installing more than one dual IO Accelerator device and enabling the override parameter for
each device, be sure the motherboard is rated to provide 55W power to each slot used. For example,
some motherboards safely provide up to 75W to any one slot, but run into power constraints when
multiple slots are used to provide that much power. Installing multiple devices in this situation might
result in server hardware damage. Consult with the manufacturer to determine the total PCIe slot power
available.
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The override parameter persists in the system and enables full power draw on an enabled device even
if the device is removed and then placed in a different slot within the same system. If the device is placed
- AXL300 Accelerator SSL PCI Card Thunderbolt-2 PCIe 1-port IO Card Storage C-series Switch Accelerators Fusion ioFX 410GB PCIe Accelerator Thunderbolt 2-Port AiO Module B-series Switch Accelerators IO Accelerator for BladeSystem c-Class HPAtalla AXL600L SSL Accelerator Card PCIe IO Accelerators for ProLiant Servers