Dell™ PowerEdge™ R710 Technical Guidebook35b. Pci express RisersThe two PowerEdge R710 PCI Express risers provide up to four expansion slots and one internal slotas follows:• Two x8 and two x4 PCI Express Gen2 slots, connected to the IOH• One x4 PCI Express Gen1 slot for internal storage, connected to the IOH• Support for three full-height 9.5" long PCI Express cards and one full-height bracket, low-profilePCB PCI Express card• Support for field upgrading one slot (on the center riser) to a full-length 12.2" PCI Express card• System supports 25W maximum power for the first two cards and 15W for the third andfourth cards• The lower power support on the third and fourth cards is due to system thermal limitations• An optional x16 riser to accommodate interface cards for external GPU boxes that supports amaximum power of 25W. Use of this riser reduces the number of PCI Express slots from fourto threec. additional Riser Restrictions• The riser connectors on the planar do not support plugging in a standard PCI Express card. Donot attempt this for troubleshooting.• Two PowerEdge R710 risers must be installed or the system will not power up.D. x16 express card specificationsThe PowerEdge R710 supports x16 cards that meet the following requirements:• Standard height (4.376")• Maximum length of 9.5" (Half-length cards are 6.6"; Full-length cards are 12.283")• x16 cards can only plug into the optional PowerEdge R710 x16 left riser• Support for full bandwidth of x16 Gen2 link• No support for hot-plug or hot-removal• Maximum power of 25W• The PowerEdge R710 provides +12V, +3.3V, and +3.3Vaux in accordance with Power Supply RailRequirements (Table 4-1 of PCIe Card Electromechanical Spec, Rev 2.0)• The PowerEdge R710 x16 slot is not compliant with the PCI Express x16 Graphics150W-ATX Specification• x16 cards must be compliant with the PCI Express Card Electromechanical Specification Rev 2.0• x16 cards must only occupy the space of one slot. Cards that occupy the space of two slots arenot supported• The x16 card is limited to 25W initial start-up power until it is configured as a high-powerdevice. If no value is set for the Slot Power Limit, the card is limited to 25W. The card must theneither scale down to 25W or disable operation per PCI Express Base Spec Rev 2.0• The x16 card must be able to support a maximum operating temperature of 55°C as defined inthe Dell PCI Environmental Spec and the PCI Express Card Electromechanical Spec. ThePowerEdge R710 provides a minimum transverse air velocity of 100 LFM (linear feet per minute)to the x16 card.e. boot OrderPCIe scan order (from the BIOS HW spec v1.0)IOH port 1,2 (PCI Express Gen1 x4) – Broadcom BCM5709C Gigabit Embedded NIC #1IOH port 3 (PCI Express Gen1 x4) – Broadcom BCM5709C Gigabit Embedded NIC #2IOH port 4 in Bluefish or ICH9 port1-4 in Thidwick (PCI Express Gen1 x4) – Integrated PERC6i or SAS6ion the Riser 1IOH port 5 (PCI Express Gen2 x4) – Slot 2 on Riser 1IOH port 6 (PCI Express Gen2 x4) – Slot 1 on Riser 1IOH port 7/8 (PCI Express Gen2 x8) – Slot 3 on Riser 2IOH port 9/10 (PCI Express Gen2 x8) – Slot 4 on Riser 2For PCI-e X16 optional left riser, IOH port 7,8,9,10 are combined into one x16 PCI-e slot.