[CentOS] network interface cards with gig support

anyone know how to force network cards talk at gig speeds when all it
wants to do is establish a connection at 100mbits

root at host1 [/backup/cpbackup/daily]# mii-tool
eth0: negotiated 100baseTx-FD, link ok
eth1: negotiated 100baseTx-FD flow-control, link ok


01:00.0 Ethernet controller: Broadcom Corporation NetXtreme BCM5721
Gigabit Ethernet PCI Express (rev 11)
        Subsystem: Broadcom Corporation NetXtreme BCM5721 Gigabit
Ethernet PCI Express
        Flags: bus master, fast devsel, latency 0, IRQ 169
        Memory at dd100000 (64-bit, non-prefetchable) [size=64K]
        Capabilities: [48] Power Management version 2
        Capabilities: [50] Vital Product Data
        Capabilities: [58] Message Signalled Interrupts: 64bit+
Queue=0/3 Enable-
        Capabilities: [d0] Express Endpoint IRQ 0
        Capabilities: [100] Advanced Error Reporting
        Capabilities: [13c] Virtual Channel

02:00.0 Ethernet controller: Broadcom Corporation NetXtreme BCM5721
Gigabit Ethernet PCI Express (rev 11)
        Subsystem: Broadcom Corporation NetXtreme BCM5721 Gigabit
Ethernet PCI Express
        Flags: bus master, fast devsel, latency 0, IRQ 169
        Memory at dd200000 (64-bit, non-prefetchable) [size=64K]
        Capabilities: [48] Power Management version 2
        Capabilities: [50] Vital Product Data
        Capabilities: [58] Message Signalled Interrupts: 64bit+
Queue=0/3 Enable-
        Capabilities: [d0] Express Endpoint IRQ 0
        Capabilities: [100] Advanced Error Reporting
        Capabilities: [13c] Virtual Channel