what bootcamped windows shows about link speed/type ?
GPU-Z says (exactly):
Bus Interface

CI-E x16 (@16)
Doesn't say 2.0... not sure if it's supposed to.
EDIT:
Looks like same in windows according to PC wizard 2009:
Either this:
Device : ATI Technologies Inc
Version : 2.0
Port : 4
Link Width : x16 (max. x16)
Link Speed : 2.5 GB/s
Complete info:
PCI-Express Information :
Number of connectors : 5
PCI-Express Base : 0xE0000000
Bus PCI-Express :
Device : 5400B Chipset Memory Controller Hub
Version : 2.0
Port : 0
Physical Slot : Integrated
Link Width : x4 (max. x4)
Link Speed : 2.5 GB/s
Bus PCI-Express :
Device : 5400 Series Chipset PCIe Port 1
Version : 2.0
Port : 4
Physical Slot : #0
Slot Populated : Yes
Link Width : x16 (max. x16)
Link Speed : 2.5 GB/s
Bus PCI-Express :
Device : 5400 Series Chipset PCIe Port 5
Version : 2.0
Port : 8
Physical Slot : #0
Slot Populated : No
Link Width : max. x16
Link Speed : 2.5 GB/s
Bus PCI-Express :
Device : 5400 Series Chipset PCIe Port 9
Version : 2.0
Port : 12
Physical Slot : Integrated
Link Width : x4 (max. x4)
Link Speed : 2.5 GB/s
Bus PCI-Express :
Device : 631xESB/632xESB/3100 PCIe Root Port 1
Version : 1.0
Port : 1
Physical Slot : #0
Slot Populated : No
Link Width : max. x1
Link Speed : 2.5 GB/s
Bus PCI-Express :
Device : 631xESB/632xESB/3100 PCIe Root Port 2
Version : 1.0
Port : 2
Physical Slot : #0
Slot Populated : No
Link Width : max. x1
Link Speed : 2.5 GB/s
Bus PCI-Express :
Device : 631xESB/632xESB/3100 PCIe Root Port 3
Version : 1.0
Port : 3
Physical Slot : #0
Slot Populated : Yes
Link Width : x1 (max. x1)
Link Speed : 2.5 GB/s
Bus PCI-Express :
Device : 631xESB/632xESB/3100 PCIe Root Port 4
Version : 1.0
Port : 4
Physical Slot : #0
Slot Populated : No
Link Width : max. x1
Link Speed : 2.5 GB/s
Bus PCI-Express :
Device : 631xESB/632xESB PCIe Upstream Port
Version : 1.0
Port : 0
Link Width : x4 (max. x8)
Link Speed : 2.5 GB/s
Bus PCI-Express :
Device : 631xESB/632xESB PCIe to PCI-X Bridge
Version : 1.0
Port : 0
Link Width : x4 (max. x8)
Link Speed : 2.5 GB/s
Bus PCI-Express :
Device : 631xESB/632xESB PCIe Downstream Port E1
Version : 1.0
Port : 0
Physical Slot : Integrated
Link Width : max. x4
Link Speed : 2.5 GB/s
Bus PCI-Express :
Device : 631xESB/632xESB PCIe Downstream Port E2
Version : 1.0
Port : 0
Physical Slot : Integrated
Link Width : max. x4
Link Speed : 2.5 GB/s
Bus PCI-Express :
Device : 631xESB/632xESB PCIe Downstream Port E3
Version : 1.0
Port : 0
Physical Slot : Integrated
Link Width : x4 (max. x4)
Link Speed : 2.5 GB/s
Bus PCI-Express :
Device : Texas Instruments (TI)
Version : 1.0
Port : 0
Link Width : x1 (max. x1)
Link Speed : 2.5 GB/s
Bus PCI-Express :
Device : ATI Technologies Inc
Version : 2.0
Port : 4
Link Width : x16 (max. x16)
Link Speed : 2.5 GB/s