pci-e 3.0 x16 unning at pci-e 2.0 x8?

goingincircles

Distinguished
May 22, 2014
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hi first time poster but a regular reader of the site 🙂
im wondering if someone can tell why in gpu-z it says my gpu is running pci-e 3.0 x8 @ x8 1.1 idle and when in use its pci-e 3.0 x8 @ x8 2.0 .
my motherboard is pci-e 3.0 and also my graphics card so shouldnt it be running at 3.0 x16?
ive taken screen shots of gpu-z so you can see what i see.
any ifomation would be welcomed 🙂

first picture is idle 2nd picture is with render test

gtc.png


dwn.png



my system....

amd x4 750k cpu
gigabyte r7 240 oc 2gb ddr3 pci-e 3.0 x16
4gb corsair xms3 1600mhz
gigabyte GA-F2A88XM-DS2 (rev. 3.0) motherboard pci-e 3.0 x16
corsair vs650 650w
 
Solution


That can't be.
Unless, you have a PCI-E USB3 card attached with a fast hard drive that's transferring data at the same time, but it goes only upto around 100MB/s realistically for a hard drive, and for a SSD, it's max. 5Gbps(625MB/s).
Even assuming you have a PCI-E USB3 card, it's only upto x4, and doesn't take enough bandwidth to slow down your graphics card considerably. A PCI-E 3.0 x8 slot will have around 8 GB/s of bandwidth(64 Gbps; very high compared to even full USB3).
Your card seems to be the one of the low-profile versions of the R7...


FM2+ processor is needed for pcie 3.0

Having said that, the slot should be running at 2.0 x16 with that processor.


Make sure you have the mobo drivers/bios up to date.

 


ive tried auto, gen 1 and 2 and still the same!!
ive read online last night it could be my cpu? Its not compatible with pci-3.0!! Or something lol. Which confused me coz if it only run at pci-e 2.0 then why am i only running 2.0x 8 shouldnt it be 2.0 x16?
 


 
ive just also noticed if you look on the pictures my gpu memory is 800mhz but the specs of the card insist its 1600mhz!! would the gpu need a bios update of somekind? ive updated the bios on the mobo but i havent a clue about gpu`s
 


hi cst1992 thanks for clearing that bit up! would you have any idea what my other problem is?
ive just read it could be my usb 3 ports taking lane bandwidth making my pci-e slot run x8?
 




It should be 900mhz core, 900mhz memory I think... Are you using a program like afterburner?
 


im using gpu-z and it shows gpu clock 900mhz and memory 800mhz


 


That can't be.
Unless, you have a PCI-E USB3 card attached with a fast hard drive that's transferring data at the same time, but it goes only upto around 100MB/s realistically for a hard drive, and for a SSD, it's max. 5Gbps(625MB/s).
Even assuming you have a PCI-E USB3 card, it's only upto x4, and doesn't take enough bandwidth to slow down your graphics card considerably. A PCI-E 3.0 x8 slot will have around 8 GB/s of bandwidth(64 Gbps; very high compared to even full USB3).
Your card seems to be the one of the low-profile versions of the R7 240 or 250, which are PCI-E 3.0 x8 cards at 800 MHz memory clock.
Your card is running normally. Nothing to worry about.
 
Solution




its completley baffled me lol, im not to worried really i was more curious than anything, i did a windows rating test thing and the cpu scored 7.3 and gpu 6.8.
im not a gamer its my personal comp for watching tv and movies so im happy with how its performing so far.
its not a massive card but its not the lp version rev 2.0