Video Cards Question

[LegitGamer]

Hey all I have a quick question for you all and to anyone who knows I hope a get a answer. I recently downloaded the latest version of HWiNFO 64 and I ran it and noticed (if its true) my graphics bandwidth is only at 8gb/s it should be at 32GB/s, because it is PCI-E 3.0. So im  just woundering is this normal or should I do something. Heres a Sccreen capture:

Edited March 17, 2013 by LegitGamer

[WarWeeny]

gpu-z is your answer, download and start it, then you know for sure.

[IVIYTH0S]

I agree, get a second opinion, sometimes software misrepresents hardware values

[LegitGamer]

Thanks guys for the replies, but I already have GPU-Z and I don't think it says anything about the Gb/s interface.  I mean all it says in GPU-Z is (for the bus interface) PCI-E 3.0 x16 @ x16 3.0. For the Bandwidth 

to my video cards, it reads 144.2Gb/s, but this isn't what I'am after. I'm after the PCI-E 3.0 socket itself. I want to make sure its reading at 32GB/s like PCI-E 3.0 should.

[EuroFight]

PCIe 3.0 enables transfer speeds of up to 985MB/s per lane (compared to 500MB/s for PCIe 2.0).

 

PCIe x16 slots each run 16 lanes at the transfer speed, therefore we can find the total bandwidth for each x16 slot by calculating:

 

985 * 16 = 15760 MB/s Bandwidth for a x16 lane on PCIe 3.0

= 15.39 GB/s as a GB is 1024 MB

 

So we can say that a x16 lane can handle 16GB/s of data approximately. This still doesn't explain why you are getting only half of that (8GB/s of bandwidth).

 

PCIe 2.0 can only support a 500MB/s aggregate, however, and if we use the same calculation:

 

500 * 16 = 8000 MB/s Bandwidth for a x16 lane on PCIe 2.0

= 7.8125 GB/s

 

Which would suggest that the cards are running on PCIe 2.0 for some reason, or you have your cards plugged into the PCIe x16 slot that runs at x8. Some pictures/full specs would help me out here, I'm stuck!

 

P.S. I wouldn't worry either way, the GTX 660Ti would not max out the 8GB/s bandwidth anyway, not even a 7970 is bottlenecked significantly by PCIe 2.0.

[kyfire]

Your answer might be this (taken from Nvidia site GTX 660TI specs http://www.geforce.com/hardware/desktop-gpus/geforce-gtx-660ti/specifications

 

GeForce GTX 660 Ti supports PCI Express 3.0. The Intel X79/SNB-E PCI Express 2.0 platform is only currently supported up to 5GT/s (PCIE 2.0) bus speeds even though some motherboard manufacturers have enabled higher 8GT/s speeds.

[LegitGamer]

Ok so first, the HWiNFO 64 is reading my system the right way? Next, in my bios I have the PCI-e set to GEN3, so what your saying EuroFight, my 660ti's won't make my PCI-e lanes run at full speed? What about when I'm playing graphically intense game like Crysis 3 or Battlefield 3?
 
Thinks kyfire for the form for my cards.

Edited March 17, 2013 by LegitGamer

[EuroFight]

From what @kyfire said, it would seem as if your cards are running at PCIe 2.0 speeds instead of PCIe 3.0 speeds, hence this is why you are only getting an 8GB/s transfer speed.
 
The fact you have PCIe 3.0 enabled in the BIOS will not affect this;

 

Intel X79/SNB-E PCI Express 2.0 platform is only currently supported up to 5GT/s (PCIE 2.0) bus speeds even though some motherboard manufacturers have enabled higher 8GT/s speeds.

As the board is X79, the card will only run at PCIe 2.0 speeds (8GB/s, as shown earlier)

[LegitGamer]

As the board is X79, the card will only run at PCIe 2.0 speeds (8GB/s, as shown earlier)

But that is just wrong though, X79 boards where built to handle PCI-E 3.0 architecture to run at x16 (32GB/s) for at least the first 2 slots. I guess I'm lost here.

[EuroFight]

The board may be, but NVIDIA states that 'even though some motherboard manufacturers' have enabled the feature, it is not available on these cards.

 

NVIDIA limitation, not your motherboard. As previously stated, however, a 660 Ti will not max out the 8GB/s bandwidth.

[LegitGamer]

So what your saying is, now call me stupid, lol, a 690 will run at full 32GB bandwidth but a lower end card will run at 8GB/s tops? What about on full load in games and GPU stress tests?

[Waco]

So what your saying is, now call me stupid, lol, a 690 will run at full 32GB bandwidth but a lower end card will run at 8GB/s tops? What about on full load in games and GPU stress tests?

A 690 can't use more than a single slot can provide either...but no, running at 8 GB/s won't change your scores by any noticeable amount in any benchmark.