Technical > PC Hardware Discussion/Reviews > Using only the second PCIE x16 same speed ? for video card

Using only the second PCIE x16 same speed ? for video card

Always refer to the manufacturer's web site + user manual for details of this nature.

quote:

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2 x PCIe 3.0/2.0 x16 (x16 or dual x8) *3
1 x PCIe 2.0 x16 (x4 mode, black) *4

*3: PCIe 3.0 speed is supported by Intel 3rd generation Core processors.
*4: The PCIe x16_3 slot shares bandwidth with PCIe x1_2 slot. The default setting is x2 mode. Go to the BIOS setup to change the settings.

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reply to me
Also keep in mind you need an Ivy Bridge for PCIe 3.0 (3000 series CPU). Sandy Bridge (2000 series CPU) only supports PCIe 2.0.

reply to me
I recommend this board: »www.microcenter.com/product/3875···herboard

Out of the ones you have listed. As far as video cards go, if you have more than one card on the Sandy or Ivy bridge platform you will run at PCI-e x8 speeds for each card, that's just how the platform is architected. Otherwise usually the top slot is x16, but your motherboards manual will tell you more.

reply to koitsu
That was a great writeup BTW...

Thanks. I hope I got it all correct/right! I might be misunderstanding something about the "shared bandwidth" between the black and white/grey slot, but the rest should be correct for sure.
--
Making life hard for others since 1977.
I speak for myself and not my employer/affiliates of my employer.

Thanks for the explanation. Reading it without the pic the first time was a bit confusing

To sum it up, whether I use the first or second PCIe x16 slot, adding anything to the free slot will reduce the speed.

Is the first or dark blue slot immune to this effect? Can I put a PCIe x1 card in the second PCIe x16 (grey) without degrading the speed of the primary PCIe x16 slot (dark blue)?

reply to me
Basically, I need to be able to use 3 PCIe slots in x1 mode and I don't want my video card x16 performance affected.

Many boards cover up a PCIe x1 slot under the video card. (dual slot)

Please help me choose that card.

The board I suggested has 3 PCI-e x1 slots.

Your video card will run at x16 performance so long as you don't have another video card plugged into the other x16 slot. If you do, it will only run at x8 speeds, HOWEVER there is no noticeable difference at this point in time between x8 and x16 (3% difference or so) for graphics performance.

Beyond that, you can use an x1 card in the x4/x16 mechanical slot.

To expand on sk1939 's post mentioning the GA-Z77X-UD3H -- meaning I'm trying to make it more clear for you, me -- so please read slowly/thoroughly again --

First, see the zoomed in picture of the GA-Z77X-UD3H board and read the silkscreening labels on each of the slots (either above or along the edge of the slot). I'll describe each slot to you, from RIGHT TO LEFT:

PCIEX1_1 -- PCIe x1 slot, supporting up to x1 speed
PCIEX16  -- PCIe x16 slot, supporting up to x16 speed
PCIEX1_2 -- PCIe x1 slot, supporting up to x1 speed
PCIEX1_3 -- PCIe x1 slot, supporting up to x1 speed
PCIEX8   -- PCIe x16 slot, supporting up to x8 speed
PCI      -- standard PCI slot
PCIEX4   -- PCIe x16 slot, supporting up to x4 speed
 

To speak on the difference between the D3H and the UD3H, it boils down to having eSATA ports or not, that's it.

reply to koitsu
Thanks that clears up some things for me.

Between D3H and the UD3H I think UEFI BIOS is also a difference.

Edit:
Placing anything including PCEe x1 on PCIEX8 will affect PCIE16?

I went with the GA-Z77X-D3H rev 1.0 without knowing about that v1.1 is available.
This model has more SATA connections (which I may need). For $40 dollars less after rebate, I decided against UD3H.

Version 1 and 0 are basically the same except for a PCIe 3.0 issue.

GA-Z77X-D3H rev 1.0
1 x PCI Express x16 slot, running at x8 (PCIEX8)
* The PCIEX8 slot shares bandwidth with the PCIEX16 slot. When the PCIEX8 slot is populated, the PCIEX16 slot will operate at up to x8 mode.
(The PCIEX16 and PCIEX8 slots conform to PCI Express 3.0 standard.)
* PCIE Gen.3 is dependent on CPU and expansion card compatibility.
GA-Z77X-D3H rev 1.1
1 x PCI Express x16 slot, running at x8 (PCIEX8)
(The PCIEX16 and PCIEX8 slots conform to PCI Express 3.0 standard.)
* Whether PCI Express 3.0 is supported depends on CPU and graphics card compatibility.
* The PCIEX8 slot shares bandwidth with the PCIEX16 slot. When the PCIEX8 slot is populated, the PCIEX16 slot will operate at up to x8 mode.

Also 1 x 8-pin ATX 12V power connector for the UD3H
and 4 for D3H. (not sure if this will affect overclocking)

Comparison chart
»www.gigabyte.com/products/compar···153,4144

These would have been nice to have on my board
1 x power button
1 x reset button
1 x Clear CMOS button
1 x Voltage Measurement Points
1 x BIOS Switch

reply to koitsu

OT. A friend from Sweden just left my house to head back home...

The fact that they label it PCIE8 makes me wonder although someone already mentioned its not a factor at this time.

Any recommendation on software that displays this information. I will give SIW a try later.

Ok I guess I will make due with the 2 PCIe x1 and the PCIe x4.
BTW. My plan is to connect HDMI streaming cards to connect cameras and use software as a switch. At this point up to 3 cameras is enough.

reply to me
FWIW: Running your video card at x8 wont slow it down.