Any PC build guru's out there ?

Sootchucker

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HI guys, looking for a bit of advice from the PC guru's out there.

I have a fairly elderly (but totally useable) desktop PC, that I built some years ago. It's based around an ASUS P8Z68V LX motherboard (socket 1155), with an Intel Core i5 2500k which has been overclocked for some years now to 4.5ghz. Oh and 16gb of DDR3 ram.

Everything working beautifully, but then last week I decided to upgraded both the case and install for the first time a GPU (an AMD Radeon RX 570). The upgrade went great and the RX 570 adds a much needed boost to my video editing and Photoshop/Lightroom editing. In fact in Geekbench 4 Compute tests, the score went from 17,831 to a massive (by my standards) 117,481, a 10 fold increase.

Now to my issue. My motherboard has a limited number of PCI / PCIe slots, and has:

2 x PCI Express 2.0 x16 slots (blue @ x16 mode, black @ x4 mode)
2 x PCI Express 2.0 x 1 slots
3 x PCI slots.


So I installed the Radeon GPU in the 1st PCIe x16 slot (the blue one), but as it's a double thickness card, it covers totally the second PCIe x 1 slot, and that's my problem. I currently have 2 PCIe x1 cards that I wish to use. The first is my Wifi / Bluetooth card which is sucessfully installed and working in the 1st PCIe x1 slot above the GPU. That meant my 2nd card (my USB 3.0 card, with an internal header to connect to the new case's USB 3.0 sockets on the front via a USB3.0 connector), couldn't be installed in the 2nd x1 slot below the GPU PCIe slot as the GPU covers it.

No problem I thought, these PCIe slots are all backwards compatible, so I installed the USB card into the 2nd PCIe x16 slot (the black one), which isn't affected by the GPU, but nothing happens. Windows 10 doesn't recognise any card installed either in device manager or by physically plugging in a USB stick into either of the two front case USB 3.0 sockets or the 2 USB 3.0 sockets which are on the back of the PCIe card rear bracket. The card I know worked flawlessly before when it was installed in the old case (but fitted into the 2nd PCIe x 1 slot which is now covered) ?

My questions therefore are:
  1. Does anyone know why it wouldn't work or be detected in the PCIe x16 slot (I thought these were all backwards compatible with x16, x8, x 4 & x1 cards) ?
  2. If I moved the GPU from the top X16 slot (the blue one), to the lower one (black), would that be a bad idea and would that really throttle back the GPU (this solution would uncover the 2nd "hidden" PCIe x1 slot). Even though the motherboard lists both of the large slots as PCI Express 2.0 X16, it seems to suggest in the subtext tha tonyl the blue slot has access to all 16 lanes and the black slot only has access to 4 lanes ? If that's the case, why isn't the second x16 slot just a x4 or x8 size slot ?
  3. Is there a better USB 3.0 (or USB3.1 Gen2) card that would work in the 2nd PCIe x16 slot (the black one) ?
Thanks in advanced.
 
Can't help with points 1 and 3 but for point 2, preference is always for the GPU to be in the x16 slot for maximum bandwidth.
If you put it in the other slot I believe you will half your bandwidth which then starts defeats the purpose.
 
My questions therefore are:
  1. Does anyone know why it wouldn't work or be detected in the PCIe x16 slot (I thought these were all backwards compatible with x16, x8, x 4 & x1 cards)
Some Asus motherboards have a PCI slot sharing the addressing with a Sata port meanng that you can use one or the other but not both at the same time.
 
Would this be a use for a PCI riser cable if there is another slot in the case(not mobo)?

(May be more expensive than a usb WiFi adapter mind).
 
Have you read the motherboard manual because I found that is the most important part of PC building
 
As an addition to stupar's explanation on point 2, the second slot is the full length so a second GPU can be used with whatever bridging scheme AMD or Nvidia use to link the two cards together. The reduced number of lanes is down to limitations of the chipset.

Have you tried swapping the wi-fi and USB cards to see if the problem is with the card or the slot?
 
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As far as I know both PCIe2 slots would work on your Video Card.
In my Z800s I have PCIe2 slots and my NVME M.2 SSDs run at the same speed whatever slot they are plugged in.
I think the only reason your M/B manufacturer may suggest you should us the blue one for a video card is that it has the retaining clip to hold the Video card in place better.
As for the USB 3 card have you installed the software for it and have you connected a power supply to it - all USB3 cards I have ever installed have always needed a power supply.
BTW I always install my USB3 cards into the smaller PCIe2 slots and they always run at full speed.
 
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