[SOLVED] PCI 16x Expansion slot question

Whirlingdervish

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Hi everyone,

I have an older Gigabyte GA-x58a UD3r v2 motherboard.

I’m considering acquiring an M.2 SSD drive which would be used through an adapter piece into one of the 2x PCI 16x slots.

Because of the physical space that my video card requires, to bring in the adapter card, I’ll have to move my video card to the 2nd slot and install my SSD drive to the first slot.

Does anyone expect there will be any problems with this order of the cards = SSD in slot one, video card in slot two?

I have heard that when you fill both slots, the speed of both slots might be halved... Is there any truth to this? What limitations might I encounter if switching slot order of the two cards?

Will there be any bios adjustments that I will need to make to ensure both cards will be operational?

Thoughts and ideas are appreciated!!
 
Solution
This. You will lose half the speed of the drive due to the bus, you may lose some speed on your video card (although only the latest fastest cards will take advantage of 16x over 8x) and you won't be able to boot from it anyway. Save yourself money and aggravation and buy a nice SATA SSD.
One cautionary note: you may have problems getting drives installed on the PCIe add-in card to be made bootable if your motherboard BIOS can't recognize the attached drive.

Also, even if you do drop the PCIe bandwidth from 16x to 8x the impact on GPU game performance will be negligible if not nil. Other GPU compute applications may have greater impact, but that's very dependent and still going to be quite small at any rate.

It might impact drives on the PCie SATA add-in card, but you'd need more than 2 NVME drives on the card since PCIe NVME cards utilize 4 lanes only, each.
 
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Whirlingdervish

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Here is the adapter I’m considering...

GODSHARK NVME Adapter PCIe x16 with Heat Sink, M.2 SSD Key M to PCI Express Expansion Card, Support PCIe x4 x8 x16 Slot, Support 2230 2242 2260 2280, Compatible for Windows XP / 7/8 / 10 https://www.amazon.com/dp/B07R4XPPCX/ref=cm_sw_r_cp_tai_pjKODbK5AC4SE

I can’t use the x16 slot 2 for the M.2 because the size of the video card makes using slot to impossible, therefore I would have to move the video card to slot 2 and use the drive in slot 1.

All these things considered, do you think that I would be good to go by doing this, and get better performance, rather than just buying a traditional SSD?
 

Wolfshadw

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No, you'd make life a lot easier just by purchasing a traditional SATA SSD.

...and your motherboard has four PCI-Ex16 expansion slots (unless you told us the wrong one). Install the adapter in the lowest PCI-Ex16 slot (PCIEx8_2 if I recall correctly) and don't move the graphics card. It's not going to need all the bandwidth of an x16 slot anyway.

-Wolf sends
 

Whirlingdervish

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Thank you for your suggestions!

My board has 2 of each, x16 and x8... The video card is so large that it covers one x8 and is very close to the second x16. Even the lower X8 may have obstructions.

I’ve heard that if I use x8, I will half the speed of an M.2. Still better than SATA SSD, from what I hear....

I will be use predominately for audio and video editing.

https://drive.google.com/file/d/1FPCSXSy_idW8w8xUAazDEyifOjS8a_Cx/view?usp=drivesdk

What makes you say I would be better off with a traditional SSD?

Thanks again!
 

Whirlingdervish

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One more bit of confusion...

The photo of the converter piece from Amazon has a different pin array than the slot. Is this to be expected? Even though it looks different, will it still fit in the slot?
 

Whirlingdervish

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So, if I may, let me see if I have this all straight…

If I buy a Crucial 1GB M.2 NVMe drive, and use it inserted into an adapter PCI card, this is what I should expect:

  • Half the read/write speed, since my PCI only runs at 2.0 capacity…
  • Maybe even half of that less, considering that I may have to bump the drive down to a lower level x16 slot, or an x8 slot?

if this is indeed the case, and we will average the R/W speeds of that drive at roughly 1500, if one does the math, the drive may not perform any better than a traditional crucial drive, which R/W about 500 MB/S anyway.

Am I off on any of these deductions? I’d just like to get some final opinions before I plunk down the money for this drive, and cash that I don’t actually have! :)
 

Wolfshadw

Titan
Moderator
The M.2 cards will only access four of the available PCIe lanes, so while you can expect half speed from using PCie 2.0 vs PCIe 3.0, running it in an x8 slot vs an x16 slot is not going to make any difference.

Of course, this does not take into account any loss of performance due to the adapter.

-Wolf sends
 
This. You will lose half the speed of the drive due to the bus, you may lose some speed on your video card (although only the latest fastest cards will take advantage of 16x over 8x) and you won't be able to boot from it anyway. Save yourself money and aggravation and buy a nice SATA SSD.
 
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