Comments on: How to tell which PCI express slot I have https://dfarq.homeip.net/how-to-tell-which-pci-express-slot-i-have/?utm_source=rss&utm_medium=rss&utm_campaign=how-to-tell-which-pci-express-slot-i-have David L. Farquhar on technology old and new, computer security, and more Fri, 05 Nov 2021 03:55:02 +0000 hourly 1 By: Dave Farquhar https://dfarq.homeip.net/how-to-tell-which-pci-express-slot-i-have/#comment-56091 Fri, 05 Nov 2021 03:55:02 +0000 https://dfarq.homeip.net/?p=27000#comment-56091 In reply to Shirley Marquez.

Thanks for the specific examples!

]]> By: Shirley Marquez https://dfarq.homeip.net/how-to-tell-which-pci-express-slot-i-have/#comment-56090 Wed, 03 Nov 2021 14:19:46 +0000 https://dfarq.homeip.net/?p=27000#comment-56090 The higher end motherboard chipsets from AMD and Intel can reconfigure their allocation of PCI Express lanes. It might be true, for example, that if you have only one x16 card plugged in it will get 16 PCIe lanes, but if you plug in two cards each one will operate at x8.

That’s a key difference between the B450 and X470 AMD chipsets. The B450 would require each of the two slots to be permanently configured at x8, while the X470 can determine how many cards are plugged in when you power up the system and reallocate accordingly. A B450 motherboard with two x16 slots will not get optimum performance from a single graphics card, though the loss is only a couple of percentage points.

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