A question about PCIe x16

[mjurgilas]

So, i know that there are a lot of threads about this, but i need to make sure. My mother board is Asus P5kpl-AM it has a PCIe x16 slot for a video card. My current card is Asus GeForce 9600gt. I'm planning to upgrade since my budget is not that big i chose: http://www.msi.com/product/vga/N450GTS-MD2GD3.html#?div=Overview
Problem is it needs a PCIe x16 2.0 bus while mine is PCIe x16. Now i know it is backwards compatible, but as far as i saw it wont run that great on just a x16. My question is will the bottleneck be very noticeable ?

 

[itzdanielp]

I don't know what you have in the rest of your computer, but I am going to assume that the bottleneck will come from your RAM or possibly CPU before the PCIe Bus slows you down.

 

[mjurgilas]

I don't know what you have in the rest of your computer, but I am going to assume that the bottleneck will come from your RAM or possibly CPU before the PCIe Bus slows you down.

Well i got 2gb of ram (other 2gb stick died) and a intel quad core q400 processor which isn't that bad

 

[itzdanielp]

Your bottleneck (if there is one) will definitely come from your RAM before it bottlenecks the GPU

 

[mathew7]

As information, bandwidth wise: PCIe 1.0 x16 = PCIe 2.0 x8 = PCIe 3.0 x4
But the final GPU performance is not affected so much by this, especially on mainstream and budget cards.
Here is a test done with taped connector to force x8 and x4, which had a powerful CPU and GPU. One of the conclusions:

We also examined how much PCI-E 2.0 x4 (or PCI-E 1.1 x8, older motherboards) would affect the GTX 480. And the result coarsely put is "not much": 8%.

Just bear in mind this is still a powerful card even today. So your penalty would be even less.

 

[HostileDonut]

PCI-E x16 is equal to PCI-E 2.0 x8. You won't get more than a 2% performance decrease on the card, which is negligible. Your RAM would bottleneck you the most. What was the CPU? You said Q400, but a Qx400?