How much of a bottleneck is 4x PCI-E?

[crunchman]

Just realised the second slot on my POS mobo is only 4x, I had it in the full speed slot previously but moved it lower to reduce temps.

My card is a GTX 660, other parts of my system are i5 760 with 12 gigs of ram

How much of a drop in performance have I given myself by using 4x instead of 16x?

Cheers

 

[Jono8]

Probably not much of a bottleneck at all with just a 660.

 

[crunchman]

Cool, forgot to mention I pretty much run 4 monitors off it all the time.

Does that make a difference?

 

[pandem0nium]

I'd have a guess of 10 - 20 %

You'd be in the best position yourself to benchmark the card in each of the slots to measure the difference.

 

[crunchman]

Hmm might do that then, what's the best for benching atm?

 

[pandem0nium]

Unigine heaven or valley, 3d mark, some games have built In benchmarks like dirt 3.

 

[tbyeah]

It's usually none. So long as it's PCI-e 3.0, 4x is absolutely fine, and there is typically nil difference. If there is it's negligible.

 

[ubersonic]

It's usually none. So long as it's PCI-e 3.0, 4x is absolutely fine, and there is typically nil difference. If there is it's negligible.

IIRC his board is PCI-E 2.0 not 3.0

 

[Azza666]

Get a new mobo I'd say if you can spare the cash.

 

[LtMatt]

Probably around 5-10%, though not sure if four monitors will increase that or not, possibly.

 

[BaDBoY_uK]

If it's PCIE3.0, 4x is effectively PCIE2.0 8x and you'll be fine. I showed that recently with a dodgy 780

If it's PCIE2.0 x4, then you'll be losing some decent fps

 

[crunchman]

Motherboard is a BIOSTAR H55A+ socket 1156, it's PCI-E 2.0

So I ran 3d mark 11 with the sky diver test, I disabled all but one monitor for the tests

4x as it was:
11689 points

16x
11906

So not even 2% difference, thought that was a little weird so I opened up GPU-Z and it's reporting the card is only running at 8x?

I guess that could be some power saving feature

I think I may as well move the card back, but I'll wait a week or so and see how the temps are

 

[BaDBoY_uK]

4x as it was:
11689 points

16x
11906

I take it back. There's your answer. The next question is what would you get at PCIE 3.0 x16?

Try clicking the little ? next to where it reports the Bus Interface. Click full screen. Bottom left. What does it say there?

 

[crunchman]

Hmm it's saying GeForce 660 16x @ 4x


Haha can you get a PCI-E 3.0 board for socket 1156 ?

 

[breadturbo]

A little offtopic, but 12gb ram means you aren't running dual channel?

 

[crunchman]

This is what I'm running:

2x4GB and 2x2GB, that's dual channel isn't it? I got lost with components after DDR1 went

 

[ubersonic]

Hmm it's saying GeForce 660 16x @ 4x

Does it say that while running 3D? as it normally scales down when idle.

2x4GB and 2x2GB, that's dual channel isn't it?

Correct.