PCI-E board

[noexpert]

Hi all

I need some help my friend has motherboard with a PCI-E slot that has only x8 speed instead of x16. If he decides to get a new graphics card will it work. Also if it will work will he be at a significant disadvantage than somebody who is using a pci-e x16 slot?

So will he see a noticeable difference when playing games like a loss in frame rates than what he should be getting if was to be using a pci-e x16 slot? Will games be slower than it should be? Will this pci-e x8 slot cause a bottleneck?

Sorry i can't tell you the name of the motheboard, i can't remember the model but it is an ASUS motherboard.

Thanks

 

[Oofki]

Yes it will be a bottleneck IF you can find a card to fit. They only make Pci-e 16x and 1x cards so he would have to get an 1x. The best with that is probably an x1550.

 

[noexpert]

Are you saying the PCI-E x8 slot is incompatible with mainstream video cards, that it won't even fit and run PCI-E x16 video cards? Just to be clear

I thought a PCI-E x16 card would work but only run in x8 speed, am i mistaken?

 

[chookman]

The big question is....

Is it a 16x slot length...

OR 8x slot length

 

[Crashman]

Yeh, some slots are x16 but have only x8 pathways...and there's a third option: The x8 length slot with the "open" end that allows the remaining portion of a card to hang out.

 

[noexpert]

Here is an image of the mobo, the PCI-E slot is black, it looks similar length size to a blue PCI-E x16 slot but i'm not sure.
http://img.xcomputer.cz/ImgW.asp?cd=AC305g&fd=f3

Does this slot look ok for a pci-e x16 card.

So what do you think?

I'd really like to know thanks

 

[Crashman]

That will hold any PCIe graphics card you want to put into it.

 

[noexpert]

Oh thats a relief thanks for letting me know.

So i just want to bring up a final question to this topic that was in my first post, will the performance be significantly reduced, like will the be a real world frame rates performance drop when playings games in x8 mode as to opposed a card running in pci-e x16 mode?

Is it worth buying a card for a pci-e x8 slot or will it be unnoticeable?

Thanks a bunch

 

[chowner]

No not even the 8800 ultra can utilize the bandwidth of pci 8x

 

[rammedstein]

No not even the 8800 ultra can utilize the bandwidth of pci 8x

i'm glad you are confident,i know 2 2900XTs can saturate 2x 8x easily though, i overclocked my pci-e slots and saw a drastic improvement (pci-e from 100->150mhz,8x slot -> "12x slot") because of the higher bandwidth, and also, so far i have seen no i'll effects of my pci-e bus being overclocked... (maybe it is only them 2 sets of pathways?)

 

[noexpert]

Ok i found out the actual motherboard model it is an Asus M2N-MX SE

The asus website if you read says it has a pci-e x8 bus
http://uk.asus.com/products.aspx?l1=3&l2=101&l3=345&l4=0&model=1647&modelmenu=1

but newegg website specification says it has a PCI-e x16 slot
http://www.newegg.com/Product/Product.aspx?Item=N82E16813131183R

which one is it?

 

[Crashman]

A PCI-Express x16 slot can be connected to an x8 bus.

 

[chookman]

Asus website labels the MAX pci-e lanes as x8 (the slot runs at PCI-e x8)
The Newegg says PCI-e x16 "Slot" this refers to the physical length

Any GPU you buy will work in this slot, it will run on 8 lanes instead of a full 16 lanes on a x16 slot.

 

[chookman]

chowner

No not even the 8800 ultra can utilize the bandwidth of pci 8x

Whats the point of making cards 16x if they cannot even flood enough data to a 8x? this would just increase the cost to create the card for no gain.

And why if we cannot flood a 16x slot are we going to PCI-e 2.0 which theoretically doubles the bandwidth?

rammedstein

i overclocked my pci-e slots and saw a drastic improvement (pci-e from 100->150mhz,8x slot -> "12x slot" )

You should see an improvement because the PCI-e interface is running at a faster speed pushing more bandwidth through faster on the 8 lanes. These cards are designed for 16 lanes and anything less than that should have a performance impact because you are lowering the bandwidth available to the card for transfer data streams. I hope the "12x slot" was in inverted commas because its theoretically the bandwidth of a 12 lane slot. Because you can NOT increase the number of lanes on a PCI-e slot by increasing the frequency at which it runs, it will only effect the lanes that are present.

 

[Crashman]

People weren't seeing a noticable performance difference between x8 and x16 until after the 7800 series came out, and then it was barely noticeable. It becomes more pronounced with 8800 series cards, but he's not likely to use anything faster than an 8600 series on such a motherboard.

 

[Gravemind123]

chowner

No not even the 8800 ultra can utilize the bandwidth of pci 8x

Whats the point of making cards 16x if they cannot even flood enough data to a 8x? this would just increase the cost to create the card for no gain.

And why if we cannot flood a 16x slot are we going to PCI-e 2.0 which theoretically doubles the bandwidth?

The reason we are going to PCI-E 2.0 is more for the fact that it supports more power being transferred over the bus. The speed of x16 has hardly reached the point of being fully used. We switched off of AGP before we ran out of bandwidth on it, so switching to PCI-E 2.0 is the same sort of thing. 8800s bottleneck very little off an x8 slot over an x16, and X1950XTX pretty has no performance loss.

 

[noexpert]

Asus website labels the MAX pci-e lanes as x8 (the slot runs at PCI-e x8)
The Newegg says PCI-e x16 "Slot" this refers to the physical length

Any GPU you buy will work in this slot, it will run on 8 lanes instead of a full 16 lanes on a x16 slot.

Ok thanks a lot for clearing up that confusion up and yes my friend is unlikely be running anything too powerful with this mobo, something like a 8600gt or 7900gs of that kind.