P67 pci express limitations

[7thWave]

Hi,

this is my rig:

2600k
MSI P67A GD55
Dell Perc 5/i (pci express x8)
(3 WD caviar black in Raid 0)
Radeon HD 5870

Due to the limitations of the P67 chipset which cannot handle two pci express devices at x16 each one, my 5870 runs at pci express x8.

I would like to know if putting the Dell Perc 5/i at pci express x4 (with adhesive tape) would get my 5870 back in business at pci express x16 ?

Thank you !

 

[TIGR]

You can try it, but I suspect that when both slots are occupied, they're automatically cut to x8/x8 regardless of how many lanes are actually being used. For what it's worth, W!zzard's 5870 review shows that you're only losing 2% average performance by being restricted to x8. Then again, if you're playing certain games at certain resolutions, the difference may be more significant.

Maybe someone else can give you a more conclusive answer; otherwise, try it and let us know.

 

[Bo$$]

try it, i dont think it will work but it is worth a shot. good luck man

 

[cadaveca]

Hi,

this is my rig:

2600k
MSI P67A GD55
Dell Perc 5/i (pci express x8)
(3 WD caviar black in Raid 0)
Radeon HD 5870

Due to the limitations of the P67 chipset which cannot handle two pci express devices at x16 each one, my 5870 works in pci express x8.

I would like to know if putting the Dell Perc 5/i in pci express x4 (with adhesive tape) would get my 5870 back in business a pci express x16 ?

Thank you !

No, this will not work. The slot the Perc 5/i is in needs to be wired to the chipset, and not the CPU, in order for this to be possible. I do not beleive that this is the case with your board. It is possible there is another slot, run off of the P67 PCH, that would allow what you are looking for, but I tihnk you'll probably need to look at another product, like the ASUS P8P67 Pro, which has a physical x16 slot on the bottom, wired in @ 4x with the P67 PCH.



This diagram shows how the PCIe works:

Usually the slots like the lower black one on the ASUS P8P67 Pro are limited to PCIe x4 due to other devices connected to the P67 PCH, like audio, USB 3.0 and such, even though there are eight lanes total available via the chipset, so don't expect to get more than a x4 and x16 setup on a single board. None that I am aware of offer X8 and X16.

Of course there are other products, like the Biostar Z68 board I reviewed, that are naturally x16/x4, and off no lane splitting from the CPU, so you might want to consider a product like that, too, which costs half what the P8P67 Pro does, but at the same time, is also a bit limited in features compared to the ASUS product.

 

[LAN_deRf_HA]

Wth. Just noticed I'm running in 8x on my EVO. The other cards are only 1x... retarded. If I move one down from the light blue to the black slot at the bottom will it run at 16x?

 

[TIGR]

Wth. Just noticed I'm running in 8x on my EVO. The other cards are only 1x... retarded. If I move one down from the light blue to the black slot at the bottom will it run at 16x?

Not to threadjack from the OP, but LAN, take a look at the specs from Asus (link), which tell you you lanes/slots layout. There might be more info in the manual, which you can download there too.

 

[cadaveca]

Wth. Just noticed I'm running in 8x on my EVO. The other cards are only 1x... retarded. If I move one down from the light blue to the black slot at the bottom will it run at 16x?

I know, it's a bit confusing. But I must ask, how come you are not running x1 cards in x1 slots?

And to answer your question, yes, if you have a card in the middle slot, it will force a x8 link to the top slot, while the bottom slot will not.

 

[7thWave]

Thank you guys for your answers. So, I tried and it doesn't work at all. While the Perc 5/i is at pci express x4, it is not recognized by the chipset. Then, this lovely message appears : "impossible to find a proper boot device".

I noticed that there was indeed less than 2% performance decrease between x16 2.0 and x8 2.0. But the techpowerup article concerning the 5870 is a little bit "old". It would be interesting to see this kind of review with actual gaming footage like Crysis 2, Battlefield 3 or RO2.

All these games run fine on my rig, but I am more or less "afraid" to think that the performances could be (even a little bit) better with the card running at x16.

 

[LAN_deRf_HA]

The board has only two 1x slots and one is blocked by any dual slot card.

 

[7thWave]

The board has only two 1x slots and one is blocked by any dual slot card.

Indeed, but ?

 

[cadaveca]

Indeed, but ?

Pretty sure he was aswering my question as to why he wasn't using a x1 slot.

 

[7thWave]

Ok.

 

[7thWave]

Hello guys,

Refering to the techpowerup article, I wouldn't see any difference between x8 and x16. Nevertheless, this article was made upon "old" graphic engines, and I don't know if it can be compared to the Frostbite 2.

I have been playing Battlefield 3 Open Beta since its launch until its closure and the performances on my rig were pretty good (1680*1050 - Everything set to ultra, no aa and aniso, no HBAO), but I would like to know if the performances could be much better with my Radeon running at its optimal bandwith (PCI-Express 2.0 x16).

Thank you very much for your answers.