ASUS Rampage IV Extreme PCI-E 3.0 Support

[Nic88]

This is actually a Z77 ASUS Maximus V Gene.
So basically this mobo won't support 3-SLI at full speed PCI-E 3?
"I 'get' higher AA values and etc so get/buy whatever you want." - Apologies, I didn't get this sentence.

 

[jaquith]

ASUS Maximus V GENE - http://www.asus.com/Motherboards/Intel_Socket_1155/Maximus_V_GENE/#specifications

No there's no 3-WAY anything on the ASUS Maximus V GENE Z77 it is a 2-WAY SLI/CF Z77 @ x8/x8 PCIe 2.0/3.0 depending on your CPU AND GPU(s). Also, it's an mATX MOBO not a full ATX or EATX so there's no way to (fit) more than (2) GPU's in greater than double width configuration.

The IB is perfect to 2-WAY GTX 680 support and after that it gets 'fuzzy' 3/4-WAY SLI is IMO best on the X79 platform with nVidia and clearly better for 3/4-WAY HD 7000 series; no 'hack' required.

If you want a IB + Z77 that offers up to 4-WAY SLI via PLX chip (aka 'splitter') then look at the ASUS P8Z77 WS - http://www.asus.com/Motherboards/Intel_Socket_1155/P8Z77_WS/#specifications then remember you're funneling those GPU's bandwidth down to the equivalent PCIe 2.0 x8/x8/x8/x8 and potentially a tad of latency.

The following is NOT from ASUS Maximus V GENE:
2 x PCIe 3.0/2.0 x16 (dual x16) *1
1 x PCIe 3.0/2.0 x16 (x8 mode) *1

The following IS from ASUS Maximus V GENE:
2 x PCIe 3.0/2.0 x16 (x16 or dual x8, red) *2
1 x PCIe 2.0 x4 (black)
1 x mini-PCIe 2.0 x1 *3

 

[Nic88]

Well, that explains it. Thanks for your help mate.
One last question: what does "2 x PCIe 3.0/2.0 x16 (x16 or dual x8, red) *2" mean?

 

[jaquith]

Regarding:
2 x PCIe 3.0/2.0 x16 (x16 or dual x8, red) *2

*2: PCIe 3.0 speed is supported by Intel® 3rd generation Core™ processors.

2 x PCIe 3.0/2.0 x16 (x16 or dual x8, red) - those are 'shared' PCIe slots to the PCIe 3.0/2.0 x16 slots, in other words: 1. shared slots never carry in this case the full x16 lanes (lower PCIe Slot), 2. once occupied PCIe 3.0/2.0 x16 + PCIe 3.0/2.0 x8 = both (shared) PCIe slots receive x8/x8 PCIe lanes of PCIe 2.0 or PCIe 3.0 depending upon the Lowest speed of either the CPU or GPU i.e. slowest wins.

Simpler example - Assume IB + GTX 680(s):
1 GPU/single: GTX 680 = PCIe 3.0 x16 lanes
2 GPU's/SLI: GTX 680 = PCIe 3.0 x8 lanes per GPU

ALL LGA 1155 are 16 Lanes of PCIe to the GPU(s), the variable is whether it's PCIe 2.0 bandwidth or PCIe 3.0 bandwidth.

Example:
x8 PCIe 3.0 = x16 PCIe 2.0 ; bandwidth

 

[Nic88]

Does this mean that with such mobo I won't be able to have a full PCI-E 3 2-SLI 680?

 

[jaquith]

If by 'full' you mean x16/x16 PCIe 3.0 then no. To be clear I am a PCIe lane snob and PCIe 3.0 x8/x8 is a ridiculous amount of bandwidth to the GTX 680 at ANY resolution.

 

[Nic88]

If by 'full' you mean x16/x16 PCIe 3.0 then no. To be clear I am a PCIe lane snob and PCIe 3.0 x8/x8 is a ridiculous amount of bandwidth to the GTX 680 at ANY resolution.

Thanks for all the info mate, it's been a pleasure!