2-way SLI on Maximus V Extreme - best slots 8x/8x or 8x/16x?

[feniks]

I am looking at ASUS MVE manual and it seems that for 2-way SLI ASUS proposes using Intel CPU native bandwidth for both cards (8x/8x natively) using slots PCIe3.0_1 (top first) and PCIe3.0_2B (third from top). I know that switches/bridges may cause some lag, so it makes sense *IF* each of cards doesn't exceed the PCIe3.0 8x bandwidth (I think 670 2GB cards don't but I am unsure of it).
Also this configuration allows for better air flow between cards which probably matters if one relies on air cooling ... I don't, both cards are water cooled.

however I see there is also another config possible which is based on 3-SLI configuration and for 2-SLI it would suggest using both top first and second slots, PCIe3.0_1 & PCIe3.0_2A respectively for x8/16x.

tomorrow I will be installing my second 670 2GB for 8x/8x config for now and I hope it works fine (no lag related to PLX chip switching).

does anybody have some benchmarks comparing same cards and CPU clock (and memory) running 2 cards in each of mentioned configurations?

Thanks!

[feniks]

yeah, what you quoted seems true (you being an example).

so to sum up, you have 2 cards, each taking 3 slots space due to oversized cooler and you need a sound card installed too ... let's see.

the only way (with air cooling of yours) I see it happening is to use primary card in the top most slot and secondary in the bottom most (if your case allows for such setup) and place the sound card in then exposed PCIex4_1 slot. a flexible or 4-way SLI bridge should cover cards in such setup omitting the sound card.

however, if your case doesn't provide the space necessary under the bottom most slot then I think you are out of locuk with that air cooling, but you can always go water and enjoy thin cards again and much better temps ... and silence 😉

rog-classified wrote:
Hey guys. My question looks stupid i know but have to ask. If i install first gtx680 in pcie x16/x8 (1) first slot and the secant gtx680 in pcie x8 -2b(black) can i use the last pcie x8 (4) for my asus xonar phoebus. Because In MAXIMUS V EXTREME manual 1.2.5(online) , it says - "PCIe 3.0/2.0_x8_2B slot will be disabled when PCIe 3.0/2.0_x16_2A, PCIe 3.0/2.0_x8_3, PCIe 3.0/2.0_x8_4 slots are occupied" xonar phoebus card is already in pcie x8 (4) slot. it meen my 2b slot is disable? cant i mount second card to 2b. im using3 slot card and only can use 2b slot. any one can give me a advice on this cause second card on the way and i don't wanna open it if it cant use. freaking manual make me nuts.

[rog-classified]

Thanks mate. it mean the pcie x8 -2b(black) slot disable because of phoebus in pcie x8-4 (last slot). bad. I read that only pcie x16/x8-1 slot and pcie x8- 2b are native . My case is cosmos 2 and have space but 120m sli brig is not long enough. I paid near 200 for sound card and razer taimat 7.1 now i cant use those.wtf:(

feniks wrote:
yeah, what you quoted seems true (you being an example).

so to sum up, you have 2 cards, each taking 3 slots space due to oversized cooler and you need a sound card installed too ... let's see.

the only way (with air cooling of yours) I see it happening is to use primary card in the top most slot and secondary in the bottom most (if your case allows for such setup) and place the sound card in then exposed PCIex4_1 slot. a flexible or 4-way SLI bridge should cover cards in such setup omitting the sound card.

however, if your case doesn't provide the space necessary under the bottom most slot then I think you are out of locuk with that air cooling, but you can always go water and enjoy thin cards again and much better temps ... and silence 😉

[rog-classified]

Thanks mate. it mean the pcie x8 -2b(black) slot disable because of phoebus in pcie x8-4 (last slot). bad. I read that only pcie x16/x8-1 slot and pcie x8- 2b are native . My case is cosmos 2 and have space but 120m sli brig is not long enough. I paid near 200 for sound card and razer taimat 7.1 now i cant use those.wtf:(

feniks wrote:
yeah, what you quoted seems true (you being an example).

so to sum up, you have 2 cards, each taking 3 slots space due to oversized cooler and you need a sound card installed too ... let's see.

the only way (with air cooling of yours) I see it happening is to use primary card in the top most slot and secondary in the bottom most (if your case allows for such setup) and place the sound card in then exposed PCIex4_1 slot. a flexible or 4-way SLI bridge should cover cards in such setup omitting the sound card.

however, if your case doesn't provide the space necessary under the bottom most slot then I think you are out of locuk with that air cooling, but you can always go water and enjoy thin cards again and much better temps ... and silence 😉

[feniks]

no probs, I understand your pain.

in MVE box you should have a 4-way SLI bridge, 3-way SLI and 2-way flexible one. the 4-way bridge (solid) should fit catching the first and last slot just right, no?

[rog-classified]

yes but unfortunately 4 way sli brig(solid) cant mount on a 3slot card because it has the black connectors and they make them for 2 slot cards. i ask asus to use second pcie slot and last pcie slot for sli and first slot for sound card, but they say it wont stable. im going for 690 try to sell my 680. no option:(
(

feniks wrote:
no probs, I understand your pain.

in MVE box you should have a 4-way SLI bridge, 3-way SLI and 2-way flexible one. the 4-way bridge (solid) should fit catching the first and last slot just right, no?

[feniks]

what connectors do you mean? the double connectors on 3-way or 4-way not good for 2-way SLI?
I used 3-way and 4-way solid bridges on 2-way SLI before in past many times, it works normally, hell SLI used to work even without a bridge at all LOL (took around 5% penalty though).

... or rather you mean your cards have only a single connector for SLI? sorry I'm confused. a bit.

also a small update on my part, I moved my 670 SLI to 8x/16x config and it works great, now using slots PCIe3.0_1 & PCIe3.0_2A (sandwich setup). temps of PLX went higher up to 50C at idle versus former 30ish C when it was not in use before. I like it much better this way somehow, feels more natural to me ... and by looking at it, now the bottom slot looks like it want a 3rd card in there hehe ... I wish ...

[rog-classified]

i mean the solid sli brig have the connecters to connect to the vga card. because my vga card is(asus gtx 680 d2top) big and the second connecter slot of the solid sli brig touch vga cards upper part and cant connect to the card the.

feniks wrote:
what connectors do you mean? the double connectors on 3-way or 4-way not good for 2-way SLI?
I used 3-way and 4-way solid bridges on 2-way SLI before in past many times, it works normally, hell SLI used to work even without a bridge at all LOL (took around 5% penalty though).

... or rather you mean your cards have only a single connector for SLI? sorry I'm confused. a bit.

also a small update on my part, I moved my 670 SLI to 8x/16x config and it works great, now using slots PCIe3.0_1 & PCIe3.0_2A (sandwich setup). temps of PLX went higher up to 50C at idle versus former 30ish C when it was not in use before. I like it much better this way somehow, feels more natural to me ... and by looking at it, now the bottom slot looks like it want a 3rd card in there hehe ... I wish ...

[stackoverflow13]

Well from my setup I can only advise the following: I have 1 in the top slot & 1 in 2b (3rd slot) I then have an asus card in slot 5 (2nd from last). If I move my souncard to any other slot (bottom) it disables the 2nd vid card.

[feniks]

stackoverflow13 wrote:
Well from my setup I can only advise the following: I have 1 in the top slot & 1 in 2b (3rd slot) I then have an asus card in slot 5 (2nd from last). If I move my souncard to any other slot (bottom) it disables the 2nd vid card.

yeah that would work too, but he can't do that with oversized coolers (each card takes 3 slots).

[rog-classified]

cant do. 2 cars take 6 space . sound card can only mount in last slot. even i do so it not gonna work because 2b.

stackoverflow13 wrote:
Well from my setup I can only advise the following: I have 1 in the top slot & 1 in 2b (3rd slot) I then have an asus card in slot 5 (2nd from last). If I move my souncard to any other slot (bottom) it disables the 2nd vid card.