PCIe 16x and Sli Video Cards

KD18 · 06-07-2008, 10:37 PM

In an article, I read that a second, slied video card actually runs at a slower PCIe speed, even if it's in a 16x slot. Since my pc's card is actually in my mobo's second video card slot (but not currently in sli mode), I was wondering if this same performance hit always applies to any mobo's second PCIe 16x slot. If so, I'll probably rearrange my case and slap it into the first slot, but I'd like to make sure that doing so would generate a performance boost before doing it. So, does anyone know if my current setup is experiencing a performance loss? Thanks

If it helps, I'm running on an ASUS A8N32-sli Deluxe with an Ati x1900xtx 512 mb card.

Nuk3m · 06-08-2008, 07:59 PM

lol i have the same setup except with ati xfire

<-- ASUS A8R32-MVP Deluxe w/ ATi x1900xtx 512 MB

btw, I think the board you have was intended for Nvidia cards. the MVP board was designed for ATi.

I have read that a second card wont run at full capacity because it has to communicate with the first card or something so it slows it down. not sure tho.

Innoc · 06-08-2008, 08:12 PM

Nukem is right on both counts. SLi is Nvidia oriented. The other "SLi-type" operation is "Crossfire" which is exclusive to ATi. Yes, the 2nd slot will not operate at full 16x speed for a number of reasons.

Frankly, I have never been convinced that dual graphics card setups are the best "bang for the buck".

greenday5494 · 06-08-2008, 08:14 PM

i think they're worthless, IMO. they proccess info a bit faster, but if you slap another card in there, it's sitll the same old card, with same old tech

Nuk3m · 06-08-2008, 10:26 PM

Well, you wont get better graphis, you will get better framerates. like, here is an example.

Sim City Societies I can run at Maximum graphics settings, at an 1680x1050 resolution, now it runs fine, except i get low fps, around 30 - 40. with a second card in theory it should be about 60 - 80 frames.

StrYdeR · 06-08-2008, 11:48 PM

But it wont cause in reality the cards are only using 8channels to throughput

greenday5494 · 06-09-2008, 01:50 AM

Quote:

Originally Posted by Nuk3m

Well, you wont get better graphis, you will get better framerates. like, here is an example.

Sim City Societies I can run at Maximum graphics settings, at an 1680x1050 resolution, now it runs fine, except i get low fps, around 30 - 40. with a second card in theory it should be about 60 - 80 frames.

doesnt matter, because that game sucks monkey balls anyways and isnt optimized at all

leilei · 06-09-2008, 05:35 AM

my pair of voodoo2s never failed me

Nuk3m · 06-09-2008, 09:59 AM

Quote:

Originally Posted by greenday5494

doesnt matter, because that game sucks monkey balls anyways and isnt optimized at all

Im just saying greenday.

פֿяαιп βαмαgεפ · 06-09-2008, 10:37 AM

Quote:

Originally Posted by greenday5494

doesnt matter, because that game sucks monkey balls anyways and isnt optimized at all

That's irrellevant, he's talking about the framerates.

Anyway, SLI, still has some hiccups IMHO, so I stay as far away from it as possible.

SomeOldGuy · 06-09-2008, 10:50 AM

I believe the newest Intel boards with the X38/X48 chipsets allow both PCIE 2.0 slots to run at the full 16X in SLI. For Nvidia, I think at least the 780i boards do this also. I'm not sure about the rest of the 700 series.

פֿяαιп βαмαgεפ · 06-09-2008, 11:52 AM

Quote:

Originally Posted by SomeOldGuy

I believe the newest Intel boards with the X38/X48 chipsets allow both PCIE 2.0 slots to run at the full 16X in SLI. For Nvidia, I think at least the 780i boards do this also. I'm not sure about the rest of the 700 series.

^like I said: Brand new board, brand new technology, just leave it develop for a while.

v3rtigo · 06-09-2008, 12:15 PM

Unless I'm mistaken the a8n32 (which I have as well) is an Nforce4 x16 which is supposed to prevent it from running on 8x when in SLI mode. I did read something about if you have one card, you should put it in the blue slot. It might be related to this, I don't know. But anyway, with an ATI card you can't go SLI/CrossFire on that board and as others mentioned, SLI is certainly no lifesaver.

Nuk3m · 06-09-2008, 06:41 PM

I can see the only possible gain from it would be opening the capability to not have to upgrade to a more expensive card. keep in mind cpus play somewhat into how well your game runs.

KD18 · 06-11-2008, 04:10 AM

Quote:

Originally Posted by v3rtigo

I did read something about if you have one card, you should put it in the blue slot.

Since my card is in the second slot (not the blue one), I'd definitely like to look into this. What source did you get this from, and, if what you believe actually is true, how much of a performance gain would I most likely obtain from switching positions? Thanks.

KD18 · 06-11-2008, 04:31 AM

hmmmm, according to my motherboard's manual, a single video card placement doesn't really affect performance; either one allows for PCIe x16. However, when in sli mode, one card really does run at x8, at least for this specific mobo. So, disregard my last question.

s0undch4s3r · 06-13-2008, 08:29 AM

I have SLI enabled 8800GT's.

The only benefit you will ever get is frame rates staying high at high resolution.
Your frame rates will not double.
You will get a better score on 3Dmark05 and 06 using SLI.

Also you can turn on AA and other video enhancing options and your frame rates should stay favorably high.

Like in Crysis I can run 1680 x 1050 with everything on high with AAx4 and my
average fps is 55.

Basically SLI is for high resolution, high quality rendering. Nothing more.

If you use low resolution like 1024 x 768 then you are not taking advantage of SLI. All you're doing is creating heat in your room.

פֿяαιп βαмαgεפ · 06-13-2008, 10:39 AM

Quote:

Originally Posted by s0undch4s3r

I have SLI enabled 8800GT's.

The only benefit you will ever get is frame rates staying high at high resolution.
Your frame rates will not double.
You will get a better score on 3Dmark05 and 06 using SLI.

Also you can turn on AA and other video enhancing options and your frame rates should stay favorably high.

Like in Crysis I can run 1680 x 1050 with everything on high with AAx4 and my
average fps is 55.

Basically SLI is for high resolution, high quality rendering. Nothing more.

If you use low resolution like 1024 x 768 then you are not taking advantage of SLI. All you're doing is creating heat in your room.

But you can play Crysis decentley with AA on with one GT, no?

06-07-2008, 10:37 PM	#1
KD18 Join Date: Jul 2007 Posts Rated Helpful 0 Times	PCIe 16x and Sli Video Cards In an article, I read that a second, slied video card actually runs at a slower PCIe speed, even if it's in a 16x slot. Since my pc's card is actually in my mobo's second video card slot (but not currently in sli mode), I was wondering if this same performance hit always applies to any mobo's second PCIe 16x slot. If so, I'll probably rearrange my case and slap it into the first slot, but I'd like to make sure that doing so would generate a performance boost before doing it. So, does anyone know if my current setup is experiencing a performance loss? Thanks If it helps, I'm running on an ASUS A8N32-sli Deluxe with an Ati x1900xtx 512 mb card.

06-08-2008, 08:12 PM	#3
Innoc Hitman 2 1 Actual Join Date: Mar 2007 Location: "Oscar Mike" Gametype: FPS or RTS (just say NO to MMO) Affiliations: Your Mom Posts Rated Helpful 8 Times	Nukem is right on both counts. SLi is Nvidia oriented. The other "SLi-type" operation is "Crossfire" which is exclusive to ATi. Yes, the 2nd slot will not operate at full 16x speed for a number of reasons. Frankly, I have never been convinced that dual graphics card setups are the best "bang for the buck". __________________ Mooga on Obama: He can cut taxes. Actually do something useful. Punch Nancy Pelosi in the face. Just to name a few. You eventually run out of other people's money to spend.

06-08-2008, 08:14 PM	#4
greenday5494 Holy shit, thats kerrigan! D&A Member Join Date: Sep 2007 Class/Position: D, whatever the team needs, usually engy Gametype: AvD Affiliations: None Posts Rated Helpful 1 Times	i think they're worthless, IMO. they proccess info a bit faster, but if you slap another card in there, it's sitll the same old card, with same old tech __________________ http://static.adrive.com/images/ads/...rbo_468x60.gif DAN MAPES!

06-08-2008, 07:59 PM	#2
Nuk3m Banned Join Date: Mar 2007 Location: New Jersey, USA! Class/Position: Scout / Offense Gametype: Capture the Flag Affiliations: :e0: Founder Posts Rated Helpful 0 Times	lol i have the same setup except with ati xfire <-- ASUS A8R32-MVP Deluxe w/ ATi x1900xtx 512 MB btw, I think the board you have was intended for Nvidia cards. the MVP board was designed for ATi. I have read that a second card wont run at full capacity because it has to communicate with the first card or something so it slows it down. not sure tho.

06-08-2008, 10:26 PM	#5
Nuk3m Banned Join Date: Mar 2007 Location: New Jersey, USA! Class/Position: Scout / Offense Gametype: Capture the Flag Affiliations: :e0: Founder Posts Rated Helpful 0 Times	Well, you wont get better graphis, you will get better framerates. like, here is an example. Sim City Societies I can run at Maximum graphics settings, at an 1680x1050 resolution, now it runs fine, except i get low fps, around 30 - 40. with a second card in theory it should be about 60 - 80 frames.

06-08-2008, 11:48 PM	#6
StrYdeR FFapper Join Date: Mar 2008 Location: Utah Posts Rated Helpful 0 Times	But it wont cause in reality the cards are only using 8channels to throughput

06-09-2008, 05:35 AM	#8
leilei o^_^o Join Date: Nov 2007 Class/Position: O Gametype: CTF Posts Rated Helpful 0 Times	my pair of voodoo2s never failed me

06-09-2008, 10:50 AM	#11
SomeOldGuy older than dirt Join Date: Mar 2007 Location: just east of the jug handle Posts Rated Helpful 9 Times	I believe the newest Intel boards with the X38/X48 chipsets allow both PCIE 2.0 slots to run at the full 16X in SLI. For Nvidia, I think at least the 780i boards do this also. I'm not sure about the rest of the 700 series.

06-09-2008, 12:15 PM	#13
v3rtigo Lock 'n Loll! Join Date: Sep 2007 Location: 2fort Class/Position: Scout, Spy, Sniper Gametype: CTF Posts Rated Helpful 0 Times	Unless I'm mistaken the a8n32 (which I have as well) is an Nforce4 x16 which is supposed to prevent it from running on 8x when in SLI mode. I did read something about if you have one card, you should put it in the blue slot. It might be related to this, I don't know. But anyway, with an ATI card you can't go SLI/CrossFire on that board and as others mentioned, SLI is certainly no lifesaver.

06-09-2008, 06:41 PM	#14
Nuk3m Banned Join Date: Mar 2007 Location: New Jersey, USA! Class/Position: Scout / Offense Gametype: Capture the Flag Affiliations: :e0: Founder Posts Rated Helpful 0 Times	I can see the only possible gain from it would be opening the capability to not have to upgrade to a more expensive card. keep in mind cpus play somewhat into how well your game runs.

06-11-2008, 04:31 AM	#16
KD18 Join Date: Jul 2007 Posts Rated Helpful 0 Times	hmmmm, according to my motherboard's manual, a single video card placement doesn't really affect performance; either one allows for PCIe x16. However, when in sli mode, one card really does run at x8, at least for this specific mobo. So, disregard my last question.

06-13-2008, 08:29 AM	#17
s0undch4s3r The guy you love to hate. Join Date: Mar 2007 Location: Under your bed Posts Rated Helpful 1 Times	I have SLI enabled 8800GT's. The only benefit you will ever get is frame rates staying high at high resolution. Your frame rates will not double. You will get a better score on 3Dmark05 and 06 using SLI. Also you can turn on AA and other video enhancing options and your frame rates should stay favorably high. Like in Crysis I can run 1680 x 1050 with everything on high with AAx4 and my average fps is 55. Basically SLI is for high resolution, high quality rendering. Nothing more. If you use low resolution like 1024 x 768 then you are not taking advantage of SLI. All you're doing is creating heat in your room.

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