Anyone try 8800gtx SLI with 8x/8x pci-e slots? going to try this on a DFI nforce4

R

RyanLucier

Gawd
Joined
Nov 23, 2006
Messages
667
So.. I got a single 8800gtx and it's the cats pajamas... but im also running a dell 30" LCD (for work, of course ;) ) and most games run great, but not all can run at 4x or even 2x fsaa. Sooo... I'm going to grab another 8800gtx and a silverstone zeus 850w power supply.

Anyone have any experience with 8800gtx SLI on any AMD 939 boards? Or anything other than a conroe for that matter?

I'm hoping the 8x/8x slots won't incur too much of a performance penalty... I would rather not upgrade to a conroe if I don't have to, considering i have a athlon x2 1mb @ 2.6ghz.

Would be a GREAT idea for the [H] to investigate.. assuming they use apples to apples and not that 'best playable settings' homoness ;)
 
Not GTX, but I've got a couple GTS boards on an eVGA NF41 SLI and they are running with no issues aside from being heavily CPU bottlenecked.







Only until I get my C2D stuff later this month.

System in my sig. :) Really bottlenecked by the CPU... 3DMark 06 scores are 8500 ish with a single GTS, 9800 ish with both of 'em in SLI mode.
 
Blue Falcon said:
Only until I get my C2D stuff later this month.

System in my sig. :) Really bottlenecked by the CPU... 3DMark 06 scores are 8500 ish with a single GTS, 9800 ish with both of 'em in SLI mode.
Click to expand...

Um... an X2 3800+ isn't going to bottleneck *anything* for a while... I mean, its score in 3dMark06 might not be as good, but that is pretty much the only place you'll notice the difference.
 
thats what i figured, i am running at 2560x1600 @ 4x fsaa or higher, at maximum detail.. i kinda figure the cpu is the last thing i really need to worry about.

I'd just rather not dump $1000+ into a cpu that may only give me higher "maximum" framerates.. who cares about maximums.. its all about minimums. I am running vsync generally, which means 60fps max anyways.

As long as my minimums kick ass, i'll be happy ;)
 
As far as I know the 8800gtx will not run in a x8 slot, it has to be 16x slot for it to run I am just going by what I seen a few weeks ago when I got mine so it may not be true, but it did say that it will not run in a 8x slot.

Maybe something todo with the drivers that will stop it running properly ? but personally, i wouldnt run one in a 8x slot, get a asus a8n 32 mobo and run them full speed if you need sli.
 
EVIL-SCOTSMAN said:
As far as I know the 8800gtx will not run in a x8 slot, it has to be 16x slot for it to run I am just going by what I seen a few weeks ago when I got mine so it may not be true, but it did say that it will not run in a 8x slot.

Maybe something todo with the drivers that will stop it running properly ? but personally, i wouldnt run one in a 8x slot, get a asus a8n 32 mobo and run them full speed if you need sli.
Click to expand...

I believe the slot is 16x hardware capable, but it just runs at 8x speeds. What the OP is asking is if the bandwidth limitation will make a difference. I'm thinking if it is in fact a limiting factor, it wont be by much, as any previous card could not saturate the 8x bandwidth.
 
I dont see this being a problem at all. Unless the OP wants x16AA, but you can do SLI x16AA in x8/x8 SLI slots. Otherwise you could just do x8AA and x16AF, (8+8=16). And Blue Falcon doesn't seem to be having problems thus far.
 
well I ended up getting the second 8800gtx, and at 2560x1600, CS:Source runs at 100fps at 16xQ / 16xAF / SSAA / high quality texture & no optimizations & everything set to maximum in both the nvidia control panel and the game's options.

Thats awesome.. however I'm finding a lot of other games are really having lackluster performance. I'm going to investigate further into the 8x/8x versus 16x/16x multipliers, because my performance in other games doesn't seem too awesome at all. Company of Heroes with max details runs like a dog at 2560x1600 even with 2x FSAA & SSAA.

Neverwinter Nights 2 runs like complete ass, it is slow as molasses, less than 30fps.

BF2142 runs pretty good, but I can't run 16xQ AA / 16x AF without hiccups all the time. Same situation for Hitman.

Basically the short of it is i'm finding some games run like total dogshit while others run fantastic.. I can't help but think it has to do with the cards being bottlenecked. I really doubt its the CPU bottlenecking the cards because even though its only a 2.6ghz athlon X2, im running at 2560x1600 so its really a pixel-pushing issue more than it is cpu holding everything back. Besides, im not complaining because my games aren't running at 120fps.. they're running less than 50-60fps - highly doubtful that the cpu is limiting the framerates.

Would be a great thing for hardocp to investigate!
 
also, i tried a total format/reinstall of windows and installed the 97.44 drivers fresh, and the performance didn't change.
 
I think you're just asking way too much of your hardware. You can't expect flawless performance at 2560x1600 in recent releases, no matter what your're running. A couple of those games may have legitimate technical issues, but for the most part I think you're being a bit unrealistic.
 
LuminaryJanitor said:
I think you're just asking way too much of your hardware. You can't expect flawless performance at 2560x1600 in recent releases, no matter what your're running. A couple of those games may have legitimate technical issues, but for the most part I think you're being a bit unrealistic.
Click to expand...

I sorta agree with this... 2560x1600 with a few levels of AA are going to reduce your performance down to the mid 40-50's in most games...

But, you know... We're still using these god awful drivers, so I'm sure we'll all be seeing better performance in a month or two, with the new FWX drivers.
 
Don't forget, some game simply do not see much improvement with SLI and in fact, some games run BETTER on a single card.
 
I have an Asus nForce4 M/B, it's the A8N-SLi Premium, and two eVGA 8800GTS's in SLi. I have seen nothing but mind blowing performance. Going from 7800GTX SLI to this was nothing short of amazing. I run every game I play at 1600x1200 (Limited by my monitor) x16AA/x16AF and my FPS never drops below the 80's.

Edit: @ RyanLucier; I think the driver are holding back some of the cards performace, because there are people out there that are running those settings fine and some are having trouble. The new drivers should yield better performance.
 
ya.. i certainly think there's some driver anomalies, because these drivers don't even save the settings half the time when I apply them in the nvidia control panel.

That said, running 1600x1200 @ 16AA/16AF is nowhere near running 2560x1600 @ 16AA/16AF. I'm running double the pixels (1.9 million vs. 4.1 million pixels). I think its quite possible the 8x/8x slots are holding back the cards, but I haven't got a 16x/16x motherboard to verify this theory.

I did some benchmarking in company of heroes and here are my numbers. Everything in the game was completely maxed out when I did this, running at 2560x1600:
Gamma: Yes
FSAA: 2x
TSAA: SSAA
Vsync: No
SLI enabled: Yes
Quality image settings in nvidia control panel, application default AF
Min: 28.5 Avg: 98.1 Max: 191.0

Gamma: Yes
FSAA: 4x
TSAA: SSAA
Vsync: No
SLI enabled: Yes
High-Quality image settings in nvidia control panel, application default AF
Min: 35.4 Avg: 73.2 Max: 176.0

To me, these numbers don't seem all that impressive, and the game really doesn't run very well at these settings. Keep in mind this isn't 16x FSAA, just 4x at most.
 
PWMK2 said:
Um... an X2 3800+ isn't going to bottleneck *anything* for a while... I mean, its score in 3dMark06 might not be as good, but that is pretty much the only place you'll notice the difference.
Click to expand...


Nonsense; the x2 gets stomped utterly by a core2duo @ 3.2+ghz. STOMPED. And it makes a huge difference in framerates in many games.
Re: the shitty framerates...try it without SLI and i expect you'll get BETTER framerates. COH in particular runs like complete shit on SLI setups; the lack of consistent performance from SLI is what made me ditch my 7800gt's and get my 8800gtx.
 
well i dont agree that SLI lowers performance in CoH because my scores for CoH without sli are as follows:

Gamma: Yes
FSAA: 2x
TSAA: SSAA
Vsync: No
SLI enabled: NO
Quality image settings in nvidia control panel, application default AF
Min: 8.0 Avg: 54.4 Max: 122.0

Gamma: Yes
FSAA: 4x
TSAA: SSAA
Vsync: No
SLI enabled: NO
High-Quality image settings in nvidia control panel, application default AF
Min: 6.00 Avg: 39.3 Max: 104

They are slower than the scores WITH sli.
 
could be pci-e lane saturation, but more likely to be some cpu limited issues... managing those two 8800GTXs is no easy task... I bet your performance will increase noticably with faster cpu performance.. try OCing your cpu more and benching it out.. just for grins. :)

edit: what would really kick ass if someone would make a mobo with a pci-e lane bw useage meter.. some leds like on the corsair pro modules. :D but one which really shows when your pushing max bw.. those leds on the corsair moules light up to the red with any memory activity.. same concept, but more accurate metering.
 
headless said:
Nonsense; the x2 gets stomped utterly by a core2duo @ 3.2+ghz. STOMPED. And it makes a huge difference in framerates in many games.
.
Click to expand...



A "stock" X2 3800+, yes, to an "overclocked" C2D ????? OF COURSE.....that's obvious.

Overclock that X2 to 2.6ghz or so, and in REAL games at high res and IQ settings, you will NOT see the "stomping" you speak of.

Keep the comparisons valid dude.....
 
Check out this [H] review of the P5N-E SLI...


From what Kyle said in his conclusions....

Kyle Bennet said:
Many will point to this board as being a “8X8 SLI Only” motherboard and it is, but we have yet to find anywhere that we have seen real world differences in performance. The 8X8 SLI configuration only comes up short when running canned benchmarks in our experience, so if you are a benchmark type of guy, you will want to stick with the 16X16 SLI boards.
Click to expand...


It seems like going 8x/8x with 2 8800GTXs doesn't really have a huge effect on performance. The biggest hit will come with using the X2. Even when both are overclocked, the C2D does a much better job in managing 8800GTXs in SLI than it's AMD counterpart.
 
Yep.. but I think it's a little early to say for sure that it will never be an issue... DX10 games are supposed to be way more video card bound than cpu bound, so the need for adequte bw for peer-to-peer writes (card's communicating acorss the pci-e bus) may increase there.. but only time will tell.. the more I think about the more I think it will not be an issue tho.. but playing devil's advocate with myself a little.
 
btw to the OP. i had two 7900gt's in SLI. I ran COH with my SLI setup and framerates were crap. I couldn't figure it out of for the longest time. I was re-installing drivers to no avail. I did a quick search and i found out that you have to turn off this one setting in the game that messes it up if you have an SLI setup. I can't remember what it is exactly since i don't have my SLI setup anymore, i upgraded it to a 8800gts. But there's a setting that you can turn off on COH that should improve your frame rates. I'll see if i can check when i get home later.
 
well im noticing kinda crappy performance in most games.. not just any particular game really... I just am not experiencing a huge jump from 1 8800gtx @ 16x PCI-E to 2 8800gtx's @ 8x/8x PCI-E.
 
I think it has more to do with your cpu, and possibly some cpu/memory bw limitations of the nf4 chipset, than your pci-e lanes.. I read some posts on XS where people's tests show that getting ddr2 modules to 1.1ghz (with loose timings) showed decent improvements in bench tests over running them at 800mhz with tighter timings, when running two 8800GTXs in SLI.. it really puts a big strain on the system's memory system as well as cpu.. two 768mb cards with 128 shaders each.. that's a lot of graphics processing power to support...
 
You must log in or register to reply here.
Back
Top