8600GT - SLI without bridge?

[sherpa]

Hello Friends

This is my first post to this forum. Although I hate to present my problems to people on first introduction, with due apologies I am forced to do the same now.

I purchased 2 8600 GT cards by Point of View recently to be used in SLI configuration on a MSI K9N Diamond Motherboard. The cards perform well individually, but, with the SLI Bridge connected, and SLI enabled, the screen starts to flash whenever a game or movie is played. With the SLI Bridge removed and SLI enabled, everything works fine again.

On contacting the service guys they were also at a loss at first after extensive testing with similar results and agreed to change the cards. But later they claimed that they have received a mail from NVidia that with 8600 and other 8 series cards, the SLI Bridge is not really necessary.

I wonder, if it is really so then why is it that Nvidia or POV provides a SLI connection point on the top of the card?

Please advice if the claim of the service people is really true.

Regards
Sherpa

[DMB2000uk]

Hello, welcome to the forums.

While SLI will indeed work without the bridge connector, you will probably end up with some sort of performance hit due to the reduced bandwidth available for the cards to talk across. However with your board supporting two full 16x lanes in SLI (as a pose to some other boards that can only do two 8x lanes in sli) and your cards not being that bandwidth intensive it might provide enough 'spare' bandwidth for them to communicate across and for you not to notice the difference.

So the service guys are more or less right in this case.

However if you do want to run SLI with the bridge, and it breaks all the time then you should probably see if you can get a replacement anyway.
(Just a quick check, would it be correct to assume that you have updated to the latest graphic drivers? And are you running xp or vista?)

Dan

[sherpa]

Hello, welcome to the forums.

While SLI will indeed work without the bridge connector, you will probably end up with some sort of performance hit due to the reduced bandwidth available for the cards to talk across. However with your board supporting two full 16x lanes in SLI (as a pose to some other boards that can only do two 8x lanes in sli) and your cards not being that bandwidth intensive it might provide enough 'spare' bandwidth for them to communicate across and for you not to notice the difference.

So the service guys are more or less right in this case.

However if you do want to run SLI with the bridge, and it breaks all the time then you should probably see if you can get a replacement anyway.
(Just a quick check, would it be correct to assume that you have updated to the latest graphic drivers? And are you running xp or vista?)

Dan

Hi Dan,

Thank you for answering.
Well, I do have the latest version of driver for the cards. I run Vista Business Edition (32Bit).
The Service guys however found the same problem with Win XP Pro + SP2 + latest drivers on the same mobo with my cards and then with two fresh 8600GT cards of same make. Their version is - the word SLI Ready signifies that no seperate SLI Bridge is reqd. as the cards are already "SLI Ready"!
Do You agree?

Regards,
Sherpa

[DMB2000uk]

7 series cards were SLI ready, but they still required bridges. So I disagree with that wording.

Dan

[Major_A]

Have you tried this?
http://downloads.guru3d.com/download.php?det=1680
Or the handful of other Vista/nVidia hotfixes?

[daniil]

I got same problem i use XP32 and XP64 , is there any fix for those?

[ibleet]

SLI ready cards can run in SLI mode without the bridge but there will be a definite drop in performance.

If windows detects an SLI configuration without a bridge present, a pop up window will alert you that performance will be better if a bridge is installed.

So, they are only telling you half the truth.

[Majki Majk]

Hello there!

I'm also super new to this forum and I will also project my problem from the start on. The non bridged SLI option is preatty interesting. I will try it out as soon as I get back from home. Here goes...

The following quote is a direct copy/paste of a letter I wrote to GIGABYTE support.

Welcome.

The problem I'm having with this motherboard is the SLI mode, or rather the lack of it. Here's a quote from the motherboard original package: "SLI: Dramatically scales graphics and gaming performance by allowing two graphics cards to operate in parallel and share the work load". Let's start form that. Here's the first qestion: in SLI mode, does the 2nd PCI-E x16 port slows down to 8x speed? Is it a normal thing that the 2nd graphic card is shown working in PCI-E 8x? If yes, why is there no information about it on the package? I also found no information about the 2nd PCI-E slowdown in the motherboard manual.

I configure the SLI mode by using the "nVidia Control Panel". I select the SLI configuration section, and the select the "Enable SLI Mode" and select the appropiate monitor to show the image on (Asus VW192s). Names of the section can differ, as I'm translating the names from polish right now (I have a polish operating system). Then the system needs to reboot. By enabling the SLI mode I have the option to configure the SLI rendering mode in the nVidia Control Panel. There I can select the "One GPU unit" mode, and also the "Splitframe mode", "Exchangeframe mode 1" and "Exchangeframe mode 2".

Time for some pure numbers.

3DMark2006 Results.

SLI mode enabled. Single GPU Mode set.

SM 2.0 - 3929, HDR/SM 3.0 - 4677

ONE Graphic card in system only results. (NON SLI)

SM 2.0 - 3912, HDR/SM 3.0 - 4679

Both of those results are very close to the same results in the following review:

http://www.hothardware.com/Articles/Gig ... HP/?page=3

Fine so far...

Back to SLI mode. Changing the SLI mode to "Splitframe mode" or "Exchangeframe mode 1" HALVES the FPS count on the 3DMark2006 benchmark!! I didn't even bother to end the tests. Selecting the "Exchangeframe mode 2" is actually SLOWER then the "Single GPU Mode". The SM 3.0 score is lower by around 400 or so points.

The same can be seen in a SLI certifided game "EVE Online (http://www.eve-online.com/).

Results for EVE Online bechmarking using FRAPS: (all mesurements taken in the same spot, with the same graphic setup of the game)

Single graphic card in system - 280 FPS.
SLI mode in "Single GPU Mode" - 267-270 FPS (so baisiclly the same as above, so far so good).
SLI mode in "Splitframe mode" - a graphical glitch appears in the middle of the screen, the game runs but a line shows up every few seconds in the middle of the screen. Splitframe mode - go figure...
SLI mode in "Exchangeframe mode 1" - 235 FPS.
SLI mode in "Exchangeframe mode 2" - 236 FPS.

Back to the 3DMark2006 results. Check the linked graphic card review once again. See the 5572 HDR/SM 3.0 score for SLI mode? I will never reach this result on my rig. Why is that? The single GPU results are matching but I can't by any way reach the SLI result, and I should, as the SM tests are GPU dependand only.

As You can see, the actual SLI mode are ALWAYS slower then one graphic card in system or SLI in "Single GPU Mode" mode. Why is that? Where is the "dramatically scaled graphics and gaming performance"?? Is the PCI-E x8 speed on the second GPU unit correct? Shouldn't it run in x16 speed. Even if, why does the SLI mode actually SLOW DOWN the preformacne of the PC. Please explain this to me, because something is defenetyl fishy here...

Regards,
*******.

P.S. Ok, today (03/26/2008) i found a review with the following table in it:

http://pclab.pl/zdjecia/artykuly/khedro ... nap329.jpg

According to the table, the motherboard works in 1x16x - 1x8x mode. So this is clear. But why is there NO performance boost in SLI certified applications like 3DMark2006 and EVE Online??!!


-------------------------------------------------------------------------------
Motherboard : GA-M57SLI-S4(rev. 2.0)
--------------------------
Motherboard Rev.: 2.0
BIOS : FG
SN: **********
-------------------------------------------------------------------------------
Graphic card model : GIGABYTE Model : GV-NX88T512HP REV.1.0
Processor : AMD Model : Athlon X2 4800+ Prędkość : 2GHz
OS : Win XP Service Pack : 2
RAM : Geil Black Dragon Typ : DDRII
RAM size : 2 x 1GB Prędkość : 800
Powerhouse : 650 W

I know it's long but it describes the problem I'm having preatty well. Thanx for any feedback. Read the P.S. part at the end of the GIGABYTE letter, as it updates the actual letter.

[Zertz]

SLI depends heavily on game developpers to code for it, performance gains can vary from none to about 70% in some rare occasions.

Don't worry about PCI-E 8x, it won't really slow you down, especially on a 8600GT.