64 Bit SLI

[Ranger56]

i found a motherboard(939) with SLI. im probably going to buy it but i just had a very important question. lets say i buy two 6600 GT supporting SLI. will i need to instal 1 driver for both vid. cards and a driver for the SLI? because i dont really understand this. plus do they have 64-bit SLI out yet?

[Augie64]

Yes you would only need one driver since its the same card. that would be the current Nvidia driver.

Basicly what it is is using 2 video cards to proccess 1 output. the cards are installed and a jumper connects the two cards.
So card one renders the first line, card 2 does the second. they alternate.
I havent set up an sli system yet so im not too sure exactly how you do all the settings. im assuming its mostly bios settings you have to change after you install the 2 cards. This will deffinatly be supported under 64 bit systems. But like all new technology (ok its not so new 3dfx came up with it in 96) things dont always go as planned.


http://www.anandtech.com/cpuchipsets...spx?i=2248&p=3

[Ranger56]

augie! thanks alot! that link helped alot! i was going to waste a whole lot of money buying 2 6800 ultra but i see 2 6800GT had a bitter increase in performance so now i can save some money. but i just would like ot know where i can get the cable that connects the 2 video cards together, does it come free with motherboard or the video card? or do i have to buy it separetly? again Thanks augie

[Ranger56]

i forgot one little question on that link u send me there was a picture labled "step 4" does this mean my screen will be divided in to two sections?
here is the link for the picture
http://www.anandtech.com/cpuchipsets...4/SLI_MOBO.jpg

[danrok]

I believe this current version of SLi splits the screen in half. One card handles the top and the other the lower half of the screen.

[danrok]

Actually, there's another mode where frames are alternated between the cards:
http://graphics.tomshardware.com/gra...rmance-01.html

[cadaveca]

SLi allows either frame swapping, or half-screen. It really all depends on which game it is...and they need to be supported by the driver. I am sure that the driver support will expand greatly with updates, but they only about 25 or so games currently supported.


Any SLi motherboard comes with the PCB inter-connect for connecting the 2 cards. Also be aware that you cannot connect just any 2 Nvidia pci-e cards. They must be of the same model, and bios as well. Oh, and they need to have the SLi pcb cutout. Make sure to get a robust power supply as well, and definately don't spare cash on the psu if you plan to overclock.

[GrahamGarside]

will boards be allowing you to use independent cards instead of SLI? say if you want two cards showing seperate displays? this wa the biggest shortcoming of agp in that there could only be one instaled card

[cadaveca]

yes, you can connect 4 LCD's, if you like. And then you can switch to SLi mode (requires a reboot) and only use one display...and still have all four connected. It's quite nice, actually. 4-21 inch lcds......


I'd wait for the secodn revision of the chipset before making any SLi purchases...and at least 2nd revisions of the mobo's. But i guess someone has to take the plunge to get the bugs worked out right!

[GrahamGarside]

back before cards had 2 displays I always wanted 2 agp slots because the pci card I used wasn't very quick and even now I wouldn't mind another display so I can have 2 monitors and a tv display, though I've heard ATI IGP's allow this if you get an ati add-in card (one of the onboard displays still works)
my next board/cpu/vid card upgrade are a long way off just plumped out 200 big ones on a 6800 due on friday so if you don't hear from me you know what I'm up to

[Kaitain]

Originally Posted by cadaveca

SLi allows either frame swapping, or half-screen. It really all depends on which game it is...and they need to be supported by the driver. I am sure that the driver support will expand greatly with updates, but they only about 25 or so games currently supported.

SLI really shouldn't need designed-in game support for frame swapping to work. Look at it this way - where the game (or operating system) is concerned, there is only 1 display and 1 frame buffer to write to. This is actually the case, however many cards there are in parallel here.

In a 3D game, the graphics card is working on effectively 3 things: 1) a set of n translation matrices (forward and inverse) for each visible or nearly visible object in range to determine position, velocity and acceleration. 2) For each visible object, surface/texture mapping. 3) For each surface, the effect of lighting. If you allow that to set the first screen up takes maybe a millisecond longer in SLI than in a single chip system (to calculate the coordinates of all objects after a discrete time interval), then one GPU can work on all odd numbered frames entirely independently of the second GPU working on all even numbered frames. The image itself only actually comes together when all the components (coordinates, surface, T&L) are blended together in the frame buffer. As such, the game need not actually be aware that the hardware is splitting the work up between n processors.

What will be interesting is what happens for subsequent driver revisions - obviously the card with the monitor attached has to work harder, since it has to process the final picture. It will be interesting to see how the components of making a frame are broken up between the two cards to keep both at maximum capacity.

If games really do require support for SLI to be designed in, then this shows poor forethought on nVidia's part in how they represent the SLI to Windows.

[cadaveca]

No, you mis-understood...it has to be predetermined by the driver which mode it uses, as some game/rendering combos make for really crappy visuals....and for the splitscreen, because of v-sync, it can be a problem. Only a few games are supported for the split-screen mode...and it is not half-half...it's more like 60/40.

[Ranger56]

well power supply should be no problem for me since i am getting a 550w power supply. have u guys played old nintendo 64 two player games? u know how the screen is cut in half and first player has top and second has buttom. i just dont want a screen like that. i understand it now. when u have it in SLI mode one card takes care of the frames on the buttom half and another takes care of the top half. and where can i get a list of games that support SLI?

[GrahamGarside]

all games should benefit from SLI

[Ranger56]

ooh good! cuz when i run Hl2 just playing it is a pain in the ass with all the loading time and video lag.. this piece of **** PC! i hate it! 64 bit is the best my friend has athlon 64 3000 and his runs smoother and my video card is better.

[GrahamGarside]

what pc do you have? do you have an nvidia card and your friend an ati by any chance

[danrok]

Some guys have had to swap out the heat sink on one of their SLi cards just to get them to fit! There's quite a few potential stumbling blocks with SLi at the moment. So be prepared for hassle.

[Ranger56]

GrahamGarside i have a GeForce 5700Le and my friend has 5600. it might be because his is running on AGP 8 and mine is on AGP 4. and danrok i really quick question. im gana do water cooling so that should take away the problem with thing u said about not enough room. and as usual one more question remains. im going to have 2 6800GT PCIe Athlon 4000+ and 2 hard drives. since i am having water go to all of them to cool them down wouldnt the hardware that is last get hot water and not cool down? so would this formula good?
waterpump--->CPU--->vidcard--->vidcard--->harddrive--->harddrive--->radiator

[GrahamGarside]

the 5700LE is a heavily stripped down version of the 5700 card. It's quite likely that your friends 5600 is a full featured 5600 compared with your entry level 5700 and that is why it's outperforming you. though cpu speed does have an impact on HL2, with that level of graphics card it is more likely that they will be the limitting factor.
I also doubt running on agp 4X is it either, even though agp 8X is double the speed this probabally only accounts for a ~5% performance increase, just like pci-e makes very little differance over agp 8x inspite of it's increased bandwidth

[Ranger56]

well i sold him the 5600 and i can see why the LE was the same price as the 5600 when i bought the 5600. i have to say it was a good card, plus it could handle overclocking unlike this crappy piece of ****. anyways why dont they make video cards that use almost all of the bandwit instead of someone it. also how come PCIe cards are cheaper than AGP?