here the thing that has been heard manytimes

3dfx Sli = NVidia SLI or 3dfx SLI = ATI's CrossFire
which isn't true or is it"

3dfx SLI
nvidia SLI
ATi Cross Fire.

if there is a difference can some body explain for all three types of sollution and which sollution is the best qua technollogy?

Cheers,

Ben Kenobi.

In short wrap-up :

3dfx (Voodoo2/Voodoo5-5500) SLI :
One GPU does the odd lines, the other the even lines.

3dfx Voodoo5-6000 SLI :
GPU1 does line 1,5,9 etc.
GPU2 does line 2,6,10 etc.
GPU3 does line 3,7,11 etc.
GPU4 does line 4,8,12 etc.

http://www.it.com.cn/f/diy/051/6/voodoosli.jpg

XGI :
AFR (I think)

ATI :
AFR, Scissor and Supertiling
http://www.rage3d.de/img/artikel/ati/crossfire/render_modi_uebersicht.jpg

NVidia :
Scissor (but dynamically balanced)

so NV SLI is more like Split Frame Rendering each card does half of the screen just as the idea Card A does top of the screen and Card B the bottom part.

hmm okay and 3dfx is indeed Scan Line Interleave idea hehe so a 5000 and a 5500 would work the same as a voodoo2 Sli set right? VSA-100 A does the even lines and VSA-2 does the unevenones so indeed more like NV's idea both chips do half of the work and with Sli you get one big thing.

But Ati is more complicated so many ways, I only thought that ATi only used one way and no so many togeather, Tile Scaling or something that looks very wierd, I suppose that technology is very new right?

I am looking foreward to ATI's upcomming R580 in Cross Fire unless ATi is gonna use thier MAXX technology again :)

BTW S3 uses a Multi GPU technology as well it's called Multi Chrome hehe also read that on thier front page some time ago :)
http://www.s3graphics.com/en/pressroom/pressrelease/2005/s3gpr051103chrome_s20Series.jsp

MultiChrome™ - Chrome S27 introduces S3 Graphics MultiChrome, an open-platform and cable free multi-graphics acceleration technology. MultiChrome will enable two or more Chrome S27 cards or GPUs to operate together to provide additional game acceleration on any motherboard with suitable PCIe slots, and its completely open, non-propriety demonstrated support on multiple vendor chipset solutions is another industry first for the Chrome S27 product.

here 2 S3 Chrome S27 Prototypes :P  in Multi Chrome mode on a test rig :)
http://tweakers.net/ext/i.dsp/1131189207.jpg

Well, the balanced Rendering of the NVidia type splits the Screen in half based on rendering load (e.g. if the top part of the Image is making for only 10% of the total rendering load, it should extend towards the bottom of the screen, while the 2nd GPU concentrates on getting the more heavy stuff rendered within its smaller piece)

I didn't mention S3 because (almost like XGI) are more or less dead like a doornail. Their time-to-market is generations behind by now & getting worse, and their cards almost nowhere seen outside the Asian markets.

IMHO all modern SLI/Crossfire solutions are of very limited use, they're very expensive, very power hungry and in the end, very loud with most reference Cooling designs. The way I see it, this SLI was just a result of the never-ending hunt for benchmark crowns.

What drives the market are solid performing single cards, at a good compromise between cost/performance, power consumption and noise level.

so 3dfx SLI was the only SLI that was really worth the money because in every app there was a signifficant boost of speed :) anyways the Voodoo5 6000 AGP did show me that compared to the Voodoo5 5500 AGP and PCI hehe :)

..basically,3dfx SLI was so good because games werent so complicated back then,splitting the screen to odd&even lines worked perfectly.but new games are much more complicated,and many of those nice effects simply dont work with certain multi-gpu modes.thats the reason why you can choose from up to three rendering modes.example: AFR is fast as hell,but totally incompatible with everything that uses post-process effects.scissors is compatible with everything,but its not very fast and gets stupid sometimes (even slowing things down).supertiling is fast,but doesnt work under opengl (right? not 100%  sure on this).shortly said,modern SLI systems suck :P

Hi,

I'll throw in some more info. By default each chip in SLI had 32 lines to render. Chip 0 would do 0 to 31, chip 1 wold do 32 to 63 etc.. That was in the fast mode. SLI band height could be changed in the registry.

In 4X FSAA each chip was responsible for entire screen with a different AA offset. The result was added and divided by 4.

The front end (PCI) was also implemented so the chips looked like a single chip to the driver. No command streem copy was necessary to each chip. All 4 chips would be read only if synchronization was necessary.

Visible protion of SLI was allowed to be rendered in bands, but off screen all the chips would render the same image. That is in the case if the image would be used as a texture in visible image. This way you do not have to move data between the chips.

Same texture was coppied to all chips.

This appears to be wastefull, but the final goal was achieved. The application did not have to do anything special to support SLI. You just turn it on in the control panel and enjoy.

wrote on 21.01.06 at 16:50:21:

..shortly said,modern SLI systems suck :P

that is your opinion, but it's still the fastest thing around. period, it does not suck other wise it wouldn't sell that good and perform that well D'oh  ::) ::)

Performance won't always scale, and determining which SLI mode (AFR - Alternate Frame Rendering or SFR - Split Frame Rendering) is correct could take some trial and error,

I thought you liked AFR so why not SLI ;) it does use it by the looks of it...

but SLI is easily enabled for any application with a few clicks of the mouse.

like Hank said just by click of the mouse SLI can be enabled or disabled ;)

Plus, some developers have started designing games that enable SLI 'out of the box' that require no NVIDIA profile at all.

which makes it even more effective for games that do support it

I got this info from a trustfull hardware site:
http://www.hothardware.com/viewarticle.aspx

and sorry ps47 but you sound a little Anti Nvidia , that does not mean thier technology is the worst they still have the best technology the benchmarks don't lie ...

ATi is gonna PWN them with thier new card I do think, but then actually NV and ATI are just though'n the mud at each other. at the Moment nVidia still holds the first place with Multoi GPU technology aka Scalable Link Interface dead simple there .

I think ATi is behind Nvidia is going to lead next gen :p

yeah.click here for 100% PWNage.

but I still think modern SLI is not the right path (of a true jedi,if you want) http://forum.3dfx.cz/images/smiles/icon_tongue.gif
;)

Sorry ATI has lost this round- The ATI solution is clumsy and in majority of cases takes a beating.

Yep, agree, performance-wise NVidia is a tad ahead (although only due to the almost paper-launched 7800GTX-512, baring in mind the X1600/1800 weren't available for ~2 months after launch as well).

But honestly, I couldn't care less, the tide will be turned with the upcoming X1900... some time later NVidia will release their faster Card... then ATI... then NVidia etc. etc.. and the cycle continues.
(and the 'normal' cards get cheaper, which is good ;D )

yeps I totally agree, BTW there are benchmarks of ATI's X1900XT 512MB v's nVidia's old 7800GTX 256MB , the ATi wins rather obvious agianst a 256MB version rumours are that it would loose against the 512MB version of the 7800 GTX that card also runs alot faster thatn it's 256MB version so even the X1900XT is a bad performer, it's because it only has 16 pipes that is the main bottleneck.

anyways driver updates might save it or it might not :-/
http://www.dailytech.com/article.aspx?newsid=310

I call it a bad test the fastest ATI versus the slowest NV 7800GTX card, I rather see a test of the Fastest V'S the fastest lol ATi has lost it again it's not even 25% faster than NV's 256Meg 7800GTX, that card is old compaired to the new one, ATi still has a big problem, they have to get thier X1900XT on the market and have to improve the drivers, they have to prepare thier Crossfire model also well to me they haven't made a great progress at all.

http://img76.imageshack.us/img76/3291/x1900xt512vs7800gtx2569pr.th.jpg

let's hope that ATi will give the X1900XTX model 48 pipes as 48 vertex units that should do the trick I'm think's ;D

Then it would be like the Radeon 9700 Pro was back in 2002 ;)

ATi's CrossFire is good but it still needs to be patched up, I am hoping that ATi will get better with thier R600 let's hope that that will change the world again. it's time they started to design a new way of Multi GPU technology which would give more effectiveness also, thier CrossFire is actually a Failed project sad to say., so maybe they should start useing the Scan Line Interleave way the best way imho :)

It's interesting to me that none of the hardware sites that got their hands on an X1900 sample had a 7800 GTX 512 to compare to.  Your graph was the third I've seen comparing the X1900XT to the considerably less powerful 7800 GTX (256MB).

I smell a conspiracy.

;D

oh well it's just a graph lol I'm hoping for a change in CrossFire technology,and I'm sure that ATi Technologies is quite aware of that, that there are things that have to be patched on the things that need more support , stabillity and speed in the apps of today and tomorrow.

ATi has come quite far since the demise of 3dfx, and I'm hoping they will stay longer than today, so I really hope that thier CrossFire will be fixed sooner this year, because every delay causes ATi to be left behind

I must say that ATi has a far better image quallity than nVidia cards, which is a great advantage is most cases, ATi als has the performance crown with thier great X1900XTX also :) man that card has lot's of sweetness in it.

a friend of mine has the X1900XT also a nice thing to have in my hands 2 weeks back :D, within 3 weeks I will make some nice pics of the ATi X850 XT PE AGP and the X1900XT PCI-E as combo shots :)