Can we use two GFX cards of diff. brands???

what happens if i use GF106-based GeForce GTS 450 on one PCI slot...and any other ATI 1GB card on the other slot...???

Any problems occur...or is it better to SLi By using two NV's or crossfire two ATi's??????

Thank you...

^^No u cant use 2 different manufactures card

For SLI you need two exactly same cards from nVidia but you can have them from different brands like an Asus GTX 460 and XFX GTX 460.

For Crossfire, you need two AMD cards of same series, not exactly the same card. For example you can Crossfire a HD 6870 with a HD 6850/HD 6870 or a HD 6970 with a HD 6950.

what gives more throughput?? Sli or cf?

bhushan05d251 said:
what gives more throughput?? Sli or cf?

As of now, CF scaling and performance is better than SLI.

rahulbalmuri said:
what happens if i use GF106-based GeForce GTS 450 on one PCI slot...and any other ATI 1GB card on the other slot...???

Any problems occur...or is it better to SLi By using two NV's or crossfire two ATi's??????

Thank you...

IMO You can use both of them, without any issues, if the Nvidia Card is configured as Physx card & AMD's as Primary Card. But for SLI or CF, you need two identical Nvidia Cards or AMD Cards respectively....

^^
Will not run, unless you use hacked drivers. The nVidia PhysX card will not work cause the driver "tells" it not to work, if the primary accelerator is non-nVidia.

there is a company Lucid, that has a solution
Lucidlogix with the multi-GPU solution
Lucid Logix HYDRA tech brings together any GPUs for powerful matrimony -- Engadget

why didnt anyone think of doing this before?

i really wish it becomes mainstream.

Gaurav Bhattacharjee said:
As of now, CF scaling and performance is better than SLI.

Sli was always better than cf with the exception of this generation gpu's. Cf is scaling very well now and is par with sli and sometimes even surpasses it.

This generation, amd gpu's scale better because of the extra framebuffer their cards come with relative to their nvidia counterparts.

Let me give an example:

We all know that gtx 570 is a stronger gpu than 6950. Its ahead in almost all benchmarks. But at higher resolutions the gap closes pretty much. In their respective multi gpu setups, 6950 cf performs and scales better than 570 sli because the former comes loaded with 2gb vram while the latter only has 1.25gb.

So the 570 is held back at higher resolutions and cannot scale as good as a 6950 duo. Nvidia must take this matter seriously on its future gpu's.

Some board makers are taking the initiative and making custom designs with extra vram. The zotac and palit gtx 580's come with 3gb vram instead of 1.5gb on the reference design.

If we compare 580sli with 6970cf, the 3gb version will increase the performance gap between 580 and 6970 at higher resolutions and allow the gpu to perform more efficiently without sacrificing fps.

How much performance boost will be there if crossfire with HD5770???

^^ You will get 85-90% boost.

^^ok...& it will be comparable to which single GPU card???

Zangetsu said:
How much performance boost will be there if crossfire with HD5770???

vickybat said:
^^ You will get 85-90% boost.

Zangetsu said:
^^ok...& it will be comparable to which single GPU card???

@Zangetsu: you can compare the performance of two 5770 with 5870, but not with 6870.

@ Vickybat : With the price of two 5770 [7k * 2], OP can get a single 6870 [12k], which beats 5770 CF from top to bottom & can save some cash on getting a new PSU too.

^^ 5870 is faster than 6870 but the former has less tesselation performance. But yes its wise to sell off the existing 5770 and get a new powerful card. A 6870 @ 12k is a good choice and op will see noticiable performance increment.

i think OP is using his 4870x2

vickybat said:
^^ You will get 85-90% boost.

You sure the scaling is that much..?

Vicky, even I'm not sure with 85-90% performance in case of a HD 5XXX series card crossfire. Actually AMD 6XXX series cards offer better Crossfire scaling than their 5XXX series brother. 5XXX series scaling is not that much except in few games.

vickybat said:
Sli was always better than cf with the exception of this generation gpu's. Cf is scaling very well now and is par with sli and sometimes even surpasses it.

GTX 400 series especially GTX 460 had better SLI scaling. Before that it was about the same.

In the current generation CrossfireX scaling isn't surpassing SLI "sometimes", rather most of the times.

HD 6950 1GB CF is better than GTX 560 1GB SLI by 5-10% and this was already argued to death in the GTX 560 thread.

HD 6950 2GB CF is surpassing GTX 570 SLI at lower resolutions too (not only at high). Again down to superior scaling for whatsoever reasons.

vickybat said:
^^ You will get 85-90% boost.

More like 60-70% on the average and further more depending upon the game. Benchmark sites only choose cherry picked games which perhaps they think would offer good scaling and yet they come across scaling problems.

I second the link that Doomgiver posted. Lucid Logic is supposed to enable cross GPU combinations.

the only issue is that there are very few motherboards which carry it. I also think that if it starts to sell well, then Nvidia and AMD will block it on driver levels, because it threatens their business model.

So to answer OP's question, it is possible theoretically, but practically limited.

well, i think it'll just take 2-3 instruction cycles per api call.
if you have a good enough rig, its not going to be noticible

rchi84 said:
I second the link that Doomgiver posted. Lucid Logic is supposed to enable cross GPU combinations.

the only issue is that there are very few motherboards which carry it. I also think that if it starts to sell well, then Nvidia and AMD will block it on driver levels, because it threatens their business model.

So to answer OP's question, it is possible theoretically, but practically limited.

Lucid Hydra chipset is not new, it is in the market for last couple of years. But the scaling with Lucid Logic when GPU from two different chipset makers are used is far inferior than the scaling of either SLI or Crossfire. Also a lot of games don't support it for multi-gpu profile

doomgiver said:
well, i think it'll just take 2-3 instruction cycles per api call.
if you have a good enough rig, its not going to be noticible

What are you trying to say here, not clear to me.

Also for Lucid Hydra to work the drivers have to be released so it can be enabled in each game. And these drivers are made by the Lucid Hydra team. So today when Crysis 2 is released we can play it out of the box for nVidia/ATI. But will Lucid Hydra we will have to wait for the official driver for the game.

well, i meant that,
originally
gpu>driver>display
now
gpu>lucid>driver>display

is this ok?

well, i saw some mobo from msi support both nvidia+ati at same time.. it was advertised in chip magazine. not sure of which month...

doomgiver said:
well, i meant that,
originally
gpu>driver>display
now
gpu>lucid>driver>display

is this ok?

It is not that simple, just to plug in another API call in the middle.

A. The ATI/nVidia driver will not be there.
B. Between GPU -- driver -- display is the software layer.
C. As I explained each driver needs a game profile which Lucid has to make.
D. This unified driver should be able to realize hardware registers of both nVidia and ATI which of course are vastly different, and integrate with the host software.

asingh said:
It is not that simple, just to plug in another API call in the middle.

A. The ATI/nVidia driver will not be there.
B. Between GPU -- driver -- display is the software layer.
C. As I explained each driver needs a game profile which Lucid has to make.
D. This unified driver should be able to realize hardware registers of both nVidia and ATI which of course are vastly different, and integrate with the host software.

i think i should have made it like this:
display
-----------^v
rdriver <> lucid <> gdriver
-----------^v
respective card

but isnt the lucid driver taking over the job of calling to the kernel and physical devices?

the lucid intercepts calls from the drivers and shunts them to the respective cards. also, it'll have to calc how much load to give to each gfx so that frame rate remains maximum.

The lucid driver will be the GPU driver.

ico said:
In the current generation CrossfireX scaling isn't surpassing SLI "sometimes", rather most of the times.

Well that is because of insufficient framebuffer in nvidia cards relative to the gpu core. If you compare a 69702gb cf with a gtx 580 1.5gb sli, 6970CF comes very close and even surpasses the 580SLI at higher resolutions. But compare this with a 3gb gtx 580 sli. The results will be different and sli will scale equally good and keep its distance from a 69702gb cf.

ico said:
HD 6950 1GB CF is better than GTX 560 1GB SLI by 5-10% and this was already argued to death in the GTX 560 thread.

Yes this true for the stock 560. But oced 560's like msi twin frozr II and asus direct cu II top , when slied , scale equally good as a 6950 1gb cf and are on par with it. 69502gb cf beats oced 560 sli in most games and again we can account this due to the extra vram.

I had opened a thread named "multi gpu wars" in the graphics card section and it has a review by hardocps between msi 560 sli vs 69502gb cf vs 68701gb cf.

Check that out. Check 6950 1gb cf review HERE.

ico said:
HD 6950 2GB CF is surpassing GTX 570 SLI at lower resolutions too (not only at high). Again down to superior scaling for whatsoever reasons.

Well here, gtx 570 is hugely restricted by its paltry 1.25gb vram. Thus the 6950cfx leads here in most of the tests. Sli scales equally well but performace is somewhat down in these gpu's due to insufficient vram and most review sites say this.

dats a hell of discussion....awesome info guys...thanks a lot... clears all of my doubts..