Sign in with
Sign up | Sign in
Your question

SLi Setup, wrong information.

Last response: in Graphics & Displays
Share
August 30, 2012 7:27:39 PM

Hi all,

only the other day i bought an Nvidia GTX 285 to pair it with my other one just for a few more frames, as it was cheaper than a brand new card..

so the problem is, i have now got an EVGA GTX 285 2GB, also my original ASUS GTX 285 1GB.

i was told this will work in SLi as the memory is the only difference, but i cant get it to work. So now im guessing i was told wrong..

should these two cards work or not?

iv tried everything to get them working but no dice.

system specs are,

i5 2500k standard.
8GB Gskill mem
ASUS Maximus iv Gene-z/Gen3
700W OCZ mod ex PSU
Win7 64 Ultimate.
306.02 NVIDIA drivers. display+PhysX

i had a look around the forum but cannot find the definite answer..

thanks.
August 30, 2012 7:46:06 PM

Yeah I think someone told you wrong... pretty sure the cards need to have the same amount of vram to go into SLI. It's only clock speeds that don't really matter.

-edit- Looked into this a bit more and this is the official word from Nvidia's site:
Quote:
Can I mix and match graphics cards with different sizes of memory?

When purchasing a second graphics card, you should try to match the memory size so that you are ensured full value and performance from your purchase. However, while it is not recommended, NVIDIA does offer the flexibility to run graphics cards with different sized memory by using CoolBits. Using CoolBits (value set to 18), you can force both of the cards to use the lower of the two memory sizes and operate them together in SLI mode. When dissimilar memory sizes are enabled to work together using CoolBits, the effective memory size for each card becomes the smaller of the memory sizes.


Don't know what CoolBits is, but apparently you were told right - with some fiddling you should be able to get it to work.
a c 271 U Graphics card
August 30, 2012 7:50:23 PM

BigMack70 said:
Yeah I think someone told you wrong... pretty sure the cards need to have the same amount of vram to go into SLI. It's only clock speeds that don't really matter.

For the most part it will work but there have been a couple of exceptions over the years like the XFX 7800GTX's and 9800GTX/GTS250.
Related resources
August 30, 2012 7:51:27 PM

dammit! so now i have a null card.. bugger..

even if i sold them both i couldn't buy a new-ish card.. this sucks lol.
August 30, 2012 7:53:40 PM

Mousemonkey said:
No, I meant the opposite.


ah right ok, thanks :) 
August 30, 2012 7:54:02 PM

just seen the EDIT, so if i tried coolbits it might work..

ill get back to you guys, thanks for the help BigMack.

Mousemonkey, you mean only a handful have worked like this?
a c 271 U Graphics card
August 30, 2012 7:55:13 PM

skriller said:
Mousemonkey, you mean only a handful have worked like this?

No, I meant the opposite.
August 30, 2012 8:02:02 PM

Ok! i installed coolbits, which only enables extra features in NVCP, restarted and i got the popup my computer is SLi capable! woop! now to see if it works.

Thanks again guys! i thought i was gonna have to get rid of the new card..
a b U Graphics card
August 30, 2012 8:15:27 PM

you should dedicate your CPU to PhysX, instead of the 2nd card
a b U Graphics card
August 30, 2012 8:18:02 PM

Never ever sli/crossfire with different specs and model they should be identical in aspect everything vram, clock speed, etc.
a b U Graphics card
August 30, 2012 8:19:57 PM

dingo07 said:
you should dedicate your CPU to PhysX, instead of the 2nd card


PhysX runs far better on a video card than CPU.
a b U Graphics card
August 30, 2012 8:22:47 PM

xtreme5 said:
Never ever sli/crossfire with different specs and model they should be identical in aspect everything vram, clock speed, etc.


Nvidia themselves say that it can be done without much issue. They don't have to be the exact same cards.
August 30, 2012 8:36:35 PM

so should i continue to use both cards?

what about PHysX? CPU or GPU?
a c 271 U Graphics card
August 30, 2012 8:43:08 PM

skriller said:
so should i continue to use both cards?

what about PHysX? CPU or GPU?

Hell yeah! And leave PhysX on "Auto" sometimes the game may be coded for CPU, if you want to check then just enable the SLi and or PhysX indicators via the Nv control panel.
a b U Graphics card
August 30, 2012 8:46:04 PM

ahnilated said:
PhysX runs far better on a video card than CPU.

his processor is much better equipped at processing PhysX than that video card is
a c 216 U Graphics card
August 30, 2012 9:09:41 PM

dingo07 said:
his processor is much better equipped at processing PhysX than that video card is


Every review I've seen shows that a 260-270 is pretty optimal for Physx and anything beyond that doesn't usually do much. Set it to auto, it'll be best.

That isn't to say that he can use GPU accelerated PhysX in all games that offer it, as he doesn't have the fastest system, but he can always turn it off in game.
August 30, 2012 9:10:30 PM

guys dont argue lol... i didnt come here to start anything..

thanks for all your help though :D 
a c 271 U Graphics card
August 30, 2012 9:16:52 PM

dingo07 said:
his processor is much better equipped at processing PhysX than that video card is

That would depend on how PhysX is implemented in each particular game by the developers of that game.
a b U Graphics card
August 31, 2012 1:36:28 AM

Mousemonkey said:
That would depend on how PhysX is implemented in each particular game by the developers of that game.

True indeed
a c 216 U Graphics card
August 31, 2012 2:41:19 AM

dingo07 said:
That video comparison is laughable at best. Did you see that he has an i5-2500K? Here's the comparison between the proc in the video and the 2500K - worlds apart! Enough said...


You do realize that many games won't even let you use advanced PhysX settings without an Nvidia card to render it on (Dark Void as an example), while others are completely unplayable with advanced PhysX settings due to really bad performance (Sacred 2, Batman AA and AC). There are very few games with advanced options that are playable on a CPU, Metro 2033 is the only one I can think of.
August 31, 2012 2:45:56 AM

I can play Batman AC at 30fps average with maximum PhysX settings... and it's very playable if you just turn that down a notch or so.

PhysX is 10% awesomesauce and 90% green marketing koolaid.
a c 216 U Graphics card
August 31, 2012 2:51:37 AM

BigMack70 said:
I can play Batman AC at 30fps average with maximum PhysX settings... and it's very playable if you just turn that down a notch or so.

PhysX is 10% awesomesauce and 90% green marketing koolaid.


There are 3 settings of advanced PhysX on Batman AC and 30 FPS is not exactly what I'd call playable anyways. I'm not talking about the merits of PhysX, only that many games, it is not playable if not on a GPU, with some exceptions.
a b U Graphics card
August 31, 2012 4:03:46 AM

bystander said:
You do realize that many games won't even let you use advanced PhysX settings without an Nvidia card to render it on (Dark Void as an example), while others are completely unplayable with advanced PhysX settings due to really bad performance (Sacred 2, Batman AA and AC). There are very few games with advanced options that are playable on a CPU, Metro 2033 is the only one I can think of.

Yes, I do realize...

Look, I'm not trying to make a fuss, all I'm saying is - what I said before, that was an extremely poor example of a comparison to what's available today and to what the OP has
August 31, 2012 1:09:30 PM

i started an argument... sorry guys lol.
a b U Graphics card
August 31, 2012 4:03:38 PM

skriller said:
i started an argument... sorry guys lol.


You mean you started a discussion :) 

Either way, video cards do physics better than a CPU will. There are tons of tests out there that you can do to test your system out if you like.

If you really like the eye candy it is fun to see. After a while I found I have set my system so I keep at least 50 fps and then adjust the eye candy accordingly.
!