OK, so we know that we have to run the same card in SLI

R

RooK

[H]ard|Gawd
Joined
Aug 19, 2001
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for it to work...

(this is right, right?)

I've got an 8800GTS 320 meg card... well... with the 640's coming down so much in price, SLI might be in the works...

but wait... different memory amounts...

I was thinking about something...

What about flashing the 320 version with a 640 bios? Now, I know the possibilities here - a game would think that it had 1280 megs of video ram to work with and start dumping it on there...

BUT, the question is, is HOW does a game dump info on to a vid card? Does it start with one? In that case, if you knew that the higher card in slot X would be filled before the lower card in the other slot, then you would have actually 960 megs to work with, and *theoritically* should not get any games crashing out on you until you hit that mark.

I'm just being creative here - a simple "no that won't work" is fine, but a more detailed "that won't work because" would be even nicer.

Danke!
 
AFAIK you don't get 2x memory when doing SLI.. so you would downgrade the 640 -> 320.
 
yeah, if you got yourself an EVGA card you could have just stepped up instead.
 
RussianHAXOR said:
yeah, if you got yourself an EVGA card you could have just stepped up instead.
Click to expand...

I did get an EVGA

and after reading the review about SLI on 640's vs 320's, i'm not too sad about it....

I guess my original thought probably needs someone smarter than me to force it to pull it off
 
RogueTrip said:
they have to be the same core and memory.
Click to expand...

which is why i said flash the bios of the 320 to a 640...

then the drivers wouldn't know the difference (as long as you had two EVGA's for example) since the cards are exactly the same minus 320 megs of ram
 
I forgot about this from nvidia SLI FAQ

Can I mix and match graphics cards with different sizes of memory?
While it is not recommended, NVIDIA does offer this flexibility using Coolbits. 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. For example, if your first card is a GeForce 6600 GT with 128MB of memory, you should purchase a second GeForce 6600 GT with 128MB of memory. However, using Coolbits (value set to 18), you can force both of the cards to use the lower of the two memory sizes and operate 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 two memory sizes. Instructions to enable this feature can be found
Click to expand...

So it might be able to be done without the bios
 
hey RooK, the thing is this... even if you DO get them to run in SLI:

you won't get 640+640 = 1280MB -- that's obvious because you have a 320 and 640
you won't get 320+640 = 960MB
you won't get 320+320 = 640MB

you will actually get ONLY the lesser of the two cards, in this case 320MB.

Yeah that's right, even if you had 960MB of ram on your video cards, they will effectively use only 320MB. So, if you want to do SLI, just get another 320 or sell yours and get 2 640s.
 
KenDawg said:
hey RooK, the thing is this... even if you DO get them to run in SLI:

you won't get 640+640 = 1280MB -- that's obvious because you have a 320 and 640
you won't get 320+640 = 960MB
you won't get 320+320 = 640MB

you will actually get ONLY the lesser of the two cards, in this case 320MB.

Yeah that's right, even if you had 960MB of ram on your video cards, they will effectively use only 320MB. So, if you want to do SLI, just get another 320 or sell yours and get 2 640s.
Click to expand...

but if he flashes the bios of the 320 to think its a 640, then uses the 640 as the card with the memory, it should work out... unless there is some unforseen obstacle.
 
KenDawg said:
hey RooK, the thing is this... even if you DO get them to run in SLI:

you won't get 640+640 = 1280MB -- that's obvious because you have a 320 and 640
you won't get 320+640 = 960MB
you won't get 320+320 = 640MB

you will actually get ONLY the lesser of the two cards, in this case 320MB.

Yeah that's right, even if you had 960MB of ram on your video cards, they will effectively use only 320MB. So, if you want to do SLI, just get another 320 or sell yours and get 2 640s.
Click to expand...

Not really that big of a deal. 320's enough for most things, especially with the power of SLI. I bet downflashing the 640 would work... It'd just lose track of the other 320mb.
 
Arcygenical said:
Not really that big of a deal. 320's enough for most things, especially with the power of SLI.
Click to expand...

nope, it's not a big deal. i'm just warning him not to spend extra on the 640 when it'll be exactly the same speed as if he gets a 320 :)
 
basically i'm wondering how info is stored on there...

since everyone is saying it only uses 320 or 640, then which card is used for the memory storage?

if only one card is used, then it would make sense to save some cash and get one of each, and then flash the bios of the 320 to 640 IF YOU KNEW that the REAL 640 was going to be the only one to have its memory addressed.

I just need to speak to an engineer for this one :p
 
RooK, BOTH cards use the same information in their own memory. it goes like this:

320 MB of info ----> gpu1

same 320 MB of info ----> gpu2

since it's the same data and they both work with it, the cards are technically using 640 MB, but it's the same stuff twice.
 
exactly, SLI dumps the same data in both cards

so effectively, even if you have 2 320 cards in SLI, your system can only store 320 mb of graphics data, because it stores the same data twice (im guessing with some very very very tricksy drivers NV might be able to pull off some sort of partial overlap scenario which would allow for only partial memory cohesion, but this could come around and bite you in the ass in unforseen scenarios in the graphical situation)

so a 320 and 640 GTS in SLI --> 320 mb of locally stored data

how long ago did you get the 320? eVGAs step up program is good for 3 months, you could just wait and see till the 14th and maybe go for a 8800U instead of SLI
 
DrFreeze said:
exactly, SLI dumps the same data in both cards

so effectively, even if you have 2 320 cards in SLI, your system can only store 320 mb of graphics data, because it stores the same data twice (im guessing with some very very very tricksy drivers NV might be able to pull off some sort of partial overlap scenario which would allow for only partial memory cohesion, but this could come around and bite you in the ass in unforseen scenarios in the graphical situation)

so a 320 and 640 GTS in SLI --> 320 mb of locally stored data

how long ago did you get the 320? eVGAs step up program is good for 3 months, you could just wait and see till the 14th and maybe go for a 8800U instead of SLI
Click to expand...

word... you and kendawg provided some great stuff...

All I can say is that I wish I knew how crysis would run on my current rig right now... and then how it would run on my rig plus another 8800GTS 320 in SLi...

because - right now, i love my 20.1" widescreen, and while I would love to have something bigger, I can't really justify it to myself - a nicer guitar would bring me better joy... actually, the money in the bank would as well...

so either I guess i'm becoming an old man, or I appriciate money in the bank more than I used to...

bleh...

i just want to make something clear to myself while i'm at it... HOW MANY GAMES HAVE I GONE APE SHIT BANANAS OVER...

1 - MegaTF (quake1)
2 - Counterstrike (HL1, uhh.. in the beginning... i stopped playing around '03)
3 - Natural Selection (HL mod... it rules... or at least did.. haven't played it since...
4 - BF2

and thats it...

I mean... i'm not including things like starcraft becuase of prevelant cheating... also, i'm not including really cool single player games like FEAR... To me, a game is a game if the multiplayer blows me away and keeps me coming for more...

And the sad thing on that note is that I doubt crysis will have very many good mods for some reason...

I bet they all will be just outrageous mods... nothing close to "sci-fi" like natural selection is....

eh... i could go on forever and I type fast so i'll stop now.
 
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