SLI and crossfire

[lodore]

Hello,
i know that crossfire is from ATI and links two graphics cards together.
i know that nvidia have a similar sort of system linking two or four graphics cards together called SLI.
now it seems that for SLI to work it needs a profile for the game. if it doesnt it defaults to one card while the other card stays idle.
or even worse if you have quad SLI and it doesnt have a profile then it still defaults to one card meaning your expensive graphics cards are being wasted since your only using one.
but on the ATI site it says crossfire works with all your games.
so can crossfire really use crossfire for all games?
im trying to persuade my dad to get a new Pc for xmas.
i worked out that atm two ATI Radeon™ HD 2900 512mb cards. with crossfire motherboard,quad core 2.4intel core duo processer and 2gb of ram is around £1400.
by xmas that will be less than £1000 reallly easy.
which will mean by xmas my family will be able to afford the spec above.
thanks in advance
lodore

[BUFF]

but on the ATI site it says crossfire works with all your games.
so can crossfire really use crossfire for all games?

No, iirc SLI tends to work for more games than CF.

However, do you need either?
Unless you are running somehing like 1900x1080 or better than a single top-end card is more than adequate.

[lodore]

thanks for your reply Buff.
yoru right i dont really need more than one card.
512mb single card is more than enough for my 19inch Dell
at 1280X1024
my next pc will just be the baseunit since ive already got a decent keyboard and mouse and my dell monitor.
lodore

[Lucio]

No no, it's a 768MB card that you need, none of this ATi rubbish.

Unless the word budget enters your frame of reference

Which it shouldn't

[lodore]

the 768mb nvidia 8800 is very decent.
i know by xmas it will a whole new kettle of fish.
computers move so fast i will have to check closer to the time.
atm im just trying to work out what i coild get for the cash.
the budget it probaly around £1100
lodore

[ebgsm]

hi new here and about to build a pc i have decided (much to the amusement of others) to choose 2 x 1Gb 2900 GDDR4 in crossfire i have however also been to ATI's site where they have a page on crossfire and physics no.1 does anyone know if it is possible to use 3 x 1Gb 2900 in this way and secondly does anybody know of a mobo that would support this? P.s. not sure if i've posted this in the right section - sorry if i haven't

[MadduckUK]

sorry ebgsm, i wrote a really lengthy reply to this, but i was laughing too much at the situation you find yourself in to post it

[ebgsm]

lol
new here not new to pc's
and i am trying to see the point in ati doing or rather preaching of a 2+1 set up if there is no motherboard out there to support it, i know and have looked at quite a few mobo's but cannot search through them all but as far as i am aware there are none, but thanks for the none lengthy reply,

[MadduckUK]

it was mainly about charging £4.79(exc vat) per word for advice if youv got that kind of money to throw around.. you wouldn't have been interested

[ebgsm]

sry lol had a long day with mental kids
do you know if a 3 pci-e at x 16 bandwidth will be available, i can't afford to build another pc or
change it once it's built. but don't want nvidia either so if anyone has any info it would
be great - failing that i'm gonna have to make do with 2 cards

[MadduckUK]

its this attitude to it thats confusing, i dont know what you mean by "make do" with 2 cards.. by the time the third card comes into play from a performance perspective (speculation, watch out!) the lot of them will have been surpassed by some DX11 card that can do something your ageing x2900's will be physically incapable of, no matter how fast they are in a 3. and while they may still be king of 3dmark08 there 3dmark09 score will be challenged or surpassed by one high end amd3900xtx/nvidia9900gtx.

better to put away money to upgrade later and only get what you neeed than go overkill now, which is what you would be doing.

[ebgsm]

what i mean't by make do is i would have loved to find a way to make three work, but i am slowly realising that this may not and possibly will not be possible. 2 cards i know won't exactly be slow and yes 3 is probably overkill, but just for once i would have liked a way to make the silly overkill computer work.
like i said i can't afford to start swopping mobo's and gpu's later to get the required result but it's looking like i will be forced into a standard crossfire setup and possibly won't be happy with the end product. Lol i am fully aware of the overkill and also fully aware that in 6 months or less we are looking at possibly the R700 and definatly the R650 but wouldn't you agree that for 1-2 months the crown of the silly overkill computer that is lightening fast would be nice whilst it lasted if it were yours