Crossfire efficiency

hi,I have a question,when we use two cards as crossfire,can we sum their specifications,I mean their memories and shaders and....,with each other exactly??

and if we assume that the first card (the upper one) can work at 100% efficiency,how much efficiency does the second (the lower one) card have? 50%? 60%?...90%? or the second card can work at 100%???

my mainboard is p5k,intel p35 is its chipset,does chipset of mainboard have anything to do with crossfire efficiency?

please help me,it's very important for me.

Message edited by ethilen on 09-20-2009 at 12:25:41 AM

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Some (very very few) will show 100% scaling, most will show 50% or less, and a good amount may show around 60-70% increases.

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Reply to annisman

Depends on game, settings nad hardware used.

The resources of the cards do not get pooled, they are still the same cards. They usuallly do alterating frames.

It is best to have both pci-e slots at the same speed, I am unsure if your mobo supports that.

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Reply to strangestranger

I don't think your motherboard supports Crossfire.

And regarding effieciency.. if two cards are in Corssfire then the load will be divided equally. Typical effieciency is in between 50-70% for both cards....

Also Crossfire does depends on what type of CPU you use... Crossfire/SLI will seriously be effected if you use a low end CPU.....

It also depends on the chipset... if the chipset supports two PCI-e x16 2.0 lanes then that would be better. If one is x16 and the other x8 then both will become x8 when Two cards will be in Crossfire/SLI configuration... You should read motherboard manual to know the exact info....

Message quoted 1 times

Reply to enayet_redeemer

enayet_redeemer wrote :

I don't think your motherboard supports Crossfire.

And regarding effieciency.. if two cards are in Corssfire then the load will be divided equally. Typical effieciency is in between 50-70% for both cards....

Also Crossfire does depends on what type of CPU you use... Crossfire/SLI will seriously be effected if you use a low end CPU.....

It also depends on the chipset... if the chipset supports two PCI-e x16 2.0 lanes then that would be better. If one is x16 and the other x8 then both will become x8 when Two cards will be in Crossfire/SLI configuration... You should read motherboard manual to know the exact info....

hi,my mainboard can support crossfire according to its user guide and box,and I have one PCI-e x16 and one PCI-e x4,my cpu is core 2 duo e6750.and I have 2 gig ocz ram

Reply to ethilen

Exactly. Your (and mine as well, I have the P5K-E premium with Wifi) does support CF, but because the one slot is x4, both will act like x4 slots. Toms did an article with CF in different configs, and its actually slower to CF on our board then to use a single high end card. You can stick an Nvidia card in there for a PhysX card, but I wouldn't try to CF.

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Reply to 4745454b

With your P35 based motherboard it would be better to avoid CrossFire.
PCIe 1 16x/4x CrossFire Scaling is atrocious and can be even slower than a single card in some cases.
If you wish to run two 4850's I would recommend upgrading to a decent ASUS or Gigabyte P45 based motherboard.

Message edited by outlw6669 on 09-20-2009 at 05:15:31 PM

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Reply to outlw6669

What resolution to use? That's the most important thing to know. If it's 1650x1050 (22" ) or less then you don't need to use Crossfire anyway; just get one decent card like a 4870 (or wait a couple weeks for the 5870's).

Message quoted 1 times

Reply to jevon

Damn you outlaw, I just looked up that article

http://www.tomshardware.com/review [...] 095-5.html

Avoid CF with this motherboard, its for the best. (still a good motherboard, just not worth CFing on.)

Message quoted 1 times

------------------------------ The voice of REASON
Do NOT feed the TROLLS!
Always a DEMON!
Reply to 4745454b

I aim to please

Message quoted 1 times

------------------------------ If the automobile had followed the same development cycle as the computer, a Rolls-Royce today would cost $100, get a million miles to the gallon, and explode once a year, killing everyone inside.
PSA
Reply to outlw6669

jevon wrote :

What resolution to use? That's the most important thing to know. If it's 1650x1050 (22" ) or less then you don't need to use Crossfire anyway; just get one decent card like a 4870 (or wait a couple weeks for the 5870's).

I wanted to buy two 4770 and use them as crossfire,and I wanted to play at 1920x1080,but I searched and found out that with crossfire4770 I will not be able to play at this resolution due to my mainborad chipset,I mean I can play but I will have problems in frame rate or God knows what,and now I want to buy 4890 instead of that 4770crossfire,what do you think?

Message edited by ethilen on 09-21-2009 at 01:33:14 AM

Reply to ethilen

outlw6669 wrote :

I aim to please

THANK YOU SO MUCH,THAT LINK WAS EXACTLY WHAT I WAS LOOKING FOR ON THIS SITE BUT I COULDNT FIND IT,I DO APPRECIATE THAT

Reply to ethilen

4745454b wrote :

Damn you outlaw, I just looked up that article

http://www.tomshardware.com/review [...] 095-5.html

Avoid CF with this motherboard, its for the best. (still a good motherboard, just not worth CFing on.)

THANK YOU SO MUCH

Reply to ethilen

4890 is a good idea, so is the GTX275. I'd get whichever is cheaper. Both are good for 1920x1080. If you have the cash to spend you can get the X2 cards, but they cost quite a bit.

------------------------------ The voice of REASON
Do NOT feed the TROLLS!
Always a DEMON!
Reply to 4745454b

Focus On

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