Crossfire efficiency

[ethilen]

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.

 

[Annisman]

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

 

[enayet_redeemer]

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....

 

[ethilen]

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

 

[4745454b]

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.

 

[outlw6669]

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.

 

[jevon]

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).

 

[4745454b]

Damn you outlaw, I just looked up that article

http://www.tomshardware.com/reviews/crossfire-pci-express,2095-5.html

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

 

[outlw6669]

I aim to please

 

[ethilen]

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?

 

[ethilen]

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

 

[ethilen]

Damn you outlaw, I just looked up that article

http://www.tomshardware.com/reviews/crossfire-pci-express,2095-5.html

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

THANK YOU SO MUCH

 

[4745454b]

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.