ncclp4f :
Im running a msi radeon hd2600xt 256m core clock is 850 Ive been running star craft 2 on ultra 1280x960 now it will only run it on high at lower res.
you said to get GTX 670 this is a geforce so your saying that geforce works best on crossfire x right ?
the people at tigerdirect said that running two of these cards HIS H545H1GD1 Radeon HD 5450 Video Card - 1024MB DDR3, PCI-Express 2.0 (x1), DVI, HDMI, VGAItem#: H231-5462 | Model#: H545H1GD1 would be like running one of these Visiontek 900338 Radeon HD 6870 Video Card - 1024MB, GDDR5, PCIe, Dual mini-Display Port, HDMI, Dual DVIItem#: V261-6870 | Model#: 900338 I dont think thats true what do you think ?
I'm saying a GTX 670 works better THAN crossfire X, not ON crossfire X. I mean ONE GTX 670 will beat ANY TWO radeons you can buy for 150 bucks any day.
Let's get something clear, crossfire is not an interface, its an optional, additional technology. Any video cards you attach to your motherboard will have to be PCI-E, meaning they will communicate through the PCI Express interface. That can be either a Geforce or a Radeon, regardless of the motherboard supporting Crossfire or SLI. If you want to use two video cards for additional performance, you will need a motherboard that supports either Crossfire or SLI. If it supports SLI, you can use two Nvidia cards. If it supports Crossfire, like yours do, you can use two AMD/ATI cards. Either way, you need two cards of the same model (there was a time ATI supported different models of the same generation, but that never worked well).
What I'm telling you is that, for crossfire to make sense, the combined performance of the two cards need to be considerably higher than that of a single card of equivalent price. If you were to buy a second HD 2600, your performance would still be way lower than a single HD 6870. A GTX 670 will be even more impressive. So, if you can save up and buy a single, powerful card, like the GTX 670, you will end up having a much faster setup.
As for the question about the 5450: A single 6870 is will be worlds faster than 2x5450. Check these links if you want to confirm:
http://www.tweaktown.com/articles/3121/ati_radeon_hd_5450_512mb_gddr3_video_card_in_crossfire/index9.html
http://www.neoseeker.com/Articles/Hardware/Reviews/Sapphire_HD_6870/10.html
Arkham asylum 1680x1050:
HD 6870 = 134 FPS
2x 5450 = 31 FPS
In fewer words, forget crossfire and buy the best card you can afford, Radeon or Geforce.