HELP!! 2 HD4850 in CF or 1 HD4870

[ghostmann]

Hey Guys,

IS it better to get 2 HD4850 in CF vs. 1 HD4870? I'am replacing 2 HD3870 with either one above. However if I do go with HD4870 and then crossfire them later. I would have to upgrade my power supply from what I have which would bring the cost up. Let me know what you guys think here are my specs below and what games I play.

Intel 975XBX
2 gigs DDR2 800 crucial ballastix
2 74g raptors in raid 0
Corsair 620HX power supply
Q6600 @ 3.0ghz
Audigy 2ZS
40" LCD runnign 1920x1080 thru HDMI

Crisis
COD4
Supreme Commander
WIC
source games
up coming starcraft 2 (whenever it comes out

Thanx
Ghostmann

 

[NarwhaleAu]

I am facing the same question...

I am thinking that a single HD4870 is what I want, then wait another year and go crossfire.

Either way you are going to see a bit performance boost.

 

[aevm]

I suspect you'll have a bottleneck with your PCI-E 1 slots. I saw an article that showed bottlenecks with HD 4850 CF on a P45 chipset, i.e. with PCI-E 2 slots running at x8. That's the same bandwidth as your PCI-E 1 slots at x16.
http://www.tweaktown.com/articles/1472/intel_p45_vs_x48_crossfire_performance/index.html

To solve that, you need something like GA-EX38-DS4 or GA-X48-DS4 or P5E X38 or aBit IX38 QuadGT or whatever (X38 or X48).

HD 4870 < HD 4850 CF < HD 4870 CF, so you have to decide if you accept less performance now (a single HD 4870) + more performance later (HD 4870 CF), or just go with HD 4850 CF and stay there. That depends on you totally.

I've seen people running HD 4850 CF on a 620HX, so I think you're OK. I'd prefer a 750TX or Silencer 750W for it, and especially for HD 4870 CF, but I think the 620HX can handle that too.

CoD4 benefits a lot from Crossfire. Crysis less. Starcraft 2 will probably not be very demanding, because Blizzard traditionally aims to make their games accessible to lots of people.

 

[hannibal]

Two 4850 = $400
one 4870 = $309

At this moment cg 4850 offer more bang for the buck, but as it was said above, 4870 offers more in future. In few years GDDR5 is not so expensive as now, so it's possible to see relatively cheaper 4870's. The prize of GDDR3 is not gonna come down at same speed. After a while it will be more expensive to produce.

 

[ghostmann]

The reason I'm changing from 2 HD3870 because I sold them at a good price and sold my old processor so the funds are ava. As for perfomance HD4850's in CF ourperform HD 3870's CF by a significate margin. Thanks for your help

 

[aevm]

This might help.
http://hothardware.com/Articles/ATI_Radeon_HD_4850_and_4870_RV770_Has_Arrived/?page=10

They don't have benchmarks for HD 3870 CF in that article, but the 3870X2 is a pretty good equivalent. In Crysis, HD 4850 (28 fps) and HD 3870 X2 (30 fps) are about the same, and a single HD 4870 (35 fps) is an improvement, and two HD 4870 give 46 fps.

 

[aevm]

wouldnt the 2 3870's be better than 4850/4870?

4850 <= 3870 CF < 4870, apparently. I posted the benchmark link earlier, check it out. I must say, that 4850 is better than I expected

 

[hannibal]

This might help.
http://hothardware.com/Articles/ATI_Radeon_HD_4850_and_4870_RV770_Has_Arrived/?page=10

They don't have benchmarks for HD 3870 CF in that article, but the 3870X2 is a pretty good equivalent. In Crysis, HD 4850 (28 fps) and HD 3870 X2 (30 fps) are about the same, and a single HD 4870 (35 fps) is an improvement, and two HD 4870 give 46 fps.

CF does not seem to work very vell in crysis a this moment...

 

[kpo6969]

http://www.guru3d.com/article/radeon-hd-4850-and--4870-crossfirex-performance/

 

[hsarc]

I think you are better off with the one 4870 with high resolution due to the amount of memory bandwidth compared to the 4850.