HD 4850 crossfire Question

[jmc007]

I currently have a 512mb HD4850 gs, I am thinking of getting another in crossfire mode. Would a 1gb 4850 be better than another 512mb for this.(I have heard only 1 cards memory is used.)
Or would an upgrade to a gtx275 or 4890 be a better choice? I am still not sure about the pci slots GPU performance on my P5Q (i.e. Only one card in x16, 2 at x8?)



I am getting ready for MafiaII.




[email protected] vcore1.275 P5Q Deluxe Xigmatek 1284ee
4gb OCZ Reaper HD 4850 gs 60gb Maxtor IDE(We all have a budget)

 

[Heretic1322]

You would only use half of the RAM on the 48501gb, so it would be a waste

Go for the best single card you can afford

 

[Alpherah]

went from cf4850's to gtx 275 which i OC'd to almost 285 levels.
Overall performance stayed about the same, lol.
Higher in apps with low / no CF support, lower in those with good cf support.
Its a lot quiter and cooler then the cf4850's though.

 

[Subliminal Aura]

^^

Indeed.

Only thing to look out for with xfire is to ensure that your board can do 8x/8x at a minimum or else you'll be wasting a little juice.

 

[jmc007]

Cheers you guys. =) lol
Reckon she's crying out for another card in there. My currently unused blowhole would do the job on the extra heat I reckon.

Cheers again.

 

[jmc007]

I am still not sure though. =) Will probably wait to see how MafiaII performs with crossfire.

 

[reflux]

Bang a second one in!!!

**if you are running at 1680x1050 or above.

 

[Alpherah]

I also noticed the effect its had on my processor temp too :O
Using latest realtemp, my idle temps for my E8400 at 3.8Ghz was 44 degrees with the CF4850 setup, its now 29 degrees, so quite likely i can bump it upto 4ghz at last, and this is with the "old" Stepping which needs higher volts.

 

[Subliminal Aura]

motherboard temps were my issue - both cpu and motherboard temps went up at least 10Cs. GPUs were at 90C full load.

63C on the motherboard got me worried so ended up sorting out the airflow in the case.

Seems like I had the airflow all wrong in the case. Now I'm quite happy with 50C on both the CPU and motherboard. GPUs full load are now 65-70C.

Note these temps are for a machine that runs full load on both the gpus and cpu 24/7 so I'm quite happy with 50/50