Crossfire / CrossfireX ??

[caksey]

Hi all,
Currently got a 2900XT on a AW9D Max motherboard and looking to go crossfire. Was hoping that as the 2900XT are less attractive than the new 3870, they would fall in price to less than the 3870.

No way am I going to pay £235 for another 2900XT, would be better off selling the 2900XT and buying two 3870's!

However, whats with the crossfireX opposed to crossfire? Will my motherboard run two 3870's in crossfire? (or crossfireX)?

 

[gareth170]

crossfirex = 4 cards. crossfire = 2cards..

all crossfire motherboards will run 2 38x0

other option is to buy a 2900pro and flash it to xt.

 

[LoadsaMoney]

Plus with CrossfireX you can mix and match, so you can pair a 3870 with a 3850 for example.

 

[gareth170]

Plus with CrossfireX you can mix and match, so you can pair a 3870 with a 3850 for example.

crossfire u could do that. e.g 1600xt + 1650pro

 

[caksey]

Thanks for the info guys!

Think the 2900 will have to go. 2x3870 costing £318, less about £120 for the 2900 equals approx £200 which is less than a 2nd 2900 !

Plus I could upgrade the motherboard next year and go for 3 or 4 3870s...

 

[bidermaier]

I am not sure that a standard xfire board can run two 3870x2.

 

[Davey D]

crossfirex = 4 cards. crossfire = 2cards..

all crossfire motherboards will run 2 38x0

other option is to buy a 2900pro and flash it to xt.

4 Cards? jeez with a 4 core cpu, and 4x graphics cards, a few hard drives, and maybe a couple of DVD drives how big a power supply will be needed for that lot? maybe get a power station in the back yard?

 

[gareth170]

4 Cards? jeez with a 4 core cpu, and 4x graphics cards, a few hard drives, and maybe a couple of DVD drives how big a power supply will be needed for that lot? maybe get a power station in the back yard?

1 3870 is about 230w at load.. so 230w x 4 = 920w

 

[caksey]

Should be easy enough to rig up two power supplies, one 700w for 2 GPUs and the system and a cheap 500 for the other two GPUs

 

[Dan2kx]

1 3870 is about 230w at load.. so 230w x 4 = 920w

i was under the impression that the 3000 series ran under 100w at load??

 

[gareth170]

i was under the impression that the 3000 series ran under 100w at load??

thats ida
http://www.tomshardware.co.uk/AMD-Radeon-HD-3800,review-29753-18.html

 

[Akhamar]

That 230-260w is for the full system, which is an e6850, 2gb ram etc. so I doubt the 3850 (or 3870) is using a lot of power.

Likely you'd still want a good brand 700w PSU for 4x3850 though.

 

[gareth170]

my mistake... its about 106w for 1 3870...

http://www.legionhardware.com/document.php?id=703&p=7

243 - 137 = 106w

 

[drak3]

would sum up a good 200-250 quid bill if you keep them under load daily