4870 or 2 * 4850 card ?

[triac]

I have the choice of a Sapphire Technology Radeon HD 4870 1GB DDR5 CC 750MHz PCIE 2xDVI card or two XFX ATI Radeon HD 4850 650Mhz 512MB DDR3 PCI-E 2.0 Dual DVI XXX Edition Cards in crossfire.

Any suggestions as I have never run two cards before.

[sandyduff]

What mobo are you running? also what cpu?

[triac]

What mobo are you running? also what cpu?

Going to order a Gigabyte S775 Intel P45 ATX A L Extreme, at present have a dual core 2.6, but will upgrade in a few months, 4gb memory going upto 8gb, 2 fast scsi h/d & 2 500gb SATA drives, 22 inch monitor and a 32inch for occasional use.

[Rich'[ard]]

Going to order a Gigabyte S775 Intel P45 ATX A L Extreme, at present have a dual core 2.6, but will upgrade in a few months, 4gb memory going upto 8gb, 2 fast scsi h/d & 2 500gb SATA drives, 22 inch monitor and a 32inch for occasional use.
that GIgabyte motherboard being a P45...i doubt it'll have 2 PCI-E 16x slots.
you'll need 2 of these slots to benefit the full advantages and speed of Crossfire.
if your second slot is limited to x4 speed, you won't see much performance gain from 1 4850 to 4850s in crossfire.

ppl who go Crossfire usually get X38/X48 boards. these boards have full speed PCI -E 2.0 x16 lanes whicih will give you full speed Crossfire
but if you would like to stick with P45 chipset, you can get the Asus Maximus Formula II which has 2 PCI-E x8 lanes which is nearly as quick as 16x PCI-E lanes. (almost 0.x% difference in speed)

also, with 4850 xfire, that 2.6ghz dual core will definitely be a bottleneck. you should be somewhere in the 4ghz zone for a dual :)

[xtkxhom3r]

in the sticky above it proves that there is little to no difference between dual 8x lanes and dual 16x slots with 4870's so there isnt going to be a problem with 4850's

get a p5q series board bro their better performers

2 4850's will be faster than 4870 but i would get the 4870 so i can add a 2nd one later

here is the link to the sticky http://www.ocforums.com/showthread.php?t=571156

[jokers_greg]

yep, the only time you need true full x16 bandwidth is if you're running very high res, and even there the difference isn't huge.

Pick up a P5Q-E, I've had it for a year now, outstanding board!

[Rich'[ard]]

in the sticky above it proves that there is little to no difference between dual 8x lanes and dual 16x slots with 4870's so there isnt going to be a problem with 4850's

get a p5q series board bro their better performers

2 4850's will be faster than 4870 but i would get the 4870 so i can add a 2nd one later

here is the link to the sticky http://www.ocforums.com/showthread.php?t=571156
those boards are PCI-E 8x as well?
i thought the only P45 board with this was the Asus Maximus Formula II, the one with shiny silver NB heatsinks. :santa:
or are P35 boards the only boards with 16x/4x lanes?

[xtkxhom3r]

;6118527"]those boards are PCI-E 8x as well?
i thought the only P45 board with this was the Asus Maximus Formula II, the one with shiny silver NB heatsinks. :santa:
or are P35 boards the only boards with 16x/4x lanes?

i believe the p35 boards have 16x/4x
the p5q boards (p45) have dual 8x or single 16x
the x48 boards are the ones with dual 16x
and x58 boards (i7) have 16x/16x/8x

[nunez1980]

I have the choice of a Sapphire Technology Radeon HD 4870 1GB DDR5 CC 750MHz PCIE 2xDVI card or two XFX ATI Radeon HD 4850 650Mhz 512MB DDR3 PCI-E 2.0 Dual DVI XXX Edition Cards in crossfire.

Any suggestions as I have never run two cards before.

you already mention the mobo, which is good for crossfire, now the important piece missing is at what resolution you are going to play, which will determine if 512mb is enough,

I would said below 1920x1200 choose the two 4850, which will wipe the floor of the 4870, but if you run at 1920x1200 or above, do yourselfve a favor and choose the 4870 1gb, and down the road you can get another and boost performance another notch

good luck with your choice,

Sam

[hajalie24]

He says he uses a 22" monitor so his resolution is probably 1680x1050. He also said he uses a 32" occasionally and I'm assuming that's 720p