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RV770: ATI Radeon HD 4850 & 4870 analysis

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[USRF]Obiwan 2nd September 2008, 13:23 Quote
An incredible detailed article Tim, kudos!

The biggest shock for me, is the power consumption of the 4870x2. You would suspect it will be side by side with the Nvidia top card in idle power. Is this a design flaw? AMD said they made a power efficient 'something' on the cards to put power to a minimum with idle.

I thought the cards would shut down the 3D hardware in a 2D environment and become active when a application required the need for raw 3D power. Also the power it needs when in performance mode is incredible. Is the 483watts at the socket or the card itself? Its almost 120w more the the GTX280. Makes you wonder what a "GTX280 x2" would suck out of the wall.
Tim S 2nd September 2008, 13:50 Quote
483W is full system load at the socket with a power supply that's about 80 percent efficient at that load.
frontline 2nd September 2008, 14:15 Quote
Great article, well worth waiting for. Thanks!
mrb_no1 2nd September 2008, 14:21 Quote
nice article Smalley, i'll be honest its all a bit too much to digest for me. 16 pages, i think i read 10 but alot of it just goes whooshhhhh over my head. nice article though and for your first major feature after your absence, its a testament to yourself and the support of the staff at bit-tech.

kudos

fatman
Redbeaver 2nd September 2008, 15:08 Quote
in Canada here, the 260s is at the same price point at 4870......
zoot2boot 2nd September 2008, 15:49 Quote
same thing in australia... which probably means ati is making quite a bit more than nvidia on a per card basis.
Horizon 2nd September 2008, 19:16 Quote
Quote:
Originally Posted by zoot2boot
same thing in australia... which probably means ati is making quite a bit more than nvidia on a per card basis.

What they didn't make enough when the were charging $400US for it?
Ontheronix 2nd September 2008, 19:19 Quote
Who will be the first to replace the Vitec 59PR9853 multi-phase by a bigger one ? (see page 5 about power suply of the 4750)
r4tch3t 3rd September 2008, 01:04 Quote
Great article Tim, like most of us here I didn't understand all of it. But it is still very informative and an interesting read. Thankyou.
HourBeforeDawn 3rd September 2008, 01:11 Quote
well that was certainly the best article I have seen in a while from BT, great job, very nice details.
Spaceraver 3rd September 2008, 03:35 Quote
This makes me dizzy.. But kudos to Tim for the effort and for the dizzyness. I love BT for this. (Not to be taken up as any kind of physical effort. :-D )
Nature 3rd September 2008, 07:12 Quote
So what's next from ati and Nvidia and when?

Before or after the yule>?

New or improved architecture>?
leexgx 4th September 2008, 01:10 Quote
Quote:
With all of this in mind, it’s no surprise that AMD hasn’t changed the way power is delivered to the card. 75W of the board’s power is supplied via the PCI-Express interconnect (there’s no support for 150W power draws through the socket on PCIe 2.0 boards) in order to retain backwards compatibility with older motherboards

i am not sure in the above statment is true, on the amd 790 motherboards (prob FX ones as i can on my board m3a32-mpv) you can set the amount of power the PCI-e lane power can have, as i have read about it someware at some point, and the card will accept it (3870 did)
Tim S 4th September 2008, 01:22 Quote
Interesting, I will have to double check that one - thanks!
leexgx 5th September 2008, 02:43 Quote
was quite sure as some users was overclocking there 3870 cards and could get more by setting the option in bios on amd based boards that suported the setting to givemore power down the PCI-e slot (you can even pick witch slot gets more power)
Amon 5th September 2008, 04:19 Quote
Ctrl+D
Tim S 9th September 2008, 15:58 Quote
Quote:
Originally Posted by leexgx
was quite sure as some users was overclocking there 3870 cards and could get more by setting the option in bios on amd based boards that suported the setting to givemore power down the PCI-e slot (you can even pick witch slot gets more power)

I've managed to get around to retesting this and you're right... my bad - I've updated the article to reflect this. Having said that though, the card refuses to work without the 6-pin connector plugged in.
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