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2 Different HD4870X2's....

gurusan said:
we did a few random benches and it looks like gDDR5 helps out between 5-10% depending on the game.

Since the 4870 costs 60-70% more I don't think it's worth it...not to mention no one has figured out any vmods yet so that's a major turn off for me. Limited at 800mhz or so = poop :p
Click to expand...

For now. Point is you will be able to overclock higher than 800Mhz in software alone and no pencil mods needed.

Point is 4870 is 30% quicker for 50% more money at stock. If it overclocks in software as well as the 4850 does with bios updates and pencil mods (which a lot of people don't want to do or is beyond them) then the 4870 is worth it IMO.

4850 is a great card for the money though.
 
DarkMatter said:
well im just crossing my figures my P35 mobo wont be crippling ether one of those, what do you guys think?
Click to expand...

I think you will be in bother. The expected performance of the 4870x2 being way above a GTX280 means your poor little 16x pci-e slot is going to take a battering trying to feed all that info to it.

So choices are:

Wait for the 4870x2 to come out and for somebody to try it on a p35 board.

Stop waiting and assume it will be crippled and just get a 4870 or GTX260 now.

Or buy a p45/x38/x48 mobo.
 
Greebo said:
For now. Point is you will be able to overclock higher than 800Mhz in software alone and no pencil mods needed.
Click to expand...

:confused: What brings you to this conclusion?

The 4870 uses 1.263v as opposed to the 1.2v max on the 4850, that's why it can reach 790mhz while the 4850 can't on only a bios flash (limited by 1.2v).

And currently no one knows how to increase voltage on the 4870s, editing the voltage values in the BIOS does nothing. Also, the "super"-4870s by Diamond is only 800mhz, not 900mhz stock. It claims the CCC will be able to slide up to 950mhz though. No one knows how that will be achieved though since it will certainly need more than 1.263vGPU to get there. (I can do 800mhz on 1.263vGPU, anything past that requires more voltage). So everyone is eager for these "super" rv770s to come out so we can see how they manage to increase the voltage.
 
People complaining about 'only' using a 256 bit bus need to read up. There is nothing wrong with a 256 bit bus at all, in fact the bus width is irrelevant as long as the memory can provide enough bandwidth which GDDR5 can.

[edit]

Tom's has a good article on bus width vs memory speed and the different obstacles there are for each.

http://www.tomshardware.co.uk/radeon-hd-4870,review-31046-2.html
 
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Broken Hope said:
People complaining about 'only' using a 256 bit bus need to read up. There is nothing wrong with a 256 bit bus at all, in fact the bus width is irrelevant as long as the memory can provide enough bandwidth which GDDR5 can.

[edit]

Tom's has a good article on bus width vs memory speed and the different obstacles there are for each.

http://www.tomshardware.co.uk/radeon-hd-4870,review-31046-2.html
Click to expand...

All these same people wishing for a 512 bus should be thinking what if ati had used a 512 bus and gddr 5 would we still be seeing the prices going down for the performance we are seeing. I think we would be seeing prices going back to what we were seeing 2 years ago. Ati and nvidia both moved back to a 256 bus and then we started seeing great cards ie. the 8800gt and the 3870xt which were great cards for the price. Imo 256 bus with gddr 5 is the way forward atm.
 
I would've thought that having two 256-bit buses would in effect be like having a 512-bit bus because the two chips will be calling different bits of information at the same time, regardless of whether or not the contents of the memory in both sources is the same.
 
Final8y said:
I get the feeling that the 4870x2 is not doing shared memory hens the need for 2GB which will be 2x1GB
Click to expand...

I have read that aswell, so what the hell happened to all this talk of them working on the memory? Then again, considering they said the card has been kept back so they can work on drivers, that would compliment the idea that it isnt that different from the 3870X2 in delivery (for want of a better term).

Although with THAT said, wouldnt be the first time this year ATi has given us a nice suprise.

Martyn
 
gurusan said:
:confused: What brings you to this conclusion?
Click to expand...

The much better voltage control chips on the 4870.
The extra 75W power supplied to them.
The diamond as stated say it will overclock up to 950Mhz which means just abios change as they won't be doing another pcb with different bits so in theory all 4870's will be capable of 950 with a bios change only.
ATI state there is 55W of surplus power in a 4870 to handle overclocking whereas technically the 4850 doesn't have hardly any at normal stock so yes, your 4850 is very immpressive but I have seen posters who can't get near your clocks.

One 4850 running at 800 does not mean all 4850's will run at 800. I would imagine only a certain percentage will.

I'll be happy with 790/1100 on my 4870 and ecstatic with 950/1200 if all I have to do is change the bios.

But, like you, I am eagerly awaiting the "super" cards.

Plus, I did not realise the 4870 could not be volt modded (yet). I asked on here and nobody answered.

Plenty of people running their 4870 at 870/1125 with no alteration to volts of the card.
 
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wow I see where goldentiger got 870mhz stable. That is impressive indeed. Perhaps I was wrong...perhaps I'll be picking up a 4870 soon for a new toy :p
 
gurusan said:
wow I see where goldentiger got 870mhz stable. That is impressive indeed. Perhaps I was wrong...perhaps I'll be picking up a 4870 soon for a new toy :p
Click to expand...

Well mine isn't coming until next week but I;m aiming for 870/1125 first off. I'm preety sure that will be a step up from my GTS ;)

And if under water later I can get 1000/1200 then that would be an awesome card (let's hope so) :D

Amazing to see that at 840/4400 his 1680 x 1050 crysis 4xaa scores went up from 20 to 25 fps compared to 790/4000.

His 6% core increase and 10% memory increase gave him a 25% boost in framerate.

Looks like these 4870's really start to fly when you overclcok them
 
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Greebo said:
I think you will be in bother. The expected performance of the 4870x2 being way above a GTX280 means your poor little 16x pci-e slot is going to take a battering trying to feed all that info to it.

So choices are:

Wait for the 4870x2 to come out and for somebody to try it on a p35 board.

Stop waiting and assume it will be crippled and just get a 4870 or GTX260 now.

Or buy a p45/x38/x48 mobo.
Click to expand...

i'm tempted by the buying X38 now, i dont feel just getting a 4870 or GTX260 will really change my experience all that much. that would then bring the option in of crossfire, i've always wanted a Xfire setup... but till now its been a waste of time and money! Whats the 9800GX2 like on PCIE16x (v1.1)?
 
I really want a 4870 but i know what will happen it will be bottlenecked by my system and i end upgrading it all and as i got next week off it will be a big temptation to upgrade.
God i must go and play something to get my mind off it ,must stop reading the forums :p
 
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