HD 4870 X2 CFX Problems

[hornetx2]

The problem I'm having is that the HD 4870 X2 has a total of 2GB of memory because of two chips. I'm only getting use of 1GB of memory. When I go in to the CCC overdrive I can see on of the chips is working at 99% and the other is just idling at 0%. So I'm only getting use from half my card. My mainboard is the MSI K9A2 Platinum and I have an Apevia 900W PSU. I contacted MSI and it seems they have no clue what there doing. They told me to flash the bios, they gave me the files, and i flashed the bios. Nothing changed so I go back and tell them. They say flash the bios and give me the same files. I did once again just to make sure and no different results (yes, I did reset the CMOS after everytime). After that didn't work they said that they're sorry they can't help and to contact the GPU vendor. So I ask Sapphire and they say that they remember a problem like this and it is the bios... So is there anything I can do or do I have to trash this mobo? CCC is v9.1.

 

[Bluescreendeath]

OS?

 

[hornetx2]

Vista 32 bit. I'm waiting for W7 to come out.

 

[coozie7]

Does n`t the 4870X2 switch off one core when idling? I thought it did to save power, only switching on the second when a 3d app (game) was in use.
Try playing a game, in fulscreen not a window with rivatuner open and logging, I think you`ll find that extra core/memory will kick in.

 

[_DW]

You should and will only see 1GB. 1GB per core, because they do not share memory between the two.
I have the same card and thought I had the same problem before I was pointed in the right direction.

 

[Bluescreendeath]

I was going to say that too, but I thought there was a 4870x2 with an actual 2GB of RAM instead of 1GBx2?

 

[_DW]

not that I am aware of... if so I wish I would have bought that one LOL
The way they do their marketing (make the numbers look good), if they had one with an actual 2GB they would market it as 4GB (2GB X 2), and I have not seen that.

 

[L1qu1d]

Well theres nothing to add

 

[hornetx2]

so then why is my other unit just idling? I understand that I really only have 1 GB (which id say is false advertising, the box says 2GB DDR5). Anyways, should that other unit do something? Its not even heating up so its no good for making smores either...

 

[L1qu1d]

Its not false advertising, because there is 2 gigs, just not working together. I mean its like saying that dual core CPUs are false advertising for not doubling the performance.

Its 2 gigs, 1 per pcb (per card in simple terms or per gpu), its basically mirroring 1 gig. So technically there is 2 gigs on the card, just not being used as 2 gigs, its being used as 1

I might have repeated myself, but I'm a little tired

I'm going to go play some Dreamcast bye bye

 

[hornetx2]

ok i understand but my other unit isnt doing anything. i had rivatuner monitor the cards output while i was playing gta 4 and only one unit is working, the other is just sitting there.

 

[L1qu1d]

hmmm you might need to RMA it.

Are your drivers fully installed?

Run GPU Z and see if Crossfire is enabled.

 

[hornetx2]

it says ATI Crossfire Enable, 2 gpus sideport off

 

[hornetx2]

and yes 9.1 is fully installed. if i have to RMA it would it be better to get the normal 1GB 4870 and actually CF that?

 

[hornetx2]

I have CCC v9.2 installed and the card still seems to be not all that great. I used 3DMark Vantage and on the preformance setting, I'm only getting 15 fps on the graphics test. One core is working at 99.8% and the other is idiling at 0%. Is there something wrong with my card or is it that ATI just makes horrible cards now?

 

[trkorecky]

You should be getting much higher performance in the graphics tests, but you won't see an advantage in GTA IV - Rockstar failed on this behalf and made the port not work with multi-GPU setups (if you check patch one it says they do, but it just fixed a bug where having SLI enabled reduced performance).