Is the 3870x2 1gb or 512mb \ VOGONS

Is the 3870x2 1gb or 512mb

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First post, by emosun

Posted on 2018-07-23, 02:42

emosun Offline

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lets talk about the 3870x2 because i have one and find it interesting. specifically the 1gb of vram it claims to have. I now understand the card works as such....

it's two separate 3870's each with 512mb of vram. ONE of those 3870's has two dvi outputs , the other has no outputs at all (hence why both outputs still work if you uninstall one of the gpu's in device manager).

Now when in crossfire mode we know that the vram does not combine , just the gpu's themselves. However.... the second gpu has it's own 512mb of vram that... surely must be used for SOMETHING.

Am i to guess that when you crossfire two gpus that the vram doesn't combine but DOES clone each other? Meaning both gpus have the same information in the vram?

Reply 1 of 3, by oohms

Posted on 2018-07-23, 02:56

oohms Offline

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emosun wrote:

Am i to guess that when you crossfire two gpus that the vram doesn't combine but DOES clone each other? Meaning both gpus have the same information in the vram?

Pretty much. Like you said, it is like having 2 separate 3870's (in crossfire), putting them on one card and using the display outputs of only one card

Reply 2 of 3, by agent_x007

Posted on 2018-07-23, 10:22

agent_x007 Offline

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emosun wrote:
Am i to guess that when you crossfire two gpus that the vram doesn't combine but DOES clone each other? Meaning both gpus have the same information in the vram?

That's how both SLI and Crossfire work since introduction 😀
It's also why you never combine VRAM on GPUs.
Only with DirectX 12s new modes for multi GPU support, separating VRAM for each card is possible.