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Videocards - AMD - ATI AMD Radeon graphics cards. Do you have one or want to buy one? Use this forum to discuss anything concerning products using Radeon graphics cards, CrossFireX, from Radeon 9800 to HD 6900


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Does crossfire double your GPUs memory?
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miffywiffy
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Default Does crossfire double your GPUs memory? - 04-16-2012, 11:41 | posts: 521

Games I play like GTA 4 will let me max it out and say the system has 2GB of memory and even my system says it. Yet my Nvidia Machine says I only have 1.2 with SLI and I know the second card is only a mirror or something and that's why it doesn't combine the memory.

Just wondering if this is how AMDS shoddy drivers work or it crossfire works differently to SLI and that's why it's so bad? lol.
   
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Extraordinary
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Default 04-16-2012, 11:44 | posts: 5,830 | Location: 127.0.0.1

No, games sometimes show double the vram but in reality you still only have the amount of ram 1 card has
   
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Pill Monster
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Default 04-16-2012, 11:52 | posts: 23,843 | Location: NZ

No....although technically the available memory is doubled but the data from one card is mirrored onto the other card/s, so you don't really gain anything..

So yeah..no. lol
   
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Lane
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Default 04-16-2012, 12:10 | posts: 5,393 | Location: Switzerland

Crossfire dont create a big memory area accessible from both gpu, each gpu adress their own partition. ( This could change when the Virtual adressable memory will be used, i said could, as normally this is for do a big virtual memory between x86 system memory and the gpu's adressable directly by each the cpu and gpu. )

But there's a particularity with GTA4... I dont remember exactly what was the problem with the way it report memory or use it.
   
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pokerapar88
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Default 04-16-2012, 14:09 | posts: 1,644 | Location: Argentina // Buenos Aires

Quote:
Originally Posted by miffywiffy View Post
Games I play like GTA 4 will let me max it out and say the system has 2GB of memory and even my system says it. Yet my Nvidia Machine says I only have 1.2 with SLI and I know the second card is only a mirror or something and that's why it doesn't combine the memory.

Just wondering if this is how AMDS shoddy drivers work or it crossfire works differently to SLI and that's why it's so bad? lol.
[IMG]http://25.media.***********/tumblr_lx5lqyG19e1qaa7gwo1_400.jpg[/IMG]
   
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Netherwind
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Default 04-16-2012, 14:20 | posts: 1,028 | Location: Sweden

Like they've all said, do not let applications fool you - you still only have 1024MB per card but 2048MB total VRAM.
   
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pokerapar88
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Default 04-16-2012, 15:18 | posts: 1,644 | Location: Argentina // Buenos Aires

Quote:
Originally Posted by Netherwind View Post
Like they've all said, do not let applications fool you - you still only have 1024MB per card but 2048MB total VRAM.
Ummm... no. You have 2048MB of ram, physically, but only 1024MB are used. you can't have applications using more than that. The same data on one card's memory is copied to the other, same as raid 0 setups.

So you have a usable amout of ram equal to the max ram on one card or the min amount if the cards have different ammounts of ram.

if one card is 1024 and the other is 768 you will have 768mb of usable vram
   
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Wrigleyvillain
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Default 04-16-2012, 18:25 | posts: 115 | Location: Chicago

If this were the case many more people would run multi-gpu as it would increase the bang-for-buck value even more.
   
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pokerapar88
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Default 04-16-2012, 18:50 | posts: 1,644 | Location: Argentina // Buenos Aires

Quote:
Originally Posted by Wrigleyvillain View Post
If this were the case many more people would run multi-gpu as it would increase the bang-for-buck value even more.
Yeah, especially for uber high resolution gaming. You could game with 3x 6850 @ 4000p without issues
   
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amieneel
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Default 04-17-2012, 20:07 | posts: 890 | Location: India

gta 4 is buggy !!
   
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