Games reading my 4870 x2 2048MB as only having 1024MB vram

NeilCardiff · 29 Dec 2008 at 18:33

I have Vista 64 bit the rest of my spec is in the sig.

Does anyone know why this is and how can I fix this problem.

Hope you can help.

gt_junkie · 29 Dec 2008 at 18:36

It only shows 1gb of video ram since each core uses that amount.

So 2x cores equals 2gb of ram.

gt

Lightnix · 29 Dec 2008 at 18:38

It's not an error - it's because you only get an 'effective' 1GB of VRAM to use. The reason is, or so I'm lead to believe, that the VRAM data gets copied across both sets of memory so you really only get 1GB out of the physical 2GB onboard.

NeilCardiff · 29 Dec 2008 at 18:51

Am I correct in thinking it's like crossfire but on one card.

I did think that the games were just reading only half for some reason,

but thats confused me now, do I have 1 or 2gb of usable vram,

the card is advertised as 2 but its missleading if on 1gb is used

Richdog · 29 Dec 2008 at 18:52

1GB on EACH, 2x 1GB cards! It ain't complicated.

(But I can see why you may be mildly confused)

Stonedofmoo · 29 Dec 2008 at 18:55

It's not surprising that so many people get caught out by this. Technically the manufacturers aren't incorrect in saying the cards have 2Gb of RAM. But as it's two physical graphics processors on one card they can only access 1Gb each. End result as any game can only access 1Gb as CrossFire/SLI is 2 or more graphics cores doing the same things in parallel and they all need their own memory.

DeathTyrant · 29 Dec 2008 at 18:56

You have 2x1GB.
Each set of 1GB has identical information as the other. Each GPU is doing it's share of work from the same information.

NeilCardiff · 29 Dec 2008 at 19:04

DeathTyrant said:
You have 2x1GB.
Each set of 1GB has identical information as the other. Each GPU is doing it's share of work from the same information.

Thank you, explained it perfectly.

ashmanuk67 · 29 Dec 2008 at 19:07

so is this the same for 2X 4870 1gig cards

fornowagain · 29 Dec 2008 at 19:09

In crossfire, yes.

NeilCardiff · 29 Dec 2008 at 19:17

That does seem to make sense, am I right in thinking that the gpu's would need to use identical information as they are working on the same task in parallel.

Unlike a multi core cpu that can have different tasks in each core and therefore use different parts of the memory

fornowagain · 29 Dec 2008 at 19:31

Look up AFR, each card creates successive alternate frames.

http://www.tomshardware.com/reviews/nvidia-crossfire,1131-5.html

Shocky-FM · 29 Dec 2008 at 19:35

NeilCardiff said:
I have Vista 64 bit the rest of my spec is in the sig.

Does anyone know why this is and how can I fix this problem.

Hope you can help.

Sorry, you fell for the marketing, it's effectively only 1GB.

elpedro · 29 Dec 2008 at 19:51

Hence why the 9800GX2 fell into deeper s*** earlier; only 512MB

I think the 295 could avoid this slightly with it's wider bus?

NeilCardiff · 29 Dec 2008 at 20:00

fornowagain said:
Look up AFR, each card creates successive alternate frames.

http://www.tomshardware.com/reviews/nvidia-crossfire,1131-5.html

Cheers, Ill have a read of that later

Shocky-FM said:
Sorry, you fell for the marketing, it's effectively only 1GB.

I didnt get it because it was 2gb, 1gb is more than enough for my max resolution, I got it because of the reviews,
But you have a point, it's a bit of a deceptive way to state the vram, 2 x 1gb would be accurate

elpedro said:
Hence why the 9800GX2 fell into deeper s*** earlier; only 512MB

I think the 295 could avoid this slightly with it's wider bus?

Hmmm I bet there were some angry people who couldnt get the resolutions they were expecting

Shocky-FM · 29 Dec 2008 at 20:18

NeilCardiff said:
I didnt get it because it was 2gb, 1gb is more than enough for my max resolution, I got it because of the reviews,
But you have a point, it's a bit of a deceptive way to state the vram, 2 x 1gb would be accurate
(

No need to get defensive, I was only refering the memory as clearly you were not aware the card only had 1GB of memory usable in games and wondered why you couldn't use 2GB, your not the first to fall for that and you wont be the last.

NeilCardiff · 29 Dec 2008 at 21:54

Shocky-FM said:
No need to get defensive, I was only refering the memory as clearly you were not aware the card only had 1GB of memory usable in games and wondered why you couldn't use 2GB, your not the first to fall for that and you wont be the last.

LOL, Not at all, I didnt mean to come across like that, I did understand what you meant.
I was just in a rush when I posted and was trying to say that I did check things out but didnt understand how crossfire used the available resourses.

TheMorningStar · 29 Dec 2008 at 22:02

i heard a tail that ati where looking at changing the way crossfire uses its ram so that the full memory ammount could be used. and that this would be done on the software level so maybe one day that 2gb could be used fully. i ahve no idea if this is correct however or it will ever happen but i thought it an interesting point.

londonbairn · 29 Dec 2008 at 22:18

TheMorningStar said:
i heard a tail that ati where looking at changing the way crossfire uses its ram so that the full memory ammount could be used. and that this would be done on the software level so maybe one day that 2gb could be used fully. i ahve no idea if this is correct however or it will ever happen but i thought it an interesting point.

Would be nice, I am sure ATi are investigating this as they have been more innovative recently with dual GPU cards.

NeilCardiff · 29 Dec 2008 at 23:31

TheMorningStar said:
i heard a tail that ati where looking at changing the way crossfire uses its ram so that the full memory ammount could be used. and that this would be done on the software level so maybe one day that 2gb could be used fully. i ahve no idea if this is correct however or it will ever happen but i thought it an interesting point.

If that is done via software, I hope that means it would just be an upgrade in drivers and maybe waiting for patches to use this rather than any upgrades to hardware. If it could work like that it would give anyone who devised this a massive edge.

rafster said:
Would be nice, I am sure ATi are investigating this as they have been more innovative recently with dual GPU cards.

If innovation is anything to go by as ati came out with the first commercial solution to dual graphics cards then nvidia was close behind, If ati are working on this you can be certain others are also, nice to know technology is driven by us, the consumers. give us what we want or someone else will.