Question About Crossfiring My Old Computer

[ZZZAAA]

I have an old Powercolor OEM 6970 2GB model and I just realized/remembered that I could crossfire it and get a little more performance out of it before I finish setting up my new rig with Polaris when it releases. Anyway, I saw a Powercolor OEM 6950 1GB model on newegg for a very low price and was wondering about the difference in GDDR5 sizes. Does crossfire use a master/slave relationship where it uses the RAM on the primary card while the second one is there as a supporting role or do the GPU's "mirror" each other where I would get only one GB of GDDR5? I searched all over the net and there wasn't much information on it and people seemed divided on the answer. If any of you has personally tried a similar configuration, please let me know.

Here is a picture of my setup in case you might find a reason crossfire won't work on it:

 

[master_shake_]

maybe look for a 7970/280x or something...

you'll be happier with that.

hell even a decent 290/390

 

[ZZZAAA]

??? I have another skylake 6700k build and I'm planning to crossfire Polaris 10 when it comes out. This one is my old rig and I wanted to know if I could crossfire it to get more performance out of it while I wait. You didn't answer my question at all.

 

[ZZZAAA]

Please someone respond because it might sell out! How compatible is this with the 6970?!

 

[master_shake_]

it's a waste of money and not worth it.

you'll have 1gb of memory and that is just not enough for anything.

 

[ZZZAAA]

To your initial response, the difference between a 200-something card to a $70 card that crossfires is too great to ignore. Are you sure the memory will be stuck at 1gb though?

 

[master_shake_]

To your initial response, the difference between a 200-something card to a $70 card that crossfires is too great to ignore. Are you sure the memory will be stuck at 1gb though?

yes.

it will default to the lowest amount i.e 1gb.

 

[ZZZAAA]

Thanks for your quick response master shake. Really appreciate it. Can someone else tell me how much more performance if any I could get with this potential setup and what single videocard would I be able to compare it to?

 

[master_shake_]

Thanks for your quick response master shake. Really appreciate it. Can someone else tell me how much more performance if any I could get with this potential setup and what single videocard would I be able to compare it to?

http://www.tweaktown.com/articles/3942/amd_radeon_hd_6950_1gb_video_card_in_crossfire/index2.html

 

[ZZZAAA]

Re-opening thread as there seems to be some confusion. Can someone that has tried this kind of setup verify if I would get one or two GB of RAM? I know the AMD website states that RAM speed and clocks will notch down to the lower spec'd card but it doesn't say anything about the size of the RAM itself. Someone please help!

 

[LTC8K6]

It has to drop down to 1gb since that is the limit of one of the cards.

 

[ZZZAAA]

http://www.techpowerup.com/reviews/ASUS/Radeon_HD_6950_CrossFire/

it's also introducing a greater amount of parallelism to the graphics engine, and doubling the standard memory amount from 1 GB in the previous generation Radeon HD 5870 and Radeon HD 5850, to 2 GB on both Radeon HD 6970 and HD 6950. resulting in 4 GB of memory for the HD 6950 CrossFire setup reviewed here

 

[ZZZAAA]

http://www.guru3d.com/articles-pages/radeon-hd-6950-crossfirex-review,1.html

Each Radeon HD 6950 graphics card has 1408 Shader Processors on-board, so for less than 550 EUR you could get a graphics solution with 2816 shader processors and two times 2 GB graphics memory partitions.

 

[ZZZAAA]

So this thing stacks then, correct? If you guys don't know what you're talking about, please don't try to give advice.

 

[gradoman]

So this thing stacks then, correct? If you guys don't know what you're talking about, please don't try to give advice.

Dude, they don't. And in your case, the lesser card, with 1GB, will be the maximum amount used. The end.

 

[therealnickdanger]

For gaming using Crossfire, it does not and will not stack. 1GB+2GB = 1GB. This is the same as SLI. This has been true forever. You will gain *up to* double the processing power of the slowest GPU, but gain *ZERO* VRAM.

 

[ZZZAAA]

I don't understand why in the world it would give double the processing power but not use RAM from one of the videocards. Since when was RAM so special that you could only use one module at a time? Where is your source btw? I have two of them.

 

[MongGrel]

maybe look for a 7970/280x or something...

you'll be happier with that.

hell even a decent 290/390

Pretty much this, not sure why you keep questioning everyone's advice.

 

[Headfoot]

Crossfiring 6970s is a terrible idea and a total waste of time. Buying a (used) 7950 /7970 / 280x / 290 / 290x / 390 is going to be dramatically better in every way for not much more money after you sell your existing 6970.

Crossfiring Polaris 10 is WAY too premature. I wouldn't. We don't know how it performs and crossfire doesnt work quite often on new titles due to the way games are written these days. At least 25% of new games dont support it for months.

Get the single fastest card before you add 2. This is coming from a guy with 2x 290.

 

[ZZZAAA]

How in the world would it give twice the performance using RAM from only one videocard? Please explain that to me.

 

[ZZZAAA]

Headfoot, I doubt I could get even $50 for a used 6970. From my estimations, a USED 280x would cost at least $200. I would be able to get about similar performance for $70.

 

[Headfoot]

Headfoot, I doubt I could get even $50 for a used 6970. From my estimations, a USED 280x would cost at least $200. I would be able to get about similar performance for $70.

No, you won't. Not even close. 6970 uses an unsupported old architecture. It will absolutely tank because it doesn't have enough RAM. You won't get double performance, in fact a lot of the time you wont get any extra performance because 6970 isn't supported any more and 6970 Crossfire will not work in many titles.

Either do a real upgrade to something like a 280x or stay with the single 6970. A second 6970 will just buy you frustration and disappointment

 

[ZZZAAA]

Yes, the 6970's are on legacy drivers now but it shouldn't really matter especially if the games are built on directx 11 or older. I don't think they would program a game to run on a dual setup for each specific card individually. Either the game can use dual GPU's or it can't. I'm seeing a lot of reviews albeit in older titles where the crossfire gives greater than twice the performance of one card especially at higher resolutions (which means that the RAM is kicking in. Anyway, at least one source from any of you would shut me up. I don't think any of you have ever tried this kind of configuration before and I really don't trust your technical knowledge.

 

[MongGrel]

Yes, the 6970's are on legacy drivers now but it shouldn't really matter especially if the games are built on directx 11 or older. I don't think they would program a game to run on a dual setup for each specific card individually. Either the game can use dual GPU's or it can't. I'm seeing a lot of reviews albeit in older titles where the crossfire gives greater than twice the performance of one card especially at higher resolutions (which means that the RAM is kicking in. Anyway, at least one source from any of you would shut me up. I don't think any of you have ever tried this kind of configuration before and I really don't trust your technical knowledge.

Just buy the thing then and stop asking for advice and arguing about the advice you receive.

GL.

 

[ZZZAAA]

Thread is definitely still open.