DO WANT, but the power consumption would make me think otherwise. That's a LOT of juice. Even at the more moderate thought of ~293w TDP, ...eff. powerbills will skyrocket. Turn on the PC, play a game, brownout the house. Heck, if you live in California, play a game, brownout the city.
Much as that card makes me drool, the best I'll probably end up with is likely a 5870 paired with a 5850. Since you CAN put different models together, it makes it hard for me personally to justify having 2 of the more expensive one, especially on my budget.
Lordbean, Don't mix em, the 5850 will limit the 5870 and you will just end up for the performance of two 5850's anyway.
I'm actually leaning t words buying a single 5850 for now, selling my old card it should only be about a $150 net expense while offering me about a 40% performance gain but most importantly the new features. I'll smack a 2nd board on when practical.
For $259 the 5850 is the best deal of the bunch and you really are not giving up that much.
Lordbean, Don't mix em, the 5850 will limit the 5870 and you will just end up for the performance of two 5850's anyway.
Actually, unless the 5000 series has a behavior change in this regard, it won't limit the 5870 at all. The 4000 generation crossfire is not limited by the slower card, and I've confirmed this for myself... I ran my primary HD4850 at full speed and my slave 4850 at half clock, and it made zero performance difference in games, benchmarks, etc.
Actually, unless the 5000 series has a behavior change in this regard, it won't limit the 5870 at all. The 4000 generation crossfire is not limited by the slower card, and I've confirmed this for myself... I ran my primary HD4850 at full speed and my slave 4850 at half clock, and it made zero performance difference in games, benchmarks, etc.
I never understood it to be that way? I always thought the lesser card was the limiting factor in a crossfire setup? In other words it would clock to the lower variable, as well as limit the total number of stream processors available. Say you pair a 4870 with a 4830 each card will run 640 streams clocked down to the 4830's speed, or so I thought?
I'd love to get some performance benefit by slapping a 5850 on the board with the 4870 I have, I just figure I will loose the DX11 features and I will be limited, in short, the 5850 will only perform as well as a 2nd 4870?
I don't recall where I found the article on this, but that analysis isn't true, and AMD themselves has even said so. The only thing you can't mix and match on 4000 series cards is RAM sizes - if you stick a 4870 1GB with a 4850 512MB, the 4870 will only use 512MB of its own RAM, but it does not clock down to match the 4850's clocks or stream processors.
Cliff, EDIT: Daedalus685, and Ray Adams are incorrect.
Putting two disparate cards from the same family into a CF configuration will only limit total memory capacity to that of the board with the most VRAM (e.g. 512+1024 = 1024 in CF). In all other ways, both cards will operate at their full capacity.
At the end of the day, this is still more about picking who to believe than anything... I'm going to re-run the benchmarks on my Phenom II rig using both cards at full speed, and then with the slave 4850 downclocked. This should give more definitive answers to the question. I realize the number of stream processors is going to be the same, but by forcing asynchronous clocks I at least should be throwing the primary card out of whack, if ray adams is correct.
Edit - typing while Thrax posted. Appreciate that I'm not alone in this.
Cliff, EDIT: Daedalus685, and Ray Adams are incorrect.
Putting two disparate cards from the same family into a CF configuration will only limit total memory capacity to that of the board with the most VRAM (e.g. 512+1024 = 1024 in CF). In all other ways, both cards will operate at their full capacity.
Well, I have a 4870 with 1024 Ram DDR5, so not much of a limiting issue there.
Hypatheticly, I get a 5870 board, slap it on, am I running 1600+800 = 2400 total stream processors? Will my system setup be capable of running DX11? Will it run DX11 while leveraging the assets of both cards?
You cannot mix card families. A 3xxx cannot be paired with a 4xxx or 5xxx, nor can a 4xxx be paired with a 5xxx. The drivers will not enable CrossFireX.
Well, I have a 4870 with 1024 Ram DDR5, so not much of a limiting issue there.
Hypatheticly, I get a 5870 board, slap it on, am I running 1600+800 = 2400 total stream processors? Will my system setup be capable of running DX11? Will it run DX11 while leveraging the assets of both cards?
No to all questions. You cannot mix and match different generations of cards - AMD has also said that. I wouldn't even try it myself due to different DirectX versions.
They have previously stated that matching 4xxx with 4xxx is fine, 3xxx with 3xxx is fine, etc, but you can't put a 3xxx with a 4xxx or any other such combination and expect it to work, because it won't.
I still intend to go through with my above post when I get home from work. I'm going to run a testing battery on my 4850s using both at full speed, and then the slave at half speed, and then both at half speed for good measure, and see what I turn up. That should help demonstrate the workings of the technology a little better.
Cliff, EDIT: Daedalus685, and Ray Adams are incorrect.
Putting two disparate cards from the same family into a CF configuration will only limit total memory capacity to that of the board with the most VRAM (e.g. 512+1024 = 1024 in CF). In all other ways, both cards will operate at their full capacity.
Okay, I believe Thrax too
How efficient the driver does load balancing between the two different cards? Can both cards be used at full capacity? Or the faster card idles a little to wait for the slower card?
CrossFireX scalability really depends on the game, and the API (DirectX vs. OpenGL). DirectX scaling has received the most work, as the majority of today's titles are based on DirectX. Secondly, the X2 cards typically scale better than paired cards... There are many reasons for this, but they're immaterial to the question.
Given these caveats/exceptions, a performance breakdown of the 4xxx series would look something like this:
Thanks for the reply. I am amazed with ATI's work on CrossFireX. I am thinking about the cluster computers we run, I can not imagine how balancing would work with different CPUs. But you are right it must depend on the parallelism of the task, the particular game in Crossfire case.
Thrax
🐌Austin, TX Icrontian
Comments
Is there a case on earth that will fit that thing? Might be an issue?
Want.
HHHNNNNNNNGGGGGGGG
!!!
DO WANT, but the power consumption would make me think otherwise. That's a LOT of juice. Even at the more moderate thought of ~293w TDP, ...eff. powerbills will skyrocket. Turn on the PC, play a game, brownout the house. Heck, if you live in California, play a game, brownout the city.
I'm actually leaning t words buying a single 5850 for now, selling my old card it should only be about a $150 net expense while offering me about a 40% performance gain but most importantly the new features. I'll smack a 2nd board on when practical.
For $259 the 5850 is the best deal of the bunch and you really are not giving up that much.
Actually, unless the 5000 series has a behavior change in this regard, it won't limit the 5870 at all. The 4000 generation crossfire is not limited by the slower card, and I've confirmed this for myself... I ran my primary HD4850 at full speed and my slave 4850 at half clock, and it made zero performance difference in games, benchmarks, etc.
I never understood it to be that way? I always thought the lesser card was the limiting factor in a crossfire setup? In other words it would clock to the lower variable, as well as limit the total number of stream processors available. Say you pair a 4870 with a 4830 each card will run 640 streams clocked down to the 4830's speed, or so I thought?
I'd love to get some performance benefit by slapping a 5850 on the board with the 4870 I have, I just figure I will loose the DX11 features and I will be limited, in short, the 5850 will only perform as well as a 2nd 4870?
http://forums.guru3d.com/showthread.php?t=275077&page=34
http://forums.amd.com/game/messageview.cfm?catid=262&threadid=115144&highlight_key=y&keyword1=mixed%20crossfire
Scroll down to the moderator's post.
Putting two disparate cards from the same family into a CF configuration will only limit total memory capacity to that of the board with the most VRAM (e.g. 512+1024 = 1024 in CF). In all other ways, both cards will operate at their full capacity.
Edit - typing while Thrax posted. Appreciate that I'm not alone in this.
Well, I have a 4870 with 1024 Ram DDR5, so not much of a limiting issue there.
Hypatheticly, I get a 5870 board, slap it on, am I running 1600+800 = 2400 total stream processors? Will my system setup be capable of running DX11? Will it run DX11 while leveraging the assets of both cards?
No to all questions. You cannot mix and match different generations of cards - AMD has also said that. I wouldn't even try it myself due to different DirectX versions.
They have previously stated that matching 4xxx with 4xxx is fine, 3xxx with 3xxx is fine, etc, but you can't put a 3xxx with a 4xxx or any other such combination and expect it to work, because it won't.
Okay, I believe Thrax too
How efficient the driver does load balancing between the two different cards? Can both cards be used at full capacity? Or the faster card idles a little to wait for the slower card?
http://www.legitreviews.com/article/663/1/
Given these caveats/exceptions, a performance breakdown of the 4xxx series would look something like this:
4890 CrossFire
4870 X2
4870 CrossFire
4870 + 4850 CrossFire
4850 X2
4850 CrossFire
4890
4870
4850
As you can see, the 4870+4850 comes in ahead of a dual-GPU 4850 solution, but behind a CF 4870 array.
In all the circumstances described above, the cards are working at their maximum capacity with respect to the scaling offered by the title.
Hmm. Seems that article already did my intended work for me.
I'm still likely going to try a 5870/5850 configuration eventually, so we'll see if the technology works as well in the 5000 series.