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Tons of questions about Crossfire, SLI, PhysX, and more :o

Last response: in Graphics & Displays
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June 23, 2011 3:25:54 PM

Hello all. I want to say thank you ahead of time for reading this thread.

I want to say really quick, Id appreciate it if you guys answered by QUOTING this, picking the questions you can answer, and just making your answers BOLD under my questions, if you guys did that thatd be great!

How much wattage would you guys recommend for a build with 2 x 6870s and an i5-2500K processor?

What motherboards would you guys recommend for crossfiring, either dual x8 or dual x16 that are not too expensive? The more suggestions I could get the better.

Thing is, Im not too experienced with picking video cards, I find myself picking the 6870 again and again for others because I cant find cards that are a lot better unless its $150 more, and that gives like 10-15 FPS, which I dont think is needed if the 6870 outputs 60+ FPS on a 1920 x 1200 res for a game like BC2, maybe you guys can give me different viewpoints on this?

How do 2 x 6870s sound? They have AMAZING performance for the price, very nice budget card in my opinion, I cant seem to justify any other card above that because the performance boost for the price difference just isnt worth it, anyone care to correct me? I dont know much about nVidias cards

Also, how hard is taking apart a video card and applying thermal paste on it? Does it make a big difference, I would assume it would?

Other than the 6870, what cards would you guys recommend crossfiring/SLI...ing >_>?

I had a question about the performance different on a motherboard that has 2 x8 PCI-E slots vs a mobo with 2 x16 slots, is there really that big of a difference? Is it worth getting a mobo that has 2 x16 slots, or is the performance boost minimal? I know they're quite a bit more expensive if Im not mistaken (ANSWERED)

Also, I believe SLI and Crossfire can support up to 4 cards at a time am I right? If not how many for each? (ANSWERED)

If you can have 3 or 4 cards, what is it thats refraining people from putting in lets say 4 x 6990s, I believe this is not possible, someone mind explaining? I know the 6990 is dual-GPU, so why cant we have say 8 GPUs XD? (ANSWERED)

Also, is there any difference between SLI and Crossfire other than one being for AMD and other for nVidia? Is one better than the other? (ANSWERED)

What is PhysX exactly? How is it achieved? I know it's only with nVidia cards. How does it help, which kinds of games does it help in? (ANSWERED)

What is "scaling" exactly? I keep hearing it, never got around to finding out what it was. (ANSWERED)

What are the 2 latest dual-GPU cards for nVidia, I know AMD has 5790 and 6990, and nVidia has a 590 but I dont know what their last gen dual-GPU card was. (ANSWERED)

Would anyone here suggest 5xxx series cards still? Because the 58xx series for example is good, better than most of the 6xxx series, is there any reason someone shouldnt buy a 5xxx series? I feel like new builds are so limited to just the new gen cards. (ANSWERED)

How many FPS would you guys recommend for a very enjoyable experience, I hear 60 a lot. (ANSWERED)

Would getting a say 6870 and 6850 cause conflicts, or maybe bottleneck each other? Im pretty sure you can hook up diff cards although this isnt recommended/common practice? (ANSWERED)


Again please QUOTE the questions you wanna answer and answer below questions in BOLD :o 
June 23, 2011 4:43:55 PM

Yuka said:
http://www.tomshardware.com/reviews/crossfire-sli-3-way...

There you go for all the SLI and XFire related questions.

Cheers!


Doesnt really answer my questions... From what I understand scaling is how much efficiency is added by adding additional cards, so 170% with 2 cards is considered better scaling than 2 cards giving 150% am I correct?

It says 3 way SLI and Xfire but Im pretty sure you can have 4...

Anyone wanna actually answer my questions?
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a b U Graphics card
June 23, 2011 5:23:49 PM

reaper2794 said:
Anyone wanna actually answer my questions?


Not really after that comment. Normally people who need answers are nice about it.
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a b U Graphics card
June 23, 2011 5:28:02 PM

I'll give it a shot:

1.How many PCI-E lanes you have for multi card setups depend on the chipset, like X58 allows for dual x16 while P55, P67 and Z68 supports only dual X8. This is true for SLI as well as Crossfire.

2. The performance difference between PCI-E x8 and x16 in multi card setup is negligible, as long as you compare the same PCI-E version.

3. They can support a maximum of four cards.But you cannot get this for every card. Like GTX 460s are limited to dual SLI, while the GTX 480 can be quad SLI-ed. It also depends on the motherboard. Few motherboards support quad SLI or Quad CrossfireX.

4. Yes, apart from the name there is no difference between SLI and Crossfire. But you can throw in two diffreent cards of the same series like a HD 5870 and HD5850 in crossfire. SLI requires you to have the exact same card. Model must be same, but manufacturer may be different.

5. 4 HD 6990s in Crossfire is not possible because drivers dont support it. Moreover, you'll get huge bottlenecks in such a case.

6.PhysX is a proprietary Physics SDK(software development kit) owned by NVIDIA. It does calculations for Physics effect on a supported GPU. It can be done on the CPU, but NVIDIA intentionally makes it painfully slow on the CPU due to outdated code so that it can get money from developers by making them support it. A limited number of games support it and the benefits are largely superficial. A lot of games can do physics without PhysX, like Crysis.
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a b U Graphics card
June 23, 2011 5:31:00 PM

i'd welcome someone else to continue.........
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June 23, 2011 5:52:02 PM

phishy714 said:
Not really after that comment. Normally people who need answers are nice about it.


I understand what you mean, but you have to understand, Im asking questions, and I get linked to a 10 page article that just talks about scaling, thats basically about it, it answered maybe 2 questions of mine, after me reading through all those pages, I also know how to just google things or give people links, but that doesnt mean its efficient. Its like a kid asking you how to do basic algebra and you hand him a book, the kid can also think of getting a book and reading himself, doesnt necessarily mean thats what hes looking for.

Tamz_msc said:
I'll give it a shot:

1.How many PCI-E lanes you have for multi card setups depend on the chipset, like X58 allows for dual x16 while P55, P67 and Z68 supports only dual X8. This is true for SLI as well as Crossfire.

Interesting, the newest series of mobos support only dual x8? Do you know why? Is dual x16 no longer really necessary or what? I would think theyd make a stronger series or at least the same no?

2. The performance difference between PCI-E x8 and x16 in multi card setup is negligible, as long as you compare the same PCI-E version.

I see, so there really is no point of getting dual x16 mobos? Are you sure? If not then why do they even bother making them or why do people buy them?

3. They can support a maximum of four cards.But you cannot get this for every card. Like GTX 460s are limited to dual SLI, while the GTX 480 can be quad SLI-ed. It also depends on the motherboard. Few motherboards support quad SLI or Quad CrossfireX.

I see, so both support 4 cars, but not every card can do that

4. Yes, apart from the name there is no difference between SLI and Crossfire. But you can throw in two diffreent cards of the same series like a HD 5870 and HD5850 in crossfire. SLI requires you to have the exact same card. Model must be same, but manufacturer may be different.

Interesting, so SLI is at a slight disadvantage on this part

5. 4 HD 6990s in Crossfire is not possible because drivers dont support it. Moreover, you'll get huge bottlenecks in such a case.

I see, assuming someone had a really strong OCed CPU, and the companies made drivers to support it, I guess it would run XD? (I know itd be impractical, just curious)

6.PhysX is a proprietary Physics SDK(software development kit) owned by NVIDIA. It does calculations for Physics effect on a supported GPU. It can be done on the CPU, but NVIDIA intentionally makes it painfully slow on the CPU due to outdated code so that it can get money from developers by making them support it. A limited number of games support it and the benefits are largely superficial. A lot of games can do physics without PhysX, like Crysis.

I see, so PhysX really isnt a big deal? Thats the vibe I got ever since I heard about it, if I were to try to talk someone out of it what would I tell them? Some people seem to think PhysX really helps but have little knowledge about it, Im trying to increase my own knowledge at the same time


Good portion of my questions have been answered, thank you, I hope others can answer the rest?
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a b U Graphics card
June 23, 2011 5:59:34 PM

Its really dependent on the chipset on how many lanes it will support. X58 can support 32 PCI-E lanes, if I'm not mistaken, so it can be split into 4 x 8 to bet a quad GPU setup. This is where the limitations arise in other chipsets. To get more than 2 cards running, they need a NF 200 chip for SLI.
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a b U Graphics card
June 23, 2011 6:01:40 PM

In dual card setups X8 and X16 are equal. On adding more cards, the extra bandwidth in necessary.
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June 23, 2011 6:47:13 PM

Tamz_msc said:
In dual card setups X8 and X16 are equal. On adding more cards, the extra bandwidth in necessary.


Theres absolutely no difference between x16 and x8 with a dual-card configuration?
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a c 272 U Graphics card
June 23, 2011 7:01:27 PM

reaper2794 said:
Theres absolutely no difference between x16 and x8 with a dual-card configuration?

It's minimal, less than 5%.
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June 23, 2011 7:11:25 PM

Mousemonkey said:
It's minimal, less than 5%.


Aah yes, the mighty mousemonkey (bows)

XD

I see, now for all my other questions ._.
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a c 272 U Graphics card
June 23, 2011 7:13:42 PM

reaper2794 said:
Aah yes, the mighty mousemonkey (bows)

Thank you but that's really not necessary. :ange: 
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June 23, 2011 7:47:24 PM

Mousemonkey said:
Thank you but that's really not necessary. :ange: 


Can you answer my other questions? The ones you have the time for? I still dont know if scaling is what I think it is
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a c 272 U Graphics card
June 23, 2011 7:52:51 PM

reaper2794 said:
Can you answer my other questions? The ones you have the time for? I still dont know if scaling is what I think it is

Scaling in layman's terms is the amount of extra fps's you get at the the same settings when the other card(s) are added, if the game in question goes from 50 fps to 100 fps then that would be 100% scaling because the frame rate has been doubled.
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June 23, 2011 7:54:52 PM

Mousemonkey said:
Scaling in layman's terms is the amount of extra fps's you get at the the same settings when the other card(s) are added, if the game in question goes from 50 fps to 100 fps then that would be 100% scaling because the frame rate has been doubled.


Excellent thats exactly what I thought. Ive learned something new, now I gotta start learning how these shaders and clock speeds and all that stuff work

How bout these questions:

How do 2 x 6870s sound? They have AMAZING performance for the price, very nice budget card in my opinion, I cant seem to justify any other card above that because the performance boost for the price difference just isnt worth it, anyone care to correct me? I dont know much about nVidias cards

What are the 2 latest dual-GPU cards for nVidia, I know AMD has 5790 and 6990, and nVidia has a 590 but I dont know what their last gen dual-GPU card was.

Other than the 6870, what cards would you guys recommend crossfiring/SLI...ing >_>?

Would anyone here suggest 5xxx series cards still? Because the 58xx series for example is good, better than most of the 6xxx series, is there any reason someone shouldnt buy a 5xxx series? I feel like new builds are so limited to just the new gen cards.

How much wattage would you guys recommend for a build with 2 x 6870s and an i5-2500K processor?

What motherboards would you guys recommend for crossfiring, either dual x8 or dual x16 that are not too expensive? The more suggestions I could get the better.

Thing is, Im not too experienced with picking video cards, I find myself picking the 6870 again and again for others because I cant find cards that are a lot better unless its $150 more, and that gives like 10-15 FPS, which I dont think is needed if the 6870 outputs 60+ FPS on a 1920 x 1200 res for a game like BC2, maybe you guys can give me different viewpoints on this?

Also, how hard is taking apart a video card and applying thermal paste on it? Does it make a big difference, I would assume it would?

How many FPS would you guys recommend for a very enjoyable experience, I hear 60 a lot.
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June 23, 2011 8:02:30 PM

reaper2794 said:
Hello all. I want to say thank you ahead of time for reading this thread.

I want to say really quick, Id appreciate it if you guys answered by QUOTING this, picking the questions you can answer, and just making your answers BOLD under my questions, if you guys did that thatd be great!

What is "scaling" exactly? I keep hearing it, never got around to finding out what it was.
As far as I remember, scaling is a term used to describe the performance boost when u use sli or crossfire

How do 2 x 6870s sound? They have AMAZING performance for the price, very nice budget card in my opinion, I cant seem to justify any other card above that because the performance boost for the price difference just isnt worth it, anyone care to correct me? I dont know much about nVidias cards
i personally like nvidia cards better, but 2x6870s would be very good, but only necassary if you plan on using multiple monitors, or 1 monitor bigger than 27inches. 1 is enough for pretty much anything else


What are the 2 latest dual-GPU cards for nVidia, I know AMD has 5790 and 6990, and nVidia has a 590 but I dont know what their last gen dual-GPU card was.
im 99% sure the last dual-gpu card from nvidia was the GTX 295, so it was 2 generations ago. I dont think there was any dual-gpu 400 series card


Other than the 6870, what cards would you guys recommend crossfiring/SLI...ing >_>?
I would recommend a gtx 560 ti. I have one of them, and can run every game at max settings, so im sure 2 would be amazing


Would anyone here suggest 5xxx series cards still? Because the 58xx series for example is good, better than most of the 6xxx series, is there any reason someone shouldnt buy a 5xxx series? I feel like new builds are so limited to just the new gen cards.
yes, the the 58xx cards are better than the 68xx cards, so they are a great choice when considering price to perfomance ratio


How much wattage would you guys recommend for a build with 2 x 6870s and an i5-2500K processor?
i would recommend at least a 1000w power supply. But if you google PSU Calculator you will find a bunch of great sites that will tell you how much you need, than get an extra 100 or 200+ watts. I normally use multiple calculators just to be sure im getting the best number

What motherboards would you guys recommend for crossfiring, either dual x8 or dual x16 that are not too expensive? The more suggestions I could get the better.
I love the ASUS ROG series of boards, in my opinion they are the best boards around. They tend to be a little more expensive, but they are amazing quality

Thing is, Im not too experienced with picking video cards, I find myself picking the 6870 again and again for others because I cant find cards that are a lot better unless its $150 more, and that gives like 10-15 FPS, which I dont think is needed if the 6870 outputs 60+ FPS on a 1920 x 1200 res for a game like BC2, maybe you guys can give me different viewpoints on this?
contrary to popular belief, the human eye can see more than 60FPS, so the more FPS the better, it really depends on how much you want to spend.

How many FPS would you guys recommend for a very enjoyable experience, I hear 60 a lot.'
at the very least 60. I normally recommend trying to attain 70 or 80+ because it will allow you to play future games better, and it will look better

Would getting a say 6870 and 6850 cause conflicts, or maybe bottleneck each other? Im pretty sure you can hook up diff cards although this isnt recommended/common practice?
i dont see the reason to get a 6870 and a 6850, you cant crossfire them. hooking up different cards is really only for nvidia, because one can be a dedicated PhysX processor, AFAIK

Is there anything else you guys would like me to know? Haha I hope I asked enough questions! XD

Again please QUOTE the questions you wanna answer and answer below questions in BOLD :o 

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June 23, 2011 8:11:12 PM

reaper2794 said:
Hello all. I want to say thank you ahead of time for reading this thread.

I want to say really quick, Id appreciate it if you guys answered by QUOTING this, picking the questions you can answer, and just making your answers BOLD under my questions, if you guys did that thatd be great!

What is "scaling" exactly? I keep hearing it, never got around to finding out what it was.
As far as I remember, scaling is a term used to describe the performance boost when u use sli or crossfire

How do 2 x 6870s sound? They have AMAZING performance for the price, very nice budget card in my opinion, I cant seem to justify any other card above that because the performance boost for the price difference just isnt worth it, anyone care to correct me? I dont know much about nVidias cards
i personally like nvidia cards better, but 2x6870s would be very good, but only necassary if you plan on using multiple monitors, or 1 monitor bigger than 27inches. 1 is enough for pretty much anything else


What are the 2 latest dual-GPU cards for nVidia, I know AMD has 5790 and 6990, and nVidia has a 590 but I dont know what their last gen dual-GPU card was.
im 99% sure the last dual-gpu card from nvidia was the GTX 295, so it was 2 generations ago. I dont think there was any dual-gpu 400 series card


Other than the 6870, what cards would you guys recommend crossfiring/SLI...ing >_>?
I would recommend a gtx 560 ti. I have one of them, and can run every game at max settings, so im sure 2 would be amazing


Would anyone here suggest 5xxx series cards still? Because the 58xx series for example is good, better than most of the 6xxx series, is there any reason someone shouldnt buy a 5xxx series? I feel like new builds are so limited to just the new gen cards.
yes, the the 58xx cards are better than the 68xx cards, so they are a great choice when considering price to perfomance ratio


How much wattage would you guys recommend for a build with 2 x 6870s and an i5-2500K processor?
i would recommend at least a 1000w power supply. But if you google PSU Calculator you will find a bunch of great sites that will tell you how much you need, than get an extra 100 or 200+ watts. I normally use multiple calculators just to be sure im getting the best number

What motherboards would you guys recommend for crossfiring, either dual x8 or dual x16 that are not too expensive? The more suggestions I could get the better.
I love the ASUS ROG series of boards, in my opinion they are the best boards around. They tend to be a little more expensive, but they are amazing quality

Thing is, Im not too experienced with picking video cards, I find myself picking the 6870 again and again for others because I cant find cards that are a lot better unless its $150 more, and that gives like 10-15 FPS, which I dont think is needed if the 6870 outputs 60+ FPS on a 1920 x 1200 res for a game like BC2, maybe you guys can give me different viewpoints on this?
contrary to popular belief, the human eye can see more than 60FPS, so the more FPS the better, it really depends on how much you want to spend.

How many FPS would you guys recommend for a very enjoyable experience, I hear 60 a lot.'
at the very least 60. I normally recommend trying to attain 70 or 80+ because it will allow you to play future games better, and it will look better

Would getting a say 6870 and 6850 cause conflicts, or maybe bottleneck each other? Im pretty sure you can hook up diff cards although this isnt recommended/common practice?
i dont see the reason to get a 6870 and a 6850, you cant crossfire them. hooking up different cards is really only for nvidia, because one can be a dedicated PhysX processor, AFAIK

Is there anything else you guys would like me to know? Haha I hope I asked enough questions! XD

Again please QUOTE the questions you wanna answer and answer below questions in BOLD :o 


FIRST EDIT:: crossfire can be done with different cards, here is a link to the chart put out by AMD about it:
http://sites.amd.com/PublishingImages/Public/Graphic_Il...

SECOND EDIT:: so yes, it would cause bottlenecks to use a 5870 and a 5850
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June 23, 2011 11:04:57 PM

What do you mean it would only be used for multiple monitors, crossfire is used for 1 monitor all the time... >_>?

GTX 560 Ti's are more expensive than 6870s and dont give a considerable FPS boost if Im not mistaken

Youre saying I need a 1000W PSU for just 2 x 6870s? You're kidding right..?

So can both Nvidia and AMD use diff cards when in SLI/Xfire?
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June 23, 2011 11:35:11 PM

corsair 750 or 850w will be fine for 6870 xfire
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June 23, 2011 11:44:39 PM

0ozee said:
corsair 750 or 850w will be fine for 6870 xfire


Ok thats great to hear! and it wont let me edit my post, why is this forum so buggy >_>
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!