SLI / CrossFire FAQs

[Maziar]

Btw i did a google search about iZ3D,its somehow like Nvidias 3D view,which as i said is mostly advertising for now and has a long way ahead of it.

 

[shergar]

I have an asrock 775i65gv whats the max ram i can use?fastest gfx card i can run? i have p4 3.40ghz Will it run far cry 2 comfortably? thnx

 

[nukemaster]

The problem with your board is that its AGI("AGP 4/8 compatible") port is more or less 2 PCI slots(The chipset has NO AGP support, but mushing 2 PCI slots works, but the performance hit can be bad). As such the only cards that have been tested are listed on the Asrock site. Other cards "may" work, but there is no way to know for sure.

http://www.asrock.com/mb/vga.asp?Model=775i65gv&s=775&c=VGA

As for memory, The max is 2 gigabytes. 2 x 1gig sticks. The top memory speed supported is DDR PC3200(400mhz)

If you can get a decent card farcry 2 may run at lower end settings, but that would be about it.

 

[Fence82246]

Just a little help here...

I'm upgrading my entire system and trying to decide which Graphic Card to go with...
My old system is a has a AMD 64x2 @3800, 2GB Ram, 8800GT 512mb
My new system will be a Intel i7 920, 6GB, and ???? Video card...here is where I need your help.

I currently have a 8800GT 512mb...

I've been very happy with the performance of this card and it has extended the life of my computer...but again...time for a new system.

I am having a custom system built and can have a 9800GT 512mb installed...but no 8800GT. I can go as high as the ATI 4870 card as well...

I read the FAQ where it indicated that you must have 2 of the same videos cards to run SLI...but I also read on THG that the 9800GT 512mb is just a repackaged 8800GT.

My questions are:

1) Can I use an 9800GT in SLI with my 8800GT...?

2) Would 2 x 8800GTs in SLI be better than running 1 x GTX280?
* Seeing as I can purchase a 8800GT 512mb for around $120.00 this could save me quite a bit of $$$

3) Or for that matter...running 3 x 9800GT vs 1 x GTX280 (or better...285)

This has become very confusing to me...

Thank you in advance for any replies.

 

[Maziar]

1_No
2_It depends on the resolution that you play at
3_Again it depends on the resolution that you play at.(But i don't recommend 3-Way SLI,because of heat,power consumption and also it doesn't always triple the performance)

 

[Fence82246]

I am using a Gateway FPD2485W as my monitor running at 1900x1200...

 

[Maziar]

In that case,you will benefit from SLI/CF,you may want to look at dual video cards too like HD 4870X2 or GTX 295,i myself have a HD 4870X2 and i am happy with it.

 

[Max Lazer]

I think I understood the FAQ, but I wanted to be absolutely sure of this first.
I currently have a Visiontek HD 4850 card running, and I plan on buying a new card soon (preping for Empire: Total War). I was originally planning on buying from Newegg, but they no longer have a Visiontek 4850.
Amazon does appear to have the card, as does Micro Center. However, Newegg also has two cards that, as far as I can tell, are roughly the same clock and memory speed. However, they are from different manufacturers.
What I'm trying to be sure of is whether it's risky to buy from a different manufacturer and run CrossFire, or whether it's a relatively safe (and, as far as I can tell so far) cheaper move.
I also noted that one of the cards that Newegg has uses DDR4 memory instead of DDR3, so I'm wondering if that makes it incompatible.
Any thoughts would be helpful; in the meantime, I'm going to keep looking around for cards...

For the time being, here's some info, if it does any good:
My current video card: http://www.microcenter.com/single_product_results.phtml?product_id=0291846

Cards I ran across on Newegg: http://www.newegg.com/Product/Productcompare.aspx?Submit=ENE&N=40000048&Description=4850&CompareItemList=N82E16814140098%2CN82E16814161244&page=2&bop=And

They got the idea in my head, but I may find others.

 

[Maziar]

You "Can" crossfire your current card (which has 625MHz Core Clock Speed and GDDR3) with both of those cards in the neweggs link,but i dont recommend it,because:

1_The Appolo card has the same clock/memory speed but its GDDR4 and yours is GDDR3.

2_The HIS one has a little more core clock speed than your current card.

Here are 4 cards which has the same specification of your card and i recommend them to be crossfired with your card:

http://www.newegg.com/Product/Product.aspx?Item=N82E16814102770
http://www.newegg.com/Product/Product.aspx?Item=N82E16814161259
http://www.newegg.com/Product/Product.aspx?Item=N82E16814121295
http://www.newegg.com/Product/Product.aspx?Item=N82E16814161243

 

[Max Lazer]

So then it is relatively risk free to combine different brands? Great! That will make things easier. Thanks for the links, too.

*shortly after*
http://www.newegg.com/Product/Productcompare.aspx?Submit=ENE&N=40000048&Description=4850&bop=And&CompareItemList=N82E16814102770%2CN82E16814161243%2CN82E16814121295%2CN82E16814161259
Acht, looking at the cards in comparison brought more questions, not answers
Does the OpenGL matter? One of the cards has OpenGL 2.0 while the others have 2.1. Does that make a large difference? Could I just d/l an update for OpenGL?

And I'm assuming (as I've never heard of it before) that RoHS compliant has to do with this http://en.wikipedia.org/wiki/RoHS and not something else.

 

[Maziar]

I think there is a mistake in newegg,HD 4850 supports Open GL 2.1:
http://ati.amd.com/products/radeonhd4800/specs.html

RoHS,ASUS always advertises about it its not anything important (as i said mostly advertising )

 

[Max Lazer]

Well thank you very much. Now comes the task of figuring out which brand is better. :\

*much later*
I didn't want to make another thread of this, and it is CrossFire related:
I think I've narrowed down my choice of a new card to the HIS 4850 cards.
http://www.newegg.com/Product/Productcompare.aspx?Submit=ENE&N=40000048&StoreType=-1&CompareItemList=N82E16814161243%2cN82E16814161259&Description=4850&bop=And

What I'm contending with is whether to go with the cheaper fan, or, since I'll be running CrossFire, I should shell out the extra $56 for the cooling of the second one.

In addition, on Amazon and Newegg, I found this card: http://www.newegg.com/Product/Product.aspx?Item=N82E16814161244&Tpk=H485QT512P

I noticed that it's memory and clock speeds are a bit faster. If I understand correctly, what this will result in is that this card, were I to get it, would slow itself down to match my slower card.
Is that acceptable, considering the better price I'd be getting for the cooling? (and the additional game)

 

[meodowla]

In that case,you will benefit from SLI/CF,you may want to look at dual video cards too like HD 4870X2 or GTX 295,i myself have a HD 4870X2 and i am happy with it.

I have some questions:
1) Does CF or SLI helps achieve higher resolutions?
2) Is there much difference in performance between HD4850 DDR4 & HD4850 DDR3?
3) I'm using Athlon64 X2 6000+ processor. Does it bottleneck the processor if i use HD4850 in Single mode/CF mode?
4) Which PSU would be better for HD4850. (PSU1, PSU2,PSU3)

 

[Maziar]

Well thank you very much. Now comes the task of figuring out which brand is better. :\

*much later*
I didn't want to make another thread of this, and it is CrossFire related:
I think I've narrowed down my choice of a new card to the HIS 4850 cards.
http://www.newegg.com/Product/Productcompare.aspx?Submit=ENE&N=40000048&StoreType=-1&CompareItemList=N82E16814161243%2cN82E16814161259&Description=4850&bop=And

What I'm contending with is whether to go with the cheaper fan, or, since I'll be running CrossFire, I should shell out the extra $56 for the cooling of the second one.

In addition, on Amazon and Newegg, I found this card: http://www.newegg.com/Product/Product.aspx?Item=N82E16814161244&Tpk=H485QT512P

I noticed that it's memory and clock speeds are a bit faster. If I understand correctly, what this will result in is that this card, were I to get it, would slow itself down to match my slower card.
Is that acceptable, considering the better price I'd be getting for the cooling? (and the additional game)

Note from FAQ:

What about brands ?
Well the brand doesnt matter , again for example , you can use a XFX card with a EVGA card , or a SAPPHIRE card with a DIAMOND card , just make sure they have the same memory and same clocks.

What will happend if 2 cards have the same amount of memory but one has higher clocks than the other?
One of the best ways to learn is to make examples.
You have a 8800GT(Normal edition,no OverClocks) and you want to add another 8800GT(Which is OverClocked),then:

1_The OverClocked one will lower its clocks to reach the Non-OverClocked card.

2_You can OverClock your card(The one that has Stock frequencies) and reach the OverClocked card.
Remember, you cant ALWAYS OverClock the normal card to reach the other card,because it may not OverClock that much and may become unstable.

WARNING:There are many exceptions in Computer Hardware, for example "Mousemonkey" a member of this forum has told me that when he puts his ASUS 7900GT card (Which is at stock speeds) with a XFX 7900GT(A OverClocked card) the ASUS one raise its clock to reach the XFX one which is an exception and as i said exceptions are alot in Computer Hardware.

Between those cards as i said go for the one which has the same specifications like your card,If you can afford the model which has better cooling,go for it.

 

[Maziar]

I have some questions:
1) Does CF or SLI helps achieve higher resolutions?
2) Is there much difference in performance between HD4850 DDR4 & HD4850 DDR3?
3) I'm using Athlon64 X2 6000+ processor. Does it bottleneck the processor if i use HD4850 in Single mode/CF mode?
4) Which PSU would be better for HD4850. (PSU1, PSU2,PSU3)

1_No,multiGPU doesn't raise the resolution,resolution depends on the model and specification of your monitor.

2_No

3_Athlon X2 6000 is a good processor and you will be fine when you put a HD 4850 in your system(however in some very intensive CPU games like World in conflict,supreme commander and mostly RTS game,your CPU may bottleneck)

4_All of them have actually same specifications.

 

[meodowla]

1_No,multiGPU doesn't raise the resolution,resolution depends on the model and specification of your monitor.

Thanks for the reply. My First Question was
Does CF or SLI helps improve gaming in higher resolutions(I mean resolutions like 2560x1600)?
Sorry for my bad English.
And regarding the second question, i still have doubt. As then, what is the purpose of DDR4 memory then.

 

[Max Lazer]

Note from FAQ:

What about brands ?
Well the brand doesnt matter , again for example , you can use a XFX card with a EVGA card , or a SAPPHIRE card with a DIAMOND card , just make sure they have the same memory and same clocks.

What will happend if 2 cards have the same amount of memory but one has higher clocks than the other?
One of the best ways to learn is to make examples.
You have a 8800GT(Normal edition,no OverClocks) and you want to add another 8800GT(Which is OverClocked),then:

1_The OverClocked one will lower its clocks to reach the Non-OverClocked card.

2_You can OverClock your card(The one that has Stock frequencies) and reach the OverClocked card.
Remember, you cant ALWAYS OverClock the normal card to reach the other card,because it may not OverClock that much and may become unstable.

WARNING:There are many exceptions in Computer Hardware, for example "Mousemonkey" a member of this forum has told me that when he puts his ASUS 7900GT card (Which is at stock speeds) with a XFX 7900GT(A OverClocked card) the ASUS one raise its clock to reach the XFX one which is an exception and as i said exceptions are alot in Computer Hardware.

Between those cards as i said go for the one which has the same specifications like your card,If you can afford the model which has better cooling,go for it.

I understand that getting a card that is faster will result in it lowering its speeds. However, considering that one of the cards I looked at is slightly faster, but cheaper than a card of the same brand line that has the same speed as my card, would it be a bad idea anyway.
Would it cause problems, rather than the card simply slowing itself down? If all the card will do is slow itself down to match my current card, then it seems like a good deal to pay $30 less than the card that has the same specs.

 

[Maziar]

Thanks for the reply. My First Question was
Does CF or SLI helps improve gaming in higher resolutions(I mean resolutions like 2560x1600)?
Sorry for my bad English.
And regarding the second question, i still have doubt. As then, what is the purpose of DDR4 memory then.

Yes as i talked about it in the FAQ,multiGPU shines at high resolutions like 1920x1200 and higher.

DDR4 is faster than DDR3 but not much(in HD 4850)

 

[Maziar]

I understand that getting a card that is faster will result in it lowering its speeds. However, considering that one of the cards I looked at is slightly faster, but cheaper than a card of the same brand line that has the same speed as my card, would it be a bad idea anyway.
Would it cause problems, rather than the card simply slowing itself down? If all the card will do is slow itself down to match my current card, then it seems like a good deal to pay $30 less than the card that has the same specs.

can you post the link of these 2 cards please?

 

[Max Lazer]

Here's the card that matches my current 4850:
http://www.newegg.com/Product/Product.aspx?Item=N82E16814161243

Here's the faster, but cheaper card:
http://www.newegg.com/Product/Product.aspx?Item=N82E16814161244&Tpk=H485QT512P

The only differences are that I can see beyond price is that the second one has a core clock speed of 650MHz and a memory speed of 2000MHz, whereas the first card has a core clock of 625MHz and a memory speed of 1986MHz (Micro Center lists my card as having "1000MHz clock, 2000Mhz effective).

Also, I came across this:
http://www.newegg.com/Product/Product.aspx?Item=N82E16814129112
That's what I was going to buy (it's the same as my current card, except with a different cooling system), but they no longer sell it.

 

[Maziar]

Well as i said before you can crossfire your current card with the one that you posted(the second link) but if you can find a card that has the exact specifications of yours,i say go for that to ensure that you won't run in to any problems.

 

[Max Lazer]

Hmm....are there any threads on the forums that discuss using crossfire with cards of different speeds? I'm not sure what search terms to put into Google or the forum search...

 

[Maziar]

Doesnt the FAQ answer your questions ?

 

[Max Lazer]

For the most part, but it doesn't answer the final question I have: would a card lowering its speed potentially cause other problems, or is the lowered clock/memory speed all I'd have to worry about.

 

[Maziar]

mate,mixing 2 cards with different speeds will cause in downclocking the faster card.
I say when there is a card which has the same specification of yours,then why buy a faster card when it wont run at its speed and has to downclock ?