AMD Crossfire System

[NoviceCompGuy]

Hi all,

As I save up for my new PC, I thought I would ask a few more questions. Sorry if these seem stupid, but I am new to this ground up PC building process. I know Intel is faster at the moment, but I prefer AMD. I also prefer ATI cards over Nvidia. So my question is, What would I need to build an AMD Crossfire capable system?

I don't intend to have two video cards at first, but would love to be able to easily upgrade a little ways down the road. Thanks for any help given.

 

[dirtmountain]

In very general terms you'd be looking for a 790x, 790GX or 790FX motherboard, Phenomllx3 or x4 processor and a HD4850 or HD4870 graphic card. Then a power supply sufficient to run 2 of the graphic cards in crossfire (550w to 750w)

 

[aevm]

How much money do you have?

Are you in the USA, Canada, UK, elsewhere?

Do you already have any of these: Windows, monitor, speakers, keyboard, mouse?

 

[fullmetall]

Asus in the 790x, 790gx or 790fx would be a recommended buy IMO.

HD4870 512 are really cheap, and sure they will do a price cut sometime soon so they will drop in price, but, Would preferr a 1gb sapphire "Toxic" for 4870 due to price.

Corsair 750tx
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139006&Tpk=750tx

really good buy, really good product
It has 4x6+2pin connectors to be able to run your crossfire.

Multi-railed psu's are quite interesting but, crossfiring a single rail would probably do a more descent job.

 

[NoviceCompGuy]

Thanks for the info,

@ avem

USA, I have windows xp, but will upgrade to windows 7 when available. My monitor is currently a 19" flat panel, but will be upgraded to a 22" widescreen eventually. Speakers, keyboards, and mice are last on my upgrade list by far.

I prefer the best video card I could find, but there are just so many choices and different price points, I don't know which to choose. Now before I can do any of this price doesn't matter at this point, but I am shooting for a 1,500 to 2,000 dollar build. As I said though, I don't intend to crossfire immediately.

 

[aevm]

Good thing you're in the USA, it means you can buy from Newegg. Much better prices than in other countries.

When you upgrade the monitor you might as well get a 24", not a 22". The 24" monitors are becoming cheaper and they support 1920x1200 rather than 1680x1050. There are also some 22" or 23" monitors that work at 1920x1080.

The HD 4870 1GB is better at handling high resolutions than the HD 4870 512MB, so I'd prefer one of those these days.

There's a HIS version for $235, factory overclocked to 4GHz. There's also a Sapphire version for $200, at stock clocks of 3.6GHz.
http://www.newegg.com/Product/Product.aspx?Item=N82E16814161265
http://www.newegg.com/Product/Product.aspx?Item=N82E16814102801

 

[Helloworld_98]

Not much point in cf'ing 4850's since 4830's in cf beat them...

If you can get two 4870's in your build(which you probably will be able to along with an I7 base) then you'll need a good PSU aswell. Probably a Corsair or Seasonic/Silverstone, their 750w's should be enough for just two cards.

 

[NoviceCompGuy]

Also, the motherboard I am looking at says it is a AM3 socket type and supports phenomII x3 and x4, but when I look at those chips they say that they are for AM2+. Are they compatible or not?

I'll get the hang of this someday!

 

[aevm]

Make sure you get a PSU with 4 PCI-E connectors, because each HD 4870 needs 2.

Corsair, PC Power & Cooling and Silverstone each have at least one 750W model that would do nicely. There's also a Seasonic 700W at Newegg, but it costs more than the others.

 

[aevm]

Also, the motherboard I am looking at says it is a AM3 socket type and supports phenomII x3 and x4, but when I look at those chips they say that they are for AM2+. Are they compatible or not?

I'll get the hang of this someday!

Which motherboard are you looking at?

 

[aevm]

Tell you what, get this combo:
http://secure.newegg.com/Shopping/AddToCart.aspx?Submit=ADD&ItemList=Combo.165047

Phenom II 940 + GA-MA790GP-UD4H 790 GX, $55 off for the combo. You get AMD's best CPU so far and a very good MB (with Crossfire). Also, it works with DDR2 which is a plus compared to AM3 boards because DDR2 is cheaper and still just as fast.

 

[Outlander_04]

Also, the motherboard I am looking at says it is a AM3 socket type and supports phenomII x3 and x4, but when I look at those chips they say that they are for AM2+. Are they compatible or not?

I'll get the hang of this someday!

Its a bit confusing at the moment
AM2+ motherboards use DDR2 memory, which is cheap and fast , and can take AM2 OR AM3 cpu's


AM3 motherboards use DDR3 memory which is just as fast or a fraction faster and costs a lot more .Only AM3 cpu's work in AM3 motherboards

For value right now you stick with AM2+, but with your budget you can easily afford AM3 which makes it more likely you can upgrade at a later stage .
The catch is that the best AM3 gaming cpu is the 720 which is a triple core . They will have better quads available in a few months , but even if you do get a X3 720 its a very good gaming cpu and great value at around $145


With a 22 inch monitor you wont need crossfire . A 4870 1 gig will be plenty . Only consider crossfire with higher resolution monitors

 

[theAnimal]

Not much point in cf'ing 4850's since 4830's in cf beat them...

That's not possible.

 

[NoviceCompGuy]

aevm,

I noticed that motherboard has an onboard video chipset, what does that mean?

Also, what does it mean when it says pci express x16

then one says at x16 and one says x8

btw I am very tired, so I probably won't reply for awhile. See you guys later.

Thanks again

 

[aevm]

That's not possible.

Maybe if the HD 4830 cards are clocked higher, I guess. Or if the numbers are taken from different reviews and the setup with the HD 4850 cards was bottlenecked by CPU/RAM/HDD. Or they are from different reviews and the one with HD 4850 had higher settings or a more demanding area of the game.

Yeah, logically, it makes no sense that two cards with 640 processors beat two cards with 800 processors of the same kind.

 

[aevm]

aevm,

I noticed that motherboard has an onboard video chipset, what does that mean?

Also, what does it mean when it says pci express x16

then one says at x16 and one says x8

btw I am very tired, so I probably won't reply for awhile. See you guys later.

Thanks again

Onboard video means that you can use the PC even if you don't buy a video card. Mind you, onboard video is crappy so you do need a video card for gaming other than Solitaire. It's the best onboard video system available so far, but still crappy when it comes to games. It has 32 stream processors (compare with HD 4850 which has 800 of them). Some games won't even install if they catch you without a video card

PCI-E x16 means two different things, so it's really confusing.

One meaning is the physical size and shape. The GA-MA790GP-UD4H for example has two identical looking slots both called PCI-E x16 as far as shape and size are concerned. That means you can physically stick two PCI-E video cards in it.

The second meaning is about the number of electrical lanes that are available to that slot. Short answer here - you don't care, it's fine. Long answer - with one card you get 16x for the first slot and nothing for the second. With two cards, you get 8x for each slot. That's OK, there's no bottleneck, the performance (with HD 4870 cards or lower, like HD 4850 and HD 4830) is the same as on more expensive 790FX motherboards that do 16x on both slots. This part is only important if you want two HD 4870 X2 cards, but that's overkill and expensive anyway.

In conclusion - get yourself a 790GX board. Either that combo I found for you, or another. Any of them should accept two HD 4870 cards and work well with them.

 

[NoviceCompGuy]

I think I have a build here, but how do I make my wish list public to post it here?

 

[fullmetall]

Also, the motherboard I am looking at says it is a AM3 socket type and supports phenomII x3 and x4, but when I look at those chips they say that they are for AM2+. Are they compatible or not?

I'll get the hang of this someday!

What they did is made the AM2+ motherboards compatible with AM3 chipsets. Why? because, if your doing a budget build, you wont need to worry about overpriced boards. It's to help the people out so when the time comes to upgrade, they only need to get a AM3 board.

so you can get a AM2+ motherboard + Phenom II cpu and DDR2 compatible memory for a less price and just the same amount of power.

So, thus getting PI Black g.skills for tight timing at 2x2gb, P II cpu, am2+ board. etc

but, if your not a big time budget builder, might as well get the full set just like an i7.

 

[aevm]

I think I have a build here, but how do I make my wish list public to post it here?

You could just paste the names of the parts here. People can always go to Newegg and search if they want to see details on a part they don't already know.

 

[NoviceCompGuy]

Yeah, I could do that, here goes;

Case:
RAIDMAX SMILODON Extreme Black ATX-612WEBP 1.0mm SECC Steel ATX Mid Tower Foldout MB Computer Case With 500W Power Supply - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16811156098

Though, I don't want the power supply, so it will either be a spare or ebay fodder.

Mobo:
GIGABYTE GA-MA790GP-UD4H AM2+/AM2 AMD 790GX HDMI ATX AMD Motherboard - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16813128384

Out Of Stock atm, but it will be back, I'm sure

Video Card:
SAPPHIRE 100259-1GL Radeon HD 4870 1GB 256-bit GDDR5 PCI Express 2.0 x16 HDCP Ready CrossFire Supported Video Card - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16814102801

Only one to start with...

PSU:
CORSAIR CMPSU-750TX 750W ATX12V / EPS12V SLI Ready CrossFire Ready 80 PLUS Certified Active PFC Compatible with Core i7 Power Supply - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16817139006

CPU:
AMD Phenom II X4 940 Deneb 3.0GHz Socket AM2+ 125W Quad-Core Black Edition Processor Model HDZ940XCGIBOX - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16819103471

You showed me this and the Mobo as a combo deal, but I can't wishlist them that way. I will try and buy them that way at time of purchase.

Ram:
CORSAIR 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory Model TWIN2X4096-6400C5 - Retail x 2
http://www.newegg.com/Product/Product.aspx?Item=N82E16820145184

I started with 4 x 4GB, but decided to cheapen my build a little in this area

HDD:
Seagate Barracuda ES.2 ST31000340NS 1TB 7200 RPM SATA 3.0Gb/s Hard Drive - OEM
http://www.newegg.com/Product/Product.aspx?Item=N82E16822148278

DVD-ROM:
LITE-ON Black SATA DVD-ROM Drive Model iHDS118-04 - OEM
http://www.newegg.com/Product/Product.aspx?Item=N82E16827106276

Just a reader, for 18x DVD reads

DVD-ROM Burner:
LG 22X DVD±R DVD Burner Black SATA Model GH22NS30 - OEM
http://www.newegg.com/Product/Product.aspx?Item=N82E16827136152

For burning

Cooling compound:
ARCTIC COOLING MX-2 Thermal Compound - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16835186020

Heatsink:
XIGMATEK HDT-S1283 120mm Rifle CPU Cooler - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16835233003

Does this fit my mobo/chip??

Heatsink mount:
XIGMATEK ACK-I7751 Retention Bracket - Retail
http://www.newegg.com/Product/Product.aspx?Item=N82E16835233019


This is my planned build as of now, however I am likely to change something between now and the few months until I can actually afford this system. I am open to ideas, and appreciate any help to make my first build go more smoothly.

Thanks again guys!

 

[dirtmountain]

Since you're going with AMD you won't need that Xigmatek bracket. It's only for socket 775 (intel). The Xigmatek HDT-S1283 is very good and it will fit your case/mobo.
Solid build, anything i could add is nitpicks. Just remember to not use that Raidmax power supply, if you have a boat maybe you can use it for an anchor.

 

[NoviceCompGuy]

Is there a different bracket for the AMD motherboards? I've read that the heatsink itself comes with a crappy attachment method. Though I don't know as I've never done this before.

 

[the1tarheel]

Amd brackets consist of lever locks which connect to the plastic area around the processor. These come with the package. Much safer connection method as you do not have to force the motherboard into weird shapes to lock it in

 

[NoviceCompGuy]

Cool beans, can't wait till I got the money, hope the prices drop by then!!

 

[aevm]

Nice build.

I don't really get the part about the DVD reader. Any DVD burner can serve as a reader too. At least get a second burner, since it's only $5 more anyway.

Check out the NZXT Tempest ($90) and the CoolerMaster RC-690 ($80). They are both bigger than that Raidmax, and both very well cooled. Besides, I don't like the 80 mm fans in the Raidmax. A reviewer describes them as "crazy loud".
http://www.newegg.com/Product/Product.aspx?Item=N82E16811146047
http://www.newegg.com/Product/Product.aspx?Item=N82E16811119137