Crossfire-Ready or No? Please Help

[oddtodd]

I've been lurking here for a bit while I attempt to build my first computer, and have most of my components picked out I think. I'm trying to make a gaming computer that will last me for a few years without upgrades, then for a few more with some upgrades. So far I have:

Case: Antec Three Hundred Black Steel ATX Mid Tower Computer Case
DVD: LITE-ON 24X DVD Writer Black SATA Model iHAS424-98 LightScribe Support
CPU: Athlon II 640
Power: OCZ ModXStream Pro OCZ700MXSP 700W
OS: Windows 7 Home Premium 64-bit
Memory: OCZ Special Ops Edition 4GB (2 x 2GB) 240-Pin DDR3 SDRAM DDR3 1600
Video Card: HIS Radeon 5770
Hard Drive: TBD, I'll just find the cheapest HD that gives me 500 GB or more
Motherboard: TBD (read rest of post)

Right now, I'm looking at an ASUS M4A79XTD EVO AM3 AMD 790X ATX AMD Motherboard. Basically, I have 2 questions:

1) Because I want this system to last and be upgradeable, I want a motherboard and power supply that can support an additional Radeon 5770 in CrossFire mode. Once the single 5770 is no longer enough for my gaming needs (probably a few years, since I don't need absolute max settings), I figure I can buy another 5770 and just pop it in. Is this worth it? It's probably an extra $50-$75 for this ability, since I need a bigger PSU and a better motherboard, let alone the eventual 2nd 5770.

2) Will that plan work with this motherboard? It says CrossFire compatible, but I noticed it only has 1 PCIe x16 slot, and I think each 5770 needs x16, but am not sure as I'm somewhat of a novice in this field. Is there a better motherboard for this? And if it's not worth it, which motherboard should I go with? Do my other parts make sense as well?

Thanks in advance for any help provided.

 

[compfreak93]

That motherboard has gotten a lot of bad reviews here are 2 other Mobos to consider.

Gigabyte: http://www.newegg.com/Product/Product.aspx?Item=N82E16813128416

Asus: http://www.newegg.com/Product/Product.aspx?Item=N82E16813131646

 

[wielander]

1) Because I want this system to last and be upgradeable, I want a motherboard and power supply that can support an additional Radeon 5770 in CrossFire mode. Once the single 5770 is no longer enough for my gaming needs (probably a few years, since I don't need absolute max settings), I figure I can buy another 5770 and just pop it in. Is this worth it? It's probably an extra $50-$75 for this ability, since I need a bigger PSU and a better motherboard, let alone the eventual 2nd 5770.

The HD 5770s aren't very power hungry. If you are already buying a decent quality power supply, you shouldn't need to worry about power output (500W or more is plenty). I think it's worth it if you plan to purchase the second HD 5770 in the next year or so; after that it may be more difficult to find a suitable HD 5770 and a crossfire HD 5770 setup will be less competitive.

2) Will that plan work with this motherboard? It says CrossFire compatible, but I noticed it only has 1 PCIe x16 slot, and I think each 5770 needs x16, but am not sure as I'm somewhat of a novice in this field. Is there a better motherboard for this? And if it's not worth it, which motherboard should I go with? Do my other parts make sense as well?

The HD 5770 does not require an x16 slot. That motherboard has an x8/x8 mode for crossfire. You shouldn't see any decrease in performance from running an HD 5770 on x8 PCI-E; the HD 5770 can't use up that much bandwidth (two GTX 480s in SLI only show a single digit decrease in performance in 8x/8x).

http://www.tomshardware.com/reviews/pcie-geforce-gtx-480-x16-x8-x4,2696-9.html

 

[dndhatcher]

That motherboard does have two PCIEx16 slots. If you use both of them, only half the lanes will be running, which is called x8 mode. As stated above, thats not a problem for a 5770.

PCI Express 2.0 x16: 2 (one x16 or dual x8 link)

I still dont think you should buy that motherboard. It is an older 790 chipset and does not include USB3 or SATA3. For around the same price there will be a newer motherboard that does have those (and probably the newer 890 chipset).

Like this Gigabyte GA-890XA-UD3
http://www.newegg.com/Product/Product.aspx?Item=N82E16813128438

or cheaper ASRock 870 Extreme3
http://www.newegg.com/Product/Product.aspx?Item=N82E16813157198

 

[oddtodd]

Best answer selected by oddtodd.