PCI-E x16 2.0 Slot (CFX x8)

[Ma-Xell]

Hi!, I'm building a PC.
I found this motherboard Biostar Tpower I45.
It has 2 PCI-E x16 2.0 (CFX x8) Slots. Does this mean that if I have one graphics card it will be using x16 and if there are 2 graphics cards they share and each get x8? Currently I'm planning to buy a PowerColor PCS+ HD4870 512MB. I do play many games on high resolution so in the future I might buy another card and run them in CrossFire. Would x8 be enough for this?

:thanks:
Graphics card:
http://www.powercolor.com/Global/products_features.asp?ProductID=2256

Mobo:
http://www.biostar.com.tw/app/en-us/t-power/content.php?S_ID=365

[CWR03]

Does this mean that if I have one graphics card it will be using x16 and if there are 2 graphics cards they share and each get x8?
Yes, so you'd basically waste most of the money spent on the second video card. I made the same mistake and got only a 5% performance boost and actually lost some higher-end rendering, like 16x anisotropic filtering on Crysis.

[Ma-Xell]

But then what is the point of 2 pic-e x16 slots, if they can't run 2 graphics cards properly at the same time?:confused:
In the motherboard specifications it does say "Support AMD CrossFire X Technology".

[LoRd_MuldeR]

In the motherboard specifications it does say "Support AMD CrossFire X Technology".

Just supporting something doesn't say anything about the quality/performance of the support :p

If you really intend to use CrossFire, get a board that connects it's two PCIe-x16-Slot with 16 lanes per slot (32 lanes in total). Not just 16 lanes shared by two slots.

[ghostonline]

pci-e 2.0 8x8 is sufficient for current video card generation. generally speaking, you will not see much, if any, difference between x8 and x16 mode for pci-e 2.0.

for games, not all games support cross-fire/sli. even supported, the percent of increase in performance is still a variable. if your games scale in crossfire very well, crossfire is an option.

[Ma-Xell]

so is PCI-E 2.0 x8 x8 enough for 2 HD4870s in CrossFire? :confused: but a non 2.0 x8 x8 is not?

[Ma-Xell]

Does anyone know a good and cheap motherboard which has 2 x16 x16 PCI-E slots (ATi CrossFire), cpu socket 775, ATX formfactor, DDR2 up 1200Mhz ram?
maybe: Gigabyte GA-X48-DS4

NewEGG INFO (http://www.newegg.com/Product/Product.aspx?Item=N82E16813128336)

:thanks:

[ghostonline]

ga- x48 is not really a cheap board.

anyway, if you want pci-e 2.0 x16 + x16, then it is a good board to get..


otherwise, any boards with P45 that support x8 + x8 mode is good enough for average user

in performance level, pci-e 2.0 x8 = pci-e 1.0 x16.

last thing, 4870 is nothing special. it belongs to current generation.

[RunningSkittle]

Tomshardware just did an article about crossfire scaling across different motherboards with 2 4870's. P45 looks like a very good option.
http://www.tomshardware.com/reviews/crossfire-pci-express,2095.html

http://media.bestofmicro.com/3/Q/171206/original/crossfire-scaling_10.png
http://media.bestofmicro.com/3/O/171204/original/crossfire-scaling_08.png
http://media.bestofmicro.com/3/W/171212/original/crossfire-scaling_16.png

[Ma-Xell]

ok thanks guys

I will stay wil biostar p45