HD4850 crossfire dual x8 versus x16

hhahaahyea

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i've seen so many benchmarks etc. about dual x8 vs dual x16 and i've gotten so many different results.

i recently bought a 4850 and i'm using it on my pci-e 1.0 motherboard at the moment. (which is performing amazingly well. runs crysis very high and is totally playable.) gpu-z says i'm getting 67.2 GB/sec bandwidth. i don't have anything to compare that to though, is that good/bad?

i'm looking to get a 4850 crossfire setup and was looking at this board
http://www.newegg.com/Product/Product.aspx?Item=N82E16813130172
which runs x8/x8. it's really cheap for a pci-e 2.0 board, but would it be worth it to get a board that runs x16/x16?
the x16/x16 ones i've seen are basically twice as much. is it worth it?

OR

if i don't go the crossfire route would it even be worth it to buy a new motherboard to upgrade to pci-e 2.0?


thanks :sleep:
 

SonDa5

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Most 3dMark06 benchmarks show about a 30% performance increase.

It's all about choices. Getting solid MB that offers stability along with support for user hardware is a good way to go to start.

DFI has a new mATX MB coming out soon that support Xfire.
I'm thinking about getting it and I have been thinking about the dual 8x situation as well.

Seems like a huge bottleneck to get into for what I estimate to be about 30% performance increase.
 

hhahaahyea

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awesome. i like very much. i thought i checked out this board before and it was more expensive, but apparently i missed something.

i'll probably go with this board then. thanks.
 
No problem.

I hope you have a case with good cooling. You'll need it because the HD 4850 doesn't have vents and the case fans must remove the heat.

What kind of PSU do you have?

 

hhahaahyea

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yeah. currently i have a 500W which won't do crossfire. i'm trying to sell my current computer and do a complete upgrade.

but if i can't do that, this case has really good cooling. and i did the fan fix in the CCC files and my 4850 is at 650/1050 at 45 degrees idle and 65 degrees load.
 
LOL, and they say the HD 4850 is hot. My 8800GTX is at 72 degrees right now, and all I'm doing is surf the Web and watch Stargate on the second monitor. And your HD 4850 is way faster too... That 55nm technology is sure doing its job :)

There's a nice sale at the 750TX PSU at newegg, if you want.
 

geckoar

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I own the K9A2 790FX MB and its great. I got it for 149.00 at newegg in march. It has 4 PCIx 2.0 slots and its a good layout... for the most part. I cant get a PCIx sound card because the 1X slot is right next to the main 16x slot. My dual slot HD 3870 blocks it. But for the bandwidth My 3870 is 79.5 GB/s and I has the speed at 864/1242 up from 851/1143. Idle is at 33c and load running ATI tool is around 56c. But for the bandwidth my card has GDDR4 and not GDDR3 men. like the 4850.
 

hhahaahyea

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yeah i hear pcie2 x8 = pcie1 x16

but if my 4850s are gonna use the bandwidth then i wouldn't want to bottleneck them, especially if it's only $50 more. if the 4850s are designed for pci-e 2.0 then eventually games/drivers will require/support the extra bandwidth, correct?


also, aevm, i'm running my fan at 60%. i guess it's a bit noisy (hardly louder than my case fans, and i can't hear it while gaming whatsoever, but some people are picky about that.) when i got it the fan ran at 10% or 15% or something and was 70-90 degrees. and i didn't like it that hot. geckoars running his really low though, that's always nice.


but sweet. i'm gonna go with that board then. the 4850s are single slot so it should be fine. if i can sell my comptuer, and i'm looking at this case:
http://www.newegg.com/Product/Product.aspx?Item=N82E16811294003
becuase it looks like a jet. and should have good cooling for my cards.

appreciate your help guys.