P45 vs x48 for Radeon 4870x2

[blogz101]

What is better for radeon 4870x2 ? I mean will there any performance loss if i put a 4870x2 on the p45 chipset?

 

[JPB]

No, there will be no loss. It will run identically to the X48 with one card installed.

Do you plan on a single pci-e board or one for Crossfire ?

The X48 is 16x/16x speed where as the P45 is not. <----Only difference really.

 

[blogz101]

oh for the moment i guess ill just run 1 4870x2, really dont need 2 4870x2.

 

[Phunk0ne]

c'mon, where is the sport in running "only" 1 X2

 

[Howie]

Slightly off topic but relevant. Say I was to run two 4870s or 4850s. How much of a performance boost will I see going with an X48?

 

[Nickel020]

About 5-15%, depending on the game:
http://www.legionhardware.com/document.php?id=761&p=2

 

[Howie]

Originally posted by: Nickel020
About 5-15%, depending on the game:
http://www.legionhardware.com/document.php?id=761&p=2

Thanks for the link. That is the first time I saw comparisons like that. Considering the price difference, between top X48 and P45 boards, it's a hard call for that extra 5-15%.

 

[sgrinavi]

Originally posted by: Howie

Originally posted by: Nickel020
About 5-15%, depending on the game:
http://www.legionhardware.com/document.php?id=761&p=2

Thanks for the link. That is the first time I saw comparisons like that. Considering the price difference, between top X48 and P45 boards, it's a hard call for that extra 5-15%.

I don't know about the P45 boards but I can say that the x38 and x48 boards overclock very easily. It took me minutes to get a better OC on both of my current boards than what took me a week to do on my p35's. No brainer, even with 8GB of cheap RAM.

15% performance increase could make a big difference. That is what I consider substantial.

 

[texasreefer]

I don't know about the P45 boards but I can say that the x38 and x48 boards overclock very easily. It took me minutes to get a better OC on both of my current boards than what took me a week to do on my p35's. No brainer, even with 8GB of cheap RAM.

15% performance increase could make a big difference. That is what I consider substantial.

That is very interesting sgrinavi. Another reason could be the difference is the brand of board. I have had alot better results overclocking with Asus, as opposed to ABit. And a buddy of mine, Nvidia Fan, cannot get his 780i EVGA board to to run stable at 3.6 through mucho a trial and tweak.

I've noticed a difference between ASUS and EVGA also, i.e. - Q6600 stable at 3.6, and EVGA 780i stable at 3.35 with the same model CPU and RAM. It seems that people with EVGA boards (running DDR2) need more than 900Mhz to achieve 3.6 Ghz.

On a different note, the data/graph is very interesting Nickel020 because at Higher Resolutions (1920 x 1200) there is less than one percent difference. P45s run at 8x/8x lanes in crossfire, and it's actually one 16x lane split into two. The fact that there is no significant difference has to make me raise an eyebrow.

Are 16x/16x crossfire/SLI lanes faster than 8x/8x?

 

[killbydemons]

Modern video cards probably don't use up all of the available bandwidth provided by 16 lanes. Just like most apps don't benefit from DDR3 over DDR2 (except for synthetic benchmarks of course), there just isn't a need for that much bandwidth in typical computing...even if you are a "high end" gamer .

 

[texasreefer]

Well the data in question was run on 2 4850s.

I wonder what will happen if 24870X2s are crossfired? That should increase the bandwidth and info. flow. I know it doubles the Bus Width of 2 4850s.

Only thing stopping me from going 2 4870X2s is my 750W PcPower (4870X2s run at about 430Ws each at load). That and the fact that they are not on the market yet.