Radeon HD 3870 CoD4 AA performance

[Bradtechonline]

2x or even 4x at 1680x1050 really makes my card crawl.. As soon as I disable AA even with 16x AF and high textures I'll hit 60-90 fps and its very playable with minimial lag.. Anti Aiasing enabled however just kills the card.. This normal you guys think? I bet a 4870 would and CPU upgrade would help..

 

[BFG10K]

Yes, this is normal and yes, the 4870 will help immensely.

The 3xxx (and 2xxx) series performed AA resolve for the box modes on the shaders, hence the steep performance hit. The 4xxx series not only performs box modes on the hardware ROPs instead, the ROPs themselves have been substantially improved over the 3xxx/2xxx line.

At 1600x1200 with 4xAA, a 4870 is almost three times faster than the 3870 in CoD 4:

http://www.computerbase.de/art...schnitt_call_of_duty_4

 

[Modular]

What are your AA settings in the driver control panel? If you're using 4x + edge detect, then it's really equal to 24x AA.

 

[Bradtechonline]

Time to sell my good ole buddy then.. They just don't last as long like they used to ).

Originally posted by: BFG10K
Yes, this is normal and yes, the 4870 will help immensely.

The 3xxx (and 2xxx) series performed AA resolve for the box modes on the shaders, hence the steep performance hit. The 4xxx series not only performs box modes on the hardware ROPs instead, the ROPs themselves have been substantially improved over the 3xxx/2xxx line.

At 1600x1200 with 4xAA, a 4870 is almost three times faster than the 3870 in CoD 4:

http://www.computerbase.de/art...schnitt_call_of_duty_4

 

[SonicIce]

Would the same hit happen in CS:S? Because my friend always complains his fps drops a whole lot in that game when he tries to use AA. He has the 3870 and uses 1680x1050.

 

[vj8usa]

Originally posted by: Modular
What are your AA settings in the driver control panel? If you're using 4x + edge detect, then it's really equal to 24x AA.

4x edge detect is equivalent to 12xAA. 8x edge detect is what's like 24xAA. That's a good point though; edge detect will hurt performance more than box.

 

[evolucion8]

Originally posted by: vj8usa

Originally posted by: Modular
What are your AA settings in the driver control panel? If you're using 4x + edge detect, then it's really equal to 24x AA.

4x edge detect is equivalent to 12xAA. 8x edge detect is what's like 24xAA. That's a good point though; edge detect will hurt performance more than box.

The HD 4x00 series also uses shaders to resolve anti aliasing when the tent filters and edge detect are used, the funny thing is that they're still faster than in the HD 3870 until a certain point that both runs almost at identical speed, I heard that it was because since the HD 3870 had broken ROP's, they did had a fast data path to solve anti aliasing in shader that the HD 4800 series lack and there's a bottleneck in a certain point.

Originally posted by: BFG10K
Yes, this is normal and yes, the 4870 will help immensely.

The 3xxx (and 2xxx) series performed AA resolve for the box modes on the shaders, hence the steep performance hit. The 4xxx series not only performs box modes on the hardware ROPs instead, the ROPs themselves have been substantially improved over the 3xxx/2xxx line.

At 1600x1200 with 4xAA, a 4870 is almost three times faster than the 3870 in CoD 4:

http://www.computerbase.de/art...schnitt_call_of_duty_4

It's has been a while since the last time we saw such a performance jump between generations, like the Radeon 9800/GeForce FX era to the X800/GeForce 6 era...

 

[BFG10K]

Originally posted by: Bradtechonline

Time to sell my good ole buddy then.. They just don't last as long like they used to ).

To be fair, this particular series was already crippled with AA when it first came out. But before you do anything check you aren't running edge-detect in your control panel, as others have pointed out already.

Originally posted by: SonicIce

Would the same hit happen in CS:S?

Yes, it'll happen in any game that is being run at GPU bound settings.