Faster Memory and Core so why's it slower?

[WatchTower]

I'm taking about ATI's 3870 series. They have both faster memory and core but people keeps saying the Nvidia's 8800 series out performs them. I don't get it?

Still the ATI cards do look the best value.

 

[willhub]

I'm taking about ATI's 3870 series. They have both faster memory and core but people keeps saying the Nvidia's 8800 series out performs them. I don't get it?

Still the ATI cards do look the best value.

Because its not all about the clock speeds, basically the 8800's are more efficient and also there shaders run at like twice the speed.

 

[melbourne720]

Completely different architecture. You can only use clock speed to compare two cards with identical layout (e.g. 2 different brands of 3870s).

Think of it like this. Ati is a 3 lane motorway, with all the cars doing 70. NVidia is a 6 lane motorway, with all the cars doing 50. If there is a car in each lane, which has the more cars passing a particular point in each motorway? NVidia, because although the cars speed (clockspeed) is slower, the amount of cars (work being done) is greater because of the lanes (bandwidth).

Huge simplification, but you get the idea. Don't trust just clockspeed.

 

[spp]

Much the same way as it's you can't compare Intel and AMD chips via clock speed alone, totally different designs. When trying to choose a new card, its best to have a look at different reviews and tests, as well as asking people on forums. Don't pick up a card because it has a faster clock speed

 

[Gashman]

yeah even though the 3870 has 320 stream processors and 16 ROPs the 8800GTS (for example) has 128 stream processors running at (my speed) 2Ghz, its only the ROPs and other components that run at the core clock speed, so even though the ATI has far more stream processors they only run at 750Mhz (example) meaning there beaten almost three times in sheer clock speed compared to the NVIDIA offering, this huge difference in Mhz is what makes the 8800 series faster than the 3870 basically, theres more to it than that as well i believe

 

[Talrinys]

All about architecture mate

 

[Scougar]

Don't think you made that clear. Nvidia gains an advantage over ATI (at the moment) as they decided rather than Clock/Memory speeds they have Clock/Shader/Memory speeds.

The shader is now clocked much higher (2 or 3 times the clock speed), on Nvidia cards so any shader operations are MUCH faster compared to ATI's.


e.g.
Clock speed/ Memory Speed / Shader Speed
ATI 750/1200/750 (Shader running at same speed as clock)
Nvidia 600/1000/1750

That's one of the reasons. (and there are many)

Matthew