nvidia 295 core clock lower then 4890

[deed]

http://www.newegg.com/Product/Product.aspx?Item=N82E16814150368
http://www.newegg.com/Product/Product.aspx?Item=N82E16814130510

I have been looking at alot of nvidia and ati cards, How come the nvidia cards have a lower core clock but perform better then the 4890 * they did atleast when I used them*

[Bobnova]

The cores are wildly different.
A P4 at 4ghz is roughly equal to one core of a core2duo at 2ghz, it's the same deal with GPUs (though neither sucks as badly as the P4s did).
ATI has a lot of relatively small cores at a high clock, nvidia has fewer larger cores at a lower clock.

[thideras]

Basically, it comes down to how much data the core can process per cycle. If it can process more, then a higher clockspeed is not needed.



Example:

Core 1 can process 2 pieces of data per cycle (1 Hz). It runs at a speed of 5 Hz and thus processes 10 pieces of data per second.

Core 2 can only process 1 piece of data per cycle (1 Hz). It has to run at a speed of 10 Hz to match the performance of Core 1.

As you can see, 'Core 1' in my example has half the "speed" of 'Core 2' when performance matches.



Unless they are the exact same core, you can't compare Hz to Hz.

[deed]

Basically, it comes down to how much data the core can process per cycle. If it can process more, then a higher clockspeed is not needed.



Example:

Core 1 can process 2 pieces of data per cycle (1 Hz). It runs at a speed of 5 Hz and thus processes 10 pieces of data per second.

Core 2 can only process 1 piece of data per cycle (1 Hz). It has to run at a speed of 10 Hz to match the performance of Core 1.

As you can see, 'Core 1' in my example has half the "speed" of 'Core 2' when performance matches.



Unless they are the exact same core, you can't compare Hz to Hz.

Ahh I see. So lets say I got the nvidia card and clocked it the same as the 4890 it would almost be twice as good?

[thideras]

Mine was just an example and has nothing to do with "real world numbers". It was purely for demonstration purposes. The nVidia cores are not "twice as good" as ATi, or vice versa.

[deed]

Mine was just an example and has nothing to do with "real world numbers". It was purely for demonstration purposes. The nVidia cores are not "twice as good" as ATi, or vice versa.

Yeah I understand now, I always knew what cards are best but I never knew 100% why haha. Even though if the default nvidia clock is half of ati' then it does seem to be almost double but i could be wrong.

[Bobnova]

If you could convince the 260 to clock to the same speed as a 4890 (you won't), then yeah it'd be faster.
That same effort put into overclocking the 4890 would make it faster too though.

[deed]

If you could convince the 260 to clock to the same speed as a 4890 (you won't), then yeah it'd be faster.
That same effort put into overclocking the 4890 would make it faster too though.

I see thanks.


Is nvidia ahead of ati in far of technology terms? It seems the 295's are about the same as the 5870's and they are brand spankin new. I thought that could also explain the larger price difference.

[Bobnova]

The 295 is simply two 275's sandwiched together, it's two cards and two GPUs.
When the 5870 x2 comes out, it'll stomp the 295, because it'll be two 5870 gpus against two 275's instead of one 5870 vs two 275s.

As of right now, nvidia is behind, that will change when their GT300 series comes out, then they'll be even technology wise, and probably have faster (but more expensive) cards, because that is the section they like to aim at.