GPU Questions

[Flatlander]

Hi

I am looking for a GTX 460 and have noticed that some of them are sold as overclocked. Yet when I read the reviews they are saying that they have to be overclocked in Windows. As I'll be using Ubuntu I need to know if I will be able to overclock. Is there a utility for this?

Having built a fairly quiet system I'm also concerned about noise. Do you think that an overclocked GPU just a few feet from me would be excessively noisy? (Subjective, I know.)

I have narrowed it down to 2 (from my fave shop) the first is (or can be) overclocked more than the second, but the second has 2Gb ram. Would the extra ram be useful at all? LLR, PGFW and sieving are what I'm doing. I don't think I would have the patience for GIMPS work.


http://www.ebuyer.com/product/232640
http://www.ebuyer.com/product/234943
(I need the VGA port.)

Thanks in advance for any advice.

[Ken_g6]

As far as I know, the only way to overclock in Linux is to re-flash the BIOS. That may change in the future. When they come overclocked, their BIOS has already been re-flashed to that overclock.

I doubt the extra RAM would be useful for anything but gaming.

Have you considered a GTX 560? They're clocked higher, have a few more cores, but still run cooler than an overclocked 460, from what I hear.

[Flatlander]

Originally Posted by Ken_g6

...
Have you considered a GTX 560? They're clocked higher, have a few more cores, but still run cooler than an overclocked 460, from what I hear.

A looked briefly and saw they used more watts, so assumed more heat. I'll do some more research.
Also, I didn't see one with a VGA port. I'll have to check the back of my monitor.

[Ken_g6]

Originally Posted by Flatlander

A looked briefly and saw they used more watts, so assumed more heat. I'll do some more research.
Also, I didn't see one with a VGA port. I'll have to check the back of my monitor.

Oh, I forgot to mention, 99% of graphics cards these days use DVI, but include a DVI to VGA dongle. If there's a picture of all the accessories, software, etc. that comes with your card, it's usually shown there.

Edit: 10 Watt difference in heat output at stock. Overclocking increases heat too.

[Flatlander]

Originally Posted by Ken_g6

Oh, I forgot to mention, 99% of graphics cards these days use DVI, but include a DVI to VGA dongle. If there's a picture of all the accessories, software, etc. that comes with your card, it's usually shown there.

That helps. Thanks!

[nucleon]

Originally Posted by Ken_g6

I doubt the extra RAM would be useful for anything but gaming.

To clarify....

From reading the forums here, it appears FFT based code (LL etc...) is predominately memory bandwidth limited on the GPUs. So far I haven't seen any code here on this forum that's memory _size_ limited.

The "GTX460" 768MB card has a memory bus of 192bits, the 1GB & 2GB cards have 256bit, the GTX470 has 320bit, and the GTX480 has 384bit.

So going from 768MB GTX460 card to the 1GB card will see memory throughput improvement. Going from 1GB to 2GB will see little difference in the current CUDA code on the forums.


More info:
http://en.wikipedia.org/wiki/Compari...ocessing_units

-- Craig

[ldesnogu]

Originally Posted by Ken_g6

As far as I know, the only way to overclock in Linux is to re-flash the BIOS. That may change in the future. When they come overclocked, their BIOS has already been re-flashed to that overclock.

nVidia drivers have allowed overclocking for years under Linux, though it seems this is not yet implemented for Fermi, but supposed to come

Ref: Phoronix