mersenneforum.org  

Go Back   mersenneforum.org > Great Internet Mersenne Prime Search > Hardware > GPU Computing

Reply
 
Thread Tools
Old 2011-02-04, 20:24   #1
Flatlander
I quite division it
 
Flatlander's Avatar
 
"Chris"
Feb 2005
England

40358 Posts
Default GPU Questions

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.
Flatlander is offline   Reply With Quote
Old 2011-02-04, 23:28   #2
Ken_g6
 
Ken_g6's Avatar
 
Jan 2005
Caught in a sieve

1100010102 Posts
Default

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.
Ken_g6 is offline   Reply With Quote
Old 2011-02-04, 23:49   #3
Flatlander
I quite division it
 
Flatlander's Avatar
 
"Chris"
Feb 2005
England

31×67 Posts
Default

Quote:
Originally Posted by Ken_g6 View Post
...
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.

Last fiddled with by Flatlander on 2011-02-04 at 23:51
Flatlander is offline   Reply With Quote
Old 2011-02-04, 23:54   #4
Ken_g6
 
Ken_g6's Avatar
 
Jan 2005
Caught in a sieve

2·197 Posts
Default

Quote:
Originally Posted by Flatlander View Post
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.

Last fiddled with by Ken_g6 on 2011-02-05 at 00:01
Ken_g6 is offline   Reply With Quote
Old 2011-02-04, 23:57   #5
Flatlander
I quite division it
 
Flatlander's Avatar
 
"Chris"
Feb 2005
England

31×67 Posts
Default

Quote:
Originally Posted by Ken_g6 View Post
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!
Flatlander is offline   Reply With Quote
Old 2011-02-05, 00:36   #6
nucleon
 
nucleon's Avatar
 
Mar 2003
Melbourne

10000000112 Posts
Default

Quote:
Originally Posted by Ken_g6 View Post
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
nucleon is offline   Reply With Quote
Old 2011-02-06, 00:17   #7
ldesnogu
 
ldesnogu's Avatar
 
Jan 2008
France

24×3×11 Posts
Default

Quote:
Originally Posted by Ken_g6 View Post
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
ldesnogu is offline   Reply With Quote
Reply

Thread Tools


Similar Threads
Thread Thread Starter Forum Replies Last Post
Two questions: Dubslow GPU Computing 1 2011-08-05 18:22
Questions about the QS Carmichael Factoring 8 2007-04-10 11:30
Questions OmbooHankvald Prime Sierpinski Project 2 2005-08-01 20:18
LLR questions OmbooHankvald Math 6 2005-06-23 11:42
A few questions :) xtreme2k Lounge 59 2002-10-31 06:20

All times are UTC. The time now is 04:59.

Tue Aug 11 04:59:26 UTC 2020 up 25 days, 46 mins, 1 user, load averages: 3.75, 3.25, 3.01

Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2020, Jelsoft Enterprises Ltd.

This forum has received and complied with 0 (zero) government requests for information.

Permission is granted to copy, distribute and/or modify this document under the terms of the GNU Free Documentation License, Version 1.2 or any later version published by the Free Software Foundation.
A copy of the license is included in the FAQ.