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kenny_k
09-06-07, 10:11 AM
Quick question on the 8800's frequency range. If all the settings between 618-634 sets the clock speed to 621 and shader to 1458 what difference is does it make setting it either below or above 621???

ATOJAR
09-06-07, 10:19 AM
Hu? I have my frequency at 626MHz and my graphics card runs at 626MHz! ... my shaders are at 1458MHz.

My clock speeds stay at 626MHz right up untill i chance the frequency to 630MHz then the clock speeds run at 630MHz, with my frequency at 634 my clock speeds read as 632MHz!

Eliminator
09-06-07, 11:09 AM
take a look here
http://www.madshrimps.be/?action=gethowto&number=3&howtopage=190&howtoID=72

kenny_k
09-06-07, 11:26 AM
Hi Atojar, these were the frequencies I was referring to:
http://www.mvktech.net/component/option,com_joomlaboard/Itemid,34/func,view/id,44632/catid,10/

When I open the "Hardware Monitor" in Rivatuner, it will display 621 as the core clock for any setting I make within that range.

ATOJAR
09-06-07, 11:43 AM
Take a look below!

kenny_k
09-06-07, 11:48 AM
take a look here
http://www.madshrimps.be/?action=gethowto&number=3&howtopage=190&howtoID=72

That's my question. Is there any difference by me setting my clock to either 618 or 630 since the 8800 will set the real clock to 621 and shader to 1458 in either case?

ATOJAR
09-06-07, 11:57 AM
Im not 100% sure, i really cant see it making a difference to be honest as its not actually your clock speeds that are changing, as i said i can set my frequency to anywhere beteen 624 - 629 and my clock speeds will still stay at 626MHz .... i just flashed the bios to 626MHz anyway.

kenny_k
09-06-07, 01:27 PM
Im not 100% sure, i really cant see it making a difference to be honest as its not actually your clock speeds that are changing, as i said i can set my frequency to anywhere beteen 624 - 629 and my clock speeds will still stay at 626MHz .... i just flashed the bios to 626MHz anyway.

Possibly changing it in the bios has a different effect??? If I set it anywhere in between those ranges using AtiTool or Rivatuner the Hardware Monitor in RivaTuner will show 621 as the clock speed.

ATOJAR
09-06-07, 01:45 PM
Yip looks that way ... when i think back now i think mine was like yours before i updated the bios!

EDIT: well when i say "updated the bios" what i ment was flashed it with the EVGA 8800GTS (KO.ACS³) PCIe 640MB - Rev 02 bios.

Slammin
09-06-07, 03:52 PM
That's my question. Is there any difference by me setting my clock to either 618 or 630 since the 8800 will set the real clock to 621 and shader to 1458 in either case?


That's exactly what that article is saying. You can set it to 625, but the clock will actually be set to 621, and run at 621. I see the same effect on memory too because it has these 'set points' as well. Also, you can see that shader clock follows core clock and it too has it's own 'set points'.

kenny_k
09-07-07, 01:12 PM
That's exactly what that article is saying. You can set it to 625, but the clock will actually be set to 621, and run at 621. I see the same effect on memory too because it has these 'set points' as well. Also, you can see that shader clock follows core clock and it too has it's own 'set points'.
Hi Slammin, and that's why I ask the question. Would you see any benefit setting it 630 when all its going to do is set it to 621? So setting it at 617 or 630 should get you the same performance results cause they'll both be set to 621???

john19055
09-07-07, 02:51 PM
No you want see any benifit at setting your core at 617 or 630 because it will default to 621.

Blacklash
09-07-07, 03:33 PM
My advice would be to test it yourself. There are plenty of benches out there that will reveal how much gain may be had at various steps. Or simply OC your card at various speeds and play your favorite game. Then you may decide if OC X is worth it to you.

Another interesting article is one Anand did on core and shader clock scaling:

http://www.anandtech.com/video/showdoc.aspx?i=2931&p=1

BCKator
09-08-07, 01:34 PM
This has been discussed before. I too see no frequencies between 621 and 648 (per rivatuner monitor). FWIW, my GTX jumps between 594,612,621, and 648. I read somewhere that the delta is 17MHz and, except for 648-621=27, I basically see that. 648 led to quick lockups on air but is semi-reliable on water.

To confirm riva's reported frequencies, I did my own testing using ATiTool 3D via and plotted the ave fps vs time and based on that I believe what rivatuner is reporting and expect no performance differences as a function of the set frequency, just the actual frequency as reported by rivatuner.