260 GTX (N26OC-896I) memory clock speeds

[Kavman]

Hi, i have just received a pair of 260 GTX (N26OC-896I) cards, and after installing the Gigabyte Hud, i noticed the memory clock speed is reading 1000mhz whereas the specification reads 2000 mhz. Will these cards safely run at 2000mhz clock speed if i manually adjusted the dial on the gigabyte gamer hud?, and why arent these cards stock clocked at that clock speed to begin with?

[Pottypete]

Hi,
You tried hitting the Auto Clock setting  button in lower left,?
regards

[Kavman]

Hi, yes the auto optimized button is enabled. I understand from reading the FAQ section that gpu clocks change for power saving etc depending what app you are running. However the gpu core clock and shader clock stay fixed at their specs and memory clock stays fixed at 1000mhz. I have alt-tabbed out of games to check whether the memory clock has increased automatically, but it stays at 1000 mhz.

[Pottypete]

Hi,
Crank it up 
If it causes a problem it will reset to default,
Regards

Don't listen to me i'm potty, and live life a the edge

[Badbonji]

Wait a sec there!
The programme is obviously reading the true clock speed of the memory, rather than the effective. What is special about GDDR / DDR memory, regardless of 1/2/3/4/5 etc... is that the memory is double data rate, meaning effectively per each clock cycle two instructions can be handled. So, when some programmes say exactly half of what you are expecting, then more than likely it is showing the actual speed rather than effective. If you tried to overclock it, then you would have gone for a 4000Mhz memory clock which would have caused major artifacting, likely instantaneous driver crash/ pc hang under 3d load and could damage the memory.

An example is running DDR2. Say the FSB of the cpu was 333Mhz, if you chose to run the memory at a 1:1 DRAM:FSB ratio (equal clocks) then both the FSB and memory would run at 333Mhz, but being double data rate, the memory would be effectively running at 666Mhz (or 667Mhz).

[Kavman]

Thanks for the explanation Badbonji, i suppose thats what ddr stands for . I knew something was up when reading other cards clockspeeds off software. Gaming performance is excellent, so i wasn't about to overclock them. Glad i don't have 2 fried 260's anyway 

[Badbonji]

No problem, I agree it can be confusing, as some programmes show the effective and others the actual (same for RAM speeds).