What is my actual GPU speed - In plain simple English please?

[ianh]

Hi all, I have a KFA2 GTX 1080Ti EXOC which comes with a spec of -

• Core Clock: 1531MHz
• Boost Clock: 1645MHz
• Memory: 11010MHz

Yet when I test it in Unigine Heaven or Valley it says -

• Core Clock: 1961MHz
• Memory: 5505MHz

and in GPU-Z whilst running 3D Mark it gives -

• Core Clock: 1837MHz (but the figure varies wildly)
• Memory: 1377Mhz

and Afterburner says -

• Core Clock: 1835MHz
• Memory: 5508MHz

and several of the Benchmark threads show people with 1080Ti's giving speeds of 2000/3000 (core/memory?????) which is different again.

Can anyone explain in fairly "noob" language why the figures are all so wildly varied please?

Cheers...................................................................Ian

 

[LeMson]

Google gpu boost 3

 

[spoffle]

The cooler your GPU, the more the software will raise the GPU clock speed until it hits a power or temperature wall.

 

[ianh]

@LeMson - Thanks for that, I found this Reddit link very easy to understand and it at least explains the core speeds being much higher than stated on the box but I can't see anything about the hugely different memory speeds I've mentioned above.

 

[Rroff]

1377Mhz is the base clock speed - the numbers get a bit complex after that because DDR by its name can do memory operations on both the rising and falling side of the clock signal hence "double data rate" so you effectively have RAM that is effectively twice as fast as single data rate RAM at the same base clock but then it gets more complex again as GDDR5 can do several operations on each rising and falling clock and GDDR5X can do double again what GDDR5 can do so the "effective" speed of GDDR5X is in this case 11GHz but some programs will still calculate it as half that as it would GDDR5 (some programs will also show say "5GHz" GDDR5 as 2.5GHz due to not properly calculating it).

 

[ianh]

@Rroff Thanks for the info. Now it makes sense that all the memory speeds are a function of the 1377 base clock so 5505 = base x4 & 11010 is base x8 etc.

Thanks for the education guys!

 

[Danny75]

And you can ignore the Heaven/Valley core clocks, they've been wrong for ages. Usually it adds 100+, although I played with a GTX 780 Inno3D bla bla (long name) to which it added 200MHz.