# Who to believe? GPU-Z vs MSI Afterburner



## Luis Garcia (Jul 4, 2017)

Hello,

I've noticed that GPU-Z and MSI Afterburner show different values of memory clock:







My graphic card is MSI GeForce GTX 970 100ME. Screen above shows the card in IDLE. As you can see, Afterburner says that memory clock is 324 MHz and GPU-Z - 162 MHz, so question is simply: which utility is telling the truth? Which value is correct?


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## P4-630 (Jul 4, 2017)

Luis Garcia said:


> Hello,
> 
> I've noticed that GPU-Z and MSI Afterburner show different values of memory clock:
> 
> ...



Both are correct , it's GDDR5 , 162MHz x 2 = 324Mhz

http://www.geeks3d.com/20100613/tut...-clock-real-and-effective-speeds-demystified/


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## agent_x007 (Jul 4, 2017)

But why would you use DDR metric for GDDR5 ?
Can GDDR5 work in GDDR3 mode (for 2D states) ?

Because to me, QDR is QDR, and DDR is DDR.
You either use real values for frequency or effective values and effective values for GDDR5 memory should always be in QDR (ie. 4x real clock).

Also, what do you do with GDDR5X/GDDR6 ?
You have Real 1250MHz, DDR effective 2500MHz, QDR ("8n") effective of 5000MHz and "Octa" Data Rate (or QDR "16n") of 10 000MHz.
Which is the actual effective VRAM frequency for original GTX 1080 ?


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