[SOLVED] Effective memory clock speed confusions

[Proprietary Software]

Rtx 2080 has an actual clock of 1750mhz, but its effective memory clock is 14ghz. Don't you calculate the effective memory clock of graphics cards by multiplying the actual clocks by 4 (quad pumping)? Why is it octo pumped on the rtx 2080?

 

[Metal Messiah.]

Yes, you need to multiply by 4. One general example, not for your GPU though. The effective speed of a QDR memory can be calculated as given below: QDR = Quad Data Rate or Quad-pumped:

QDR_Effective_speed = Real_speed x 4.

e.g., 1750*4 = 7000 Mhz. Its DOUBLE DATA RATE and Quad pumped. Not octo.

It's GraphicsDoubleDataRate6 memory/RAM. GDDR6 is Double Data Rate memory.

So the effective frequency is 2 x 2 x base frequency = 2 x 2 x 1750 = 7000 MHz.

Make a note. It is GDDR (Graphics Double Data Rate,), so the memory will communicate on both the leading/ trailing edge of its pulses. MSI Afterburner will show you effective memory speeds, but GPU-Z on the other hand will show you the actual frequency. Double that number and it will match.

 

[Proprietary Software]

If GDDR is quad pumped, why is my effective memory clock speed 8 times the core clock speed?

 

[Metal Messiah.]

Are you talking about the 14000HMz effective speed ? It is advertised as 14000MHz, since its DOUBLE DATA RATE and Quad pumped. .

Also, the Memory clock is 14Gbps GDDR6, hence that value. 1750* 8= 14000. The VRAM itself has a bandwidth of 14Gbs

Memory Speed

14GHz

 

[Proprietary Software]

Are you talking about the 14000HMz effective speed ? It is advertised as 14000MHz, since its DOUBLE DATA RATE and Quad pumped. .

Also, the Memory clock is 14Gbps GDDR6, hence that value. 1750* 8= 14000. The VRAM itself has a bandwidth of 14Gbs

Memory Speed

14GHz

So it’s 1750 times 2 times 4?Why don’t other gpus have an effective memory clock 8 times the actual clock? Rx570, for instance, also has an actual clock of 1750mhz, but it’s effective clock is only 7000mhz.

 

[Metal Messiah.]

Because, the RX 570 features a different Memory bandwidth. The specs are totally different than the RTX 2080.

Memory Speed (Effective) value is 7 Gbps. So that's why it shows 7000Mhz.
Max Memory Size is 8 GB.
Memory Type (GPU): GDDR5
Memory Interface, 256-bit.
Max. Memory Bandwidth, 224 GB/s.

Is it clear now ?