Memory Clock and Memory Speed


Yes but it can be written differently. RAM is usually marketed at its effective speed not its actual speed. Regular desktop RAM is DDR or double data rate. It sends one piece of information on both the rising and falling edges of the clock cycle. This is also known as double pumped. So as an easy example DDR4 3200 actually runs at 1600Mhz but because it moves 2 pieces of information it's marketed at 3200mtp/s or mega transfers per second.

GDDR5 is quad pumped. It moves 2 pieces of info on each edge of the clock cycle for a total of 4. Now here's where it gets confusing because different companies list the speed differently but they are all correct. So you might have a card with GDDR5 10Gbp/s. This would have an actual clock speed of 2500Mhz ( x 4 because it's quad pumped ). BUT it could be marketed as 2500, 5000 or 10000 depending on what company is doing the marketing.

Hopefully that wasn't too confusing. Because it can be.

Edit: That doesn't even take into account AMD's HBM which is completely different.

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