I bought 3-4 months ago a new video card from MSI ( R7770-PMD1GD5 ) , which I was thinking was good but after testing it for a week , i was very disappointing . Anyway today I have just seen an article about Overclocking so I said "Why not to try it" and accidentally i found tht my video card Memory Clock Speed was only 1000 Mhz . I said that the program was wrong so I tested it with GPU-Z and the same result .. My video card is running only with 1000 Mhz Memory Speed when it should tun on 4500 mhz .
My question is : "Why only 1000 Mhz . !?!?" I checked on the website I bought it and also on the MSI Official website and it said clear that this videocard normally moust have 4500 MHZ Memory Clock .
That is showing perfectly correct. 7770's uses GDDR5 memory which is quad data rate memory. Your GPU-Z shows the base (real) memory clock speed then you times that by 4 for the effective memory clock speed.