I was using a third party benchmark utility, HD Tach RW. You need the registered version to do write testing and it destroys the data on the SD card, so you have to be careful. The 80X or 150X is so meaningless when it comes to digital camera's because it is the write speed that is important, and you can only hope that the maker of a 150X card is going to match that high speed read rate with a high speed write rate, but there is no way of telling, and in the case of A-data, they certainly didn't. I've actually had some time to benchmark some of my usb flash drives and have seen some strange results there too. I have an older PNY 512mb flash drive that reads at 133X, a year after that, thinking its performance was very good, I bought the same model, but with 1GB. You'd hope the newer higher capacity drive would be equally but it was only about a 60X drive. These manufacturers aren't required to disclose the speeds of these devices, and can change the spec simply due to cost or part availabilty. I have 2 of the exact same drives that are light years apart in speed.
